builtins.txt 88 KB

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  1. ==================================
  2. Built-in template tags and filters
  3. ==================================
  4. This document describes Django's built-in template tags and filters. It is
  5. recommended that you use the :doc:`automatic documentation
  6. </ref/contrib/admin/admindocs>`, if available, as this will also include
  7. documentation for any custom tags or filters installed.
  8. .. _ref-templates-builtins-tags:
  9. Built-in tag reference
  10. ======================
  11. .. templatetag:: autoescape
  12. ``autoescape``
  13. --------------
  14. Controls the current auto-escaping behavior. This tag takes either ``on`` or
  15. ``off`` as an argument and that determines whether auto-escaping is in effect
  16. inside the block. The block is closed with an ``endautoescape`` ending tag.
  17. Sample usage:
  18. .. code-block:: html+django
  19. {% autoescape on %}
  20. {{ body }}
  21. {% endautoescape %}
  22. When auto-escaping is in effect, all content derived from variables has HTML
  23. escaping applied before placing the result into the output (but after any
  24. filters are applied). This is equivalent to manually applying the
  25. :tfilter:`escape` filter to each variable.
  26. The only exceptions are variables already marked as "safe" from escaping.
  27. Variables could be marked as "safe" by the code which populated the variable,
  28. by applying the :tfilter:`safe` or :tfilter:`escape` filters, or because it's
  29. the result of a previous filter that marked the string as "safe".
  30. Within the scope of disabled auto-escaping, chaining filters, including
  31. :tfilter:`escape`, may cause unexpected (but documented) results such as the
  32. following:
  33. .. code-block:: html+django
  34. {% autoescape off %}
  35. {{ my_list|join:", "|escape }}
  36. {% endautoescape %}
  37. The above code will output the joined elements of ``my_list`` unescaped. This
  38. is because the filter chaining sequence executes first :tfilter:`join` on
  39. ``my_list`` (without applying escaping to each item since ``autoescape`` is
  40. ``off``), marking the result as safe. Subsequently, this safe result will be
  41. fed to :tfilter:`escape` filter, which does not apply a second round of
  42. escaping.
  43. In order to properly escape every element in a sequence, use the
  44. :tfilter:`escapeseq` filter:
  45. .. code-block:: html+django
  46. {% autoescape off %}
  47. {{ my_list|escapeseq|join:", " }}
  48. {% endautoescape %}
  49. .. templatetag:: block
  50. ``block``
  51. ---------
  52. Defines a block that can be overridden by child templates. See
  53. :ref:`Template inheritance <template-inheritance>` for more information.
  54. .. templatetag:: comment
  55. ``comment``
  56. -----------
  57. Ignores everything between ``{% comment %}`` and ``{% endcomment %}``.
  58. An optional note may be inserted in the first tag. For example, this is
  59. useful when commenting out code for documenting why the code was disabled.
  60. Sample usage:
  61. .. code-block:: html+django
  62. <p>Rendered text with {{ pub_date|date:"c" }}</p>
  63. {% comment "Optional note" %}
  64. <p>Commented out text with {{ create_date|date:"c" }}</p>
  65. {% endcomment %}
  66. ``comment`` tags cannot be nested.
  67. .. templatetag:: csrf_token
  68. ``csrf_token``
  69. --------------
  70. This tag is used for CSRF protection, as described in the documentation for
  71. :doc:`Cross Site Request Forgeries </ref/csrf>`.
  72. .. templatetag:: cycle
  73. ``cycle``
  74. ---------
  75. Produces one of its arguments each time this tag is encountered. The first
  76. argument is produced on the first encounter, the second argument on the second
  77. encounter, and so forth. Once all arguments are exhausted, the tag cycles to
  78. the first argument and produces it again.
  79. This tag is particularly useful in a loop:
  80. .. code-block:: html+django
  81. {% for o in some_list %}
  82. <tr class="{% cycle 'row1' 'row2' %}">
  83. ...
  84. </tr>
  85. {% endfor %}
  86. The first iteration produces HTML that refers to class ``row1``, the second to
  87. ``row2``, the third to ``row1`` again, and so on for each iteration of the
  88. loop.
  89. You can use variables, too. For example, if you have two template variables,
  90. ``rowvalue1`` and ``rowvalue2``, you can alternate between their values like
  91. this:
  92. .. code-block:: html+django
  93. {% for o in some_list %}
  94. <tr class="{% cycle rowvalue1 rowvalue2 %}">
  95. ...
  96. </tr>
  97. {% endfor %}
  98. Variables included in the cycle will be escaped. You can disable auto-escaping
  99. with:
  100. .. code-block:: html+django
  101. {% for o in some_list %}
  102. <tr class="{% autoescape off %}{% cycle rowvalue1 rowvalue2 %}{% endautoescape %}">
  103. ...
  104. </tr>
  105. {% endfor %}
  106. You can mix variables and strings:
  107. .. code-block:: html+django
  108. {% for o in some_list %}
  109. <tr class="{% cycle 'row1' rowvalue2 'row3' %}">
  110. ...
  111. </tr>
  112. {% endfor %}
  113. In some cases you might want to refer to the current value of a cycle
  114. without advancing to the next value. To do this,
  115. give the ``{% cycle %}`` tag a name, using "as", like this:
  116. .. code-block:: html+django
  117. {% cycle 'row1' 'row2' as rowcolors %}
  118. From then on, you can insert the current value of the cycle wherever you'd like
  119. in your template by referencing the cycle name as a context variable. If you
  120. want to move the cycle to the next value independently of the original
  121. ``cycle`` tag, you can use another ``cycle`` tag and specify the name of the
  122. variable. So, the following template:
  123. .. code-block:: html+django
  124. <tr>
  125. <td class="{% cycle 'row1' 'row2' as rowcolors %}">...</td>
  126. <td class="{{ rowcolors }}">...</td>
  127. </tr>
  128. <tr>
  129. <td class="{% cycle rowcolors %}">...</td>
  130. <td class="{{ rowcolors }}">...</td>
  131. </tr>
  132. would output:
  133. .. code-block:: html+django
  134. <tr>
  135. <td class="row1">...</td>
  136. <td class="row1">...</td>
  137. </tr>
  138. <tr>
  139. <td class="row2">...</td>
  140. <td class="row2">...</td>
  141. </tr>
  142. You can use any number of values in a ``cycle`` tag, separated by spaces.
  143. Values enclosed in single quotes (``'``) or double quotes (``"``) are treated
  144. as string literals, while values without quotes are treated as template
  145. variables.
  146. By default, when you use the ``as`` keyword with the cycle tag, the
  147. usage of ``{% cycle %}`` that initiates the cycle will itself produce
  148. the first value in the cycle. This could be a problem if you want to
  149. use the value in a nested loop or an included template. If you only want
  150. to declare the cycle but not produce the first value, you can add a
  151. ``silent`` keyword as the last keyword in the tag. For example:
  152. .. code-block:: html+django
  153. {% for obj in some_list %}
  154. {% cycle 'row1' 'row2' as rowcolors silent %}
  155. <tr class="{{ rowcolors }}">{% include "subtemplate.html" %}</tr>
  156. {% endfor %}
  157. This will output a list of ``<tr>`` elements with ``class``
  158. alternating between ``row1`` and ``row2``. The subtemplate will have
  159. access to ``rowcolors`` in its context and the value will match the class
  160. of the ``<tr>`` that encloses it. If the ``silent`` keyword were to be
  161. omitted, ``row1`` and ``row2`` would be emitted as normal text, outside the
  162. ``<tr>`` element.
  163. When the silent keyword is used on a cycle definition, the silence
  164. automatically applies to all subsequent uses of that specific cycle tag.
  165. The following template would output *nothing*, even though the second
  166. call to ``{% cycle %}`` doesn't specify ``silent``:
  167. .. code-block:: html+django
  168. {% cycle 'row1' 'row2' as rowcolors silent %}
  169. {% cycle rowcolors %}
  170. You can use the :ttag:`resetcycle` tag to make a ``{% cycle %}`` tag restart
  171. from its first value when it's next encountered.
  172. .. templatetag:: debug
  173. ``debug``
  174. ---------
  175. Outputs a whole load of debugging information, including the current context
  176. and imported modules. ``{% debug %}`` outputs nothing when the :setting:`DEBUG`
  177. setting is ``False``.
  178. .. templatetag:: extends
  179. ``extends``
  180. -----------
  181. Signals that this template extends a parent template.
  182. This tag can be used in two ways:
  183. * ``{% extends "base.html" %}`` (with quotes) uses the literal value
  184. ``"base.html"`` as the name of the parent template to extend.
  185. * ``{% extends variable %}`` uses the value of ``variable``. If the variable
  186. evaluates to a string, Django will use that string as the name of the
  187. parent template. If the variable evaluates to a ``Template`` object,
  188. Django will use that object as the parent template.
  189. See :ref:`template-inheritance` for more information.
  190. Normally the template name is relative to the template loader's root directory.
  191. A string argument may also be a relative path starting with ``./`` or ``../``.
  192. For example, assume the following directory structure:
  193. .. code-block:: text
  194. dir1/
  195. template.html
  196. base2.html
  197. my/
  198. base3.html
  199. base1.html
  200. In ``template.html``, the following paths would be valid:
  201. .. code-block:: html+django
  202. {% extends "./base2.html" %}
  203. {% extends "../base1.html" %}
  204. {% extends "./my/base3.html" %}
  205. .. templatetag:: filter
  206. ``filter``
  207. ----------
  208. Filters the contents of the block through one or more filters. Multiple
  209. filters can be specified with pipes and filters can have arguments, just as
  210. in variable syntax.
  211. Note that the block includes *all* the text between the ``filter`` and
  212. ``endfilter`` tags.
  213. Sample usage:
  214. .. code-block:: html+django
  215. {% filter force_escape|lower %}
  216. This text will be HTML-escaped, and will appear in all lowercase.
  217. {% endfilter %}
  218. .. note::
  219. The :tfilter:`escape` and :tfilter:`safe` filters are not acceptable
  220. arguments. Instead, use the :ttag:`autoescape` tag to manage autoescaping
  221. for blocks of template code.
  222. .. templatetag:: firstof
  223. ``firstof``
  224. -----------
  225. Outputs the first argument variable that is not "false" (i.e. exists, is not
  226. empty, is not a false boolean value, and is not a zero numeric value). Outputs
  227. nothing if all the passed variables are "false".
  228. Sample usage:
  229. .. code-block:: html+django
  230. {% firstof var1 var2 var3 %}
  231. This is equivalent to:
  232. .. code-block:: html+django
  233. {% if var1 %}
  234. {{ var1 }}
  235. {% elif var2 %}
  236. {{ var2 }}
  237. {% elif var3 %}
  238. {{ var3 }}
  239. {% endif %}
  240. You can also use a literal string as a fallback value in case all
  241. passed variables are False:
  242. .. code-block:: html+django
  243. {% firstof var1 var2 var3 "fallback value" %}
  244. This tag auto-escapes variable values. You can disable auto-escaping with:
  245. .. code-block:: html+django
  246. {% autoescape off %}
  247. {% firstof var1 var2 var3 "<strong>fallback value</strong>" %}
  248. {% endautoescape %}
  249. Or if only some variables should be escaped, you can use:
  250. .. code-block:: html+django
  251. {% firstof var1 var2|safe var3 "<strong>fallback value</strong>"|safe %}
  252. You can use the syntax ``{% firstof var1 var2 var3 as value %}`` to store the
  253. output inside a variable.
  254. .. templatetag:: for
  255. ``for``
  256. -------
  257. Loops over each item in an array, making the item available in a context
  258. variable. For example, to display a list of athletes provided in
  259. ``athlete_list``:
  260. .. code-block:: html+django
  261. <ul>
  262. {% for athlete in athlete_list %}
  263. <li>{{ athlete.name }}</li>
  264. {% endfor %}
  265. </ul>
  266. You can loop over a list in reverse by using
  267. ``{% for obj in list reversed %}``.
  268. If you need to loop over a list of lists, you can unpack the values
  269. in each sublist into individual variables. For example, if your context
  270. contains a list of (x,y) coordinates called ``points``, you could use the
  271. following to output the list of points:
  272. .. code-block:: html+django
  273. {% for x, y in points %}
  274. There is a point at {{ x }},{{ y }}
  275. {% endfor %}
  276. This can also be useful if you need to access the items in a dictionary.
  277. For example, if your context contained a dictionary ``data``, the following
  278. would display the keys and values of the dictionary:
  279. .. code-block:: html+django
  280. {% for key, value in data.items %}
  281. {{ key }}: {{ value }}
  282. {% endfor %}
  283. Keep in mind that for the dot operator, dictionary key lookup takes precedence
  284. over method lookup. Therefore if the ``data`` dictionary contains a key named
  285. ``'items'``, ``data.items`` will return ``data['items']`` instead of
  286. ``data.items()``. Avoid adding keys that are named like dictionary methods if
  287. you want to use those methods in a template (``items``, ``values``, ``keys``,
  288. etc.). Read more about the lookup order of the dot operator in the
  289. :ref:`documentation of template variables <template-variables>`.
  290. The for loop sets a number of variables available within the loop:
  291. ========================== ===============================================
  292. Variable Description
  293. ========================== ===============================================
  294. ``forloop.counter`` The current iteration of the loop (1-indexed)
  295. ``forloop.counter0`` The current iteration of the loop (0-indexed)
  296. ``forloop.revcounter`` The number of iterations from the end of the
  297. loop (1-indexed)
  298. ``forloop.revcounter0`` The number of iterations from the end of the
  299. loop (0-indexed)
  300. ``forloop.first`` True if this is the first time through the loop
  301. ``forloop.last`` True if this is the last time through the loop
  302. ``forloop.length`` The length of the loop
  303. ``forloop.parentloop`` For nested loops, this is the loop surrounding
  304. the current one
  305. ========================== ===============================================
  306. .. versionchanged:: 6.0
  307. The variable ``forloop.length`` was added.
  308. ``for`` ... ``empty``
  309. ---------------------
  310. The ``for`` tag can take an optional ``{% empty %}`` clause whose text is
  311. displayed if the given array is empty or could not be found:
  312. .. code-block:: html+django
  313. <ul>
  314. {% for athlete in athlete_list %}
  315. <li>{{ athlete.name }}</li>
  316. {% empty %}
  317. <li>Sorry, no athletes in this list.</li>
  318. {% endfor %}
  319. </ul>
  320. The above is equivalent to -- but shorter, cleaner, and possibly faster
  321. than -- the following:
  322. .. code-block:: html+django
  323. <ul>
  324. {% if athlete_list %}
  325. {% for athlete in athlete_list %}
  326. <li>{{ athlete.name }}</li>
  327. {% endfor %}
  328. {% else %}
  329. <li>Sorry, no athletes in this list.</li>
  330. {% endif %}
  331. </ul>
  332. .. templatetag:: if
  333. ``if``
  334. ------
  335. The ``{% if %}`` tag evaluates a variable, and if that variable is "true" (i.e.
  336. exists, is not empty, and is not a false boolean value) the contents of the
  337. block are output:
  338. .. code-block:: html+django
  339. {% if athlete_list %}
  340. Number of athletes: {{ athlete_list|length }}
  341. {% elif athlete_in_locker_room_list %}
  342. Athletes should be out of the locker room soon!
  343. {% else %}
  344. No athletes.
  345. {% endif %}
  346. In the above, if ``athlete_list`` is not empty, the number of athletes will be
  347. displayed by the ``{{ athlete_list|length }}`` variable.
  348. As you can see, the ``if`` tag may take one or several ``{% elif %}``
  349. clauses, as well as an ``{% else %}`` clause that will be displayed if all
  350. previous conditions fail. These clauses are optional.
  351. Boolean operators
  352. ~~~~~~~~~~~~~~~~~
  353. :ttag:`if` tags may use ``and``, ``or`` or ``not`` to test a number of
  354. variables or to negate a given variable:
  355. .. code-block:: html+django
  356. {% if athlete_list and coach_list %}
  357. Both athletes and coaches are available.
  358. {% endif %}
  359. {% if not athlete_list %}
  360. There are no athletes.
  361. {% endif %}
  362. {% if athlete_list or coach_list %}
  363. There are some athletes or some coaches.
  364. {% endif %}
  365. {% if not athlete_list or coach_list %}
  366. There are no athletes or there are some coaches.
  367. {% endif %}
  368. {% if athlete_list and not coach_list %}
  369. There are some athletes and absolutely no coaches.
  370. {% endif %}
  371. Use of both ``and`` and ``or`` clauses within the same tag is allowed, with
  372. ``and`` having higher precedence than ``or`` e.g.:
  373. .. code-block:: html+django
  374. {% if athlete_list and coach_list or cheerleader_list %}
  375. will be interpreted like::
  376. if (athlete_list and coach_list) or cheerleader_list:
  377. ...
  378. Use of actual parentheses in the :ttag:`if` tag is invalid syntax. If you need
  379. them to indicate precedence, you should use nested :ttag:`if` tags.
  380. :ttag:`if` tags may also use the operators ``==``, ``!=``, ``<``, ``>``,
  381. ``<=``, ``>=``, ``in``, ``not in``, ``is``, and ``is not`` which work as
  382. follows:
  383. ``==`` operator
  384. ^^^^^^^^^^^^^^^
  385. Equality. Example:
  386. .. code-block:: html+django
  387. {% if somevar == "x" %}
  388. This appears if variable somevar equals the string "x"
  389. {% endif %}
  390. ``!=`` operator
  391. ^^^^^^^^^^^^^^^
  392. Inequality. Example:
  393. .. code-block:: html+django
  394. {% if somevar != "x" %}
  395. This appears if variable somevar does not equal the string "x",
  396. or if somevar is not found in the context
  397. {% endif %}
  398. ``<`` operator
  399. ^^^^^^^^^^^^^^
  400. Less than. Example:
  401. .. code-block:: html+django
  402. {% if somevar < 100 %}
  403. This appears if variable somevar is less than 100.
  404. {% endif %}
  405. ``>`` operator
  406. ^^^^^^^^^^^^^^
  407. Greater than. Example:
  408. .. code-block:: html+django
  409. {% if somevar > 0 %}
  410. This appears if variable somevar is greater than 0.
  411. {% endif %}
  412. ``<=`` operator
  413. ^^^^^^^^^^^^^^^
  414. Less than or equal to. Example:
  415. .. code-block:: html+django
  416. {% if somevar <= 100 %}
  417. This appears if variable somevar is less than 100 or equal to 100.
  418. {% endif %}
  419. ``>=`` operator
  420. ^^^^^^^^^^^^^^^
  421. Greater than or equal to. Example:
  422. .. code-block:: html+django
  423. {% if somevar >= 1 %}
  424. This appears if variable somevar is greater than 1 or equal to 1.
  425. {% endif %}
  426. ``in`` operator
  427. ^^^^^^^^^^^^^^^
  428. Contained within. This operator is supported by many Python containers to test
  429. whether the given value is in the container. The following are some examples
  430. of how ``x in y`` will be interpreted:
  431. .. code-block:: html+django
  432. {% if "bc" in "abcdef" %}
  433. This appears since "bc" is a substring of "abcdef"
  434. {% endif %}
  435. {% if "hello" in greetings %}
  436. If greetings is a list or set, one element of which is the string
  437. "hello", this will appear.
  438. {% endif %}
  439. {% if user in users %}
  440. If users is a QuerySet, this will appear if user is an
  441. instance that belongs to the QuerySet.
  442. {% endif %}
  443. ``not in`` operator
  444. ^^^^^^^^^^^^^^^^^^^
  445. Not contained within. This is the negation of the ``in`` operator.
  446. ``is`` operator
  447. ^^^^^^^^^^^^^^^
  448. Object identity. Tests if two values are the same object. Example:
  449. .. code-block:: html+django
  450. {% if somevar is True %}
  451. This appears if and only if somevar is True.
  452. {% endif %}
  453. {% if somevar is None %}
  454. This appears if somevar is None, or if somevar is not found in the context.
  455. {% endif %}
  456. ``is not`` operator
  457. ^^^^^^^^^^^^^^^^^^^
  458. Negated object identity. Tests if two values are not the same object. This is
  459. the negation of the ``is`` operator. Example:
  460. .. code-block:: html+django
  461. {% if somevar is not True %}
  462. This appears if somevar is not True, or if somevar is not found in the
  463. context.
  464. {% endif %}
  465. {% if somevar is not None %}
  466. This appears if and only if somevar is not None.
  467. {% endif %}
  468. Filters
  469. ~~~~~~~
  470. You can also use filters in the :ttag:`if` expression. For example:
  471. .. code-block:: html+django
  472. {% if messages|length >= 100 %}
  473. You have lots of messages today!
  474. {% endif %}
  475. Complex expressions
  476. ~~~~~~~~~~~~~~~~~~~
  477. All of the above can be combined to form complex expressions. For such
  478. expressions, it can be important to know how the operators are grouped when the
  479. expression is evaluated - that is, the precedence rules. The precedence of the
  480. operators, from lowest to highest, is as follows:
  481. * ``or``
  482. * ``and``
  483. * ``not``
  484. * ``in``
  485. * ``==``, ``!=``, ``<``, ``>``, ``<=``, ``>=``
  486. (This follows Python exactly). So, for example, the following complex
  487. :ttag:`if` tag:
  488. .. code-block:: html+django
  489. {% if a == b or c == d and e %}
  490. ...will be interpreted as:
  491. .. code-block:: python
  492. (a == b) or ((c == d) and e)
  493. If you need different precedence, you will need to use nested :ttag:`if` tags.
  494. Sometimes that is better for clarity anyway, for the sake of those who do not
  495. know the precedence rules.
  496. The comparison operators cannot be 'chained' like in Python or in mathematical
  497. notation. For example, instead of using:
  498. .. code-block:: html+django
  499. {% if a > b > c %} (WRONG)
  500. you should use:
  501. .. code-block:: html+django
  502. {% if a > b and b > c %}
  503. .. templatetag:: ifchanged
  504. ``ifchanged``
  505. -------------
  506. Check if a value has changed from the last iteration of a loop.
  507. The ``{% ifchanged %}`` block tag is used within a loop. It has two possible
  508. uses.
  509. 1. Checks its own rendered contents against its previous state and only
  510. displays the content if it has changed. For example, this displays a list of
  511. days, only displaying the month if it changes:
  512. .. code-block:: html+django
  513. <h1>Archive for {{ year }}</h1>
  514. {% for date in days %}
  515. {% ifchanged %}<h3>{{ date|date:"F" }}</h3>{% endifchanged %}
  516. <a href="{{ date|date:"M/d"|lower }}/">{{ date|date:"j" }}</a>
  517. {% endfor %}
  518. 2. If given one or more variables, check whether any variable has changed.
  519. For example, the following shows the date every time it changes, while
  520. showing the hour if either the hour or the date has changed:
  521. .. code-block:: html+django
  522. {% for date in days %}
  523. {% ifchanged date.date %} {{ date.date }} {% endifchanged %}
  524. {% ifchanged date.hour date.date %}
  525. {{ date.hour }}
  526. {% endifchanged %}
  527. {% endfor %}
  528. The ``ifchanged`` tag can also take an optional ``{% else %}`` clause that
  529. will be displayed if the value has not changed:
  530. .. code-block:: html+django
  531. {% for match in matches %}
  532. <div style="background-color:
  533. {% ifchanged match.ballot_id %}
  534. {% cycle "red" "blue" %}
  535. {% else %}
  536. gray
  537. {% endifchanged %}
  538. ">{{ match }}</div>
  539. {% endfor %}
  540. .. templatetag:: include
  541. ``include``
  542. -----------
  543. Loads a template and renders it with the current context. This is a way of
  544. "including" other templates within a template.
  545. The template name can either be a variable or a hard-coded (quoted) string,
  546. in either single or double quotes.
  547. This example includes the contents of the template ``"foo/bar.html"``:
  548. .. code-block:: html+django
  549. {% include "foo/bar.html" %}
  550. Normally the template name is relative to the template loader's root directory.
  551. A string argument may also be a relative path starting with ``./`` or ``../``
  552. as described in the :ttag:`extends` tag.
  553. This example includes the contents of the template whose name is contained in
  554. the variable ``template_name``:
  555. .. code-block:: html+django
  556. {% include template_name %}
  557. The variable may also be any object with a ``render()`` method that accepts a
  558. context. This allows you to reference a compiled ``Template`` in your context.
  559. Additionally, the variable may be an iterable of template names, in which case
  560. the first that can be loaded will be used, as per
  561. :func:`~django.template.loader.select_template`.
  562. An included template is rendered within the context of the template that
  563. includes it. This example produces the output ``"Hello, John!"``:
  564. * Context: variable ``person`` is set to ``"John"`` and variable ``greeting``
  565. is set to ``"Hello"``.
  566. * Template:
  567. .. code-block:: html+django
  568. {% include "name_snippet.html" %}
  569. * The ``name_snippet.html`` template:
  570. .. code-block:: html+django
  571. {{ greeting }}, {{ person|default:"friend" }}!
  572. You can pass additional context to the template using keyword arguments:
  573. .. code-block:: html+django
  574. {% include "name_snippet.html" with person="Jane" greeting="Hello" %}
  575. If you want to render the context only with the variables provided (or even
  576. no variables at all), use the ``only`` option. No other variables are
  577. available to the included template:
  578. .. code-block:: html+django
  579. {% include "name_snippet.html" with greeting="Hi" only %}
  580. .. note::
  581. The :ttag:`include` tag should be considered as an implementation of
  582. "render this subtemplate and include the HTML", not as "parse this
  583. subtemplate and include its contents as if it were part of the parent".
  584. This means that there is no shared state between included templates --
  585. each include is a completely independent rendering process.
  586. Blocks are evaluated *before* they are included. This means that a template
  587. that includes blocks from another will contain blocks that have *already
  588. been evaluated and rendered* - not blocks that can be overridden by, for
  589. example, an extending template.
  590. .. templatetag:: load
  591. ``load``
  592. --------
  593. Loads a custom template tag set.
  594. For example, the following template would load all the tags and filters
  595. registered in ``somelibrary`` and ``otherlibrary`` located in package
  596. ``package``:
  597. .. code-block:: html+django
  598. {% load somelibrary package.otherlibrary %}
  599. You can also selectively load individual filters or tags from a library, using
  600. the ``from`` argument. In this example, the template tags/filters named ``foo``
  601. and ``bar`` will be loaded from ``somelibrary``:
  602. .. code-block:: html+django
  603. {% load foo bar from somelibrary %}
  604. See :doc:`Custom tag and filter libraries </howto/custom-template-tags>` for
  605. more information.
  606. .. templatetag:: lorem
  607. ``lorem``
  608. ---------
  609. Displays random "lorem ipsum" Latin text. This is useful for providing sample
  610. data in templates.
  611. Usage:
  612. .. code-block:: html+django
  613. {% lorem [count] [method] [random] %}
  614. The ``{% lorem %}`` tag can be used with zero, one, two or three arguments.
  615. The arguments are:
  616. =========== =============================================================
  617. Argument Description
  618. =========== =============================================================
  619. ``count`` A number (or variable) containing the number of paragraphs or
  620. words to generate (default is 1).
  621. ``method`` Either ``w`` for words, ``p`` for HTML paragraphs or ``b``
  622. for plain-text paragraph blocks (default is ``b``).
  623. ``random`` The word ``random``, which if given, does not use the common
  624. paragraph ("Lorem ipsum dolor sit amet...") when generating
  625. text.
  626. =========== =============================================================
  627. Examples:
  628. * ``{% lorem %}`` will output the common "lorem ipsum" paragraph.
  629. * ``{% lorem 3 p %}`` will output the common "lorem ipsum" paragraph
  630. and two random paragraphs each wrapped in HTML ``<p>`` tags.
  631. * ``{% lorem 2 w random %}`` will output two random Latin words.
  632. .. templatetag:: now
  633. ``now``
  634. -------
  635. Displays the current date and/or time, using a format according to the given
  636. string. Such string can contain format specifiers characters as described
  637. in the :tfilter:`date` filter section.
  638. Example:
  639. .. code-block:: html+django
  640. It is {% now "jS F Y H:i" %}
  641. Note that you can backslash-escape a format string if you want to use the
  642. "raw" value. In this example, both "o" and "f" are backslash-escaped, because
  643. otherwise each is a format string that displays the year and the time,
  644. respectively:
  645. .. code-block:: html+django
  646. It is the {% now "jS \o\f F" %}
  647. This would display as "It is the 4th of September".
  648. .. note::
  649. The format passed can also be one of the predefined ones
  650. :setting:`DATE_FORMAT`, :setting:`DATETIME_FORMAT`,
  651. :setting:`SHORT_DATE_FORMAT` or :setting:`SHORT_DATETIME_FORMAT`.
  652. The predefined formats may vary depending on the current locale and
  653. if :doc:`/topics/i18n/formatting` is enabled, e.g.:
  654. .. code-block:: html+django
  655. It is {% now "SHORT_DATETIME_FORMAT" %}
  656. You can also use the syntax ``{% now "Y" as current_year %}`` to store the
  657. output (as a string) inside a variable. This is useful if you want to use
  658. ``{% now %}`` inside a template tag like :ttag:`blocktranslate` for example:
  659. .. code-block:: html+django
  660. {% now "Y" as current_year %}
  661. {% blocktranslate %}Copyright {{ current_year }}{% endblocktranslate %}
  662. .. templatetag:: querystring
  663. ``querystring``
  664. ----------------
  665. Outputs a URL-encoded formatted query string based on the provided parameters.
  666. This tag requires a :class:`~django.http.QueryDict` instance, which defaults to
  667. :attr:`request.GET <django.http.HttpRequest.GET>` if none is provided.
  668. If the :class:`~django.http.QueryDict` is empty and no additional parameters
  669. are provided, an empty string is returned. Otherwise, the result includes a
  670. leading ``"?"``.
  671. .. admonition:: Using ``request.GET`` as default
  672. To use ``request.GET`` as the default ``QueryDict`` instance, the
  673. ``django.template.context_processors.request`` context processor should be
  674. enabled. If it's not enabled, you must either explicitly pass the
  675. ``request`` object into the template context, or provide a ``QueryDict``
  676. instance to this tag.
  677. Basic usage
  678. ~~~~~~~~~~~
  679. .. code-block:: html+django
  680. {% querystring %}
  681. Outputs the current query string verbatim. So if the query string is
  682. ``?color=green``, the output would be ``?color=green``.
  683. .. code-block:: html+django
  684. {% querystring size="M" %}
  685. Outputs the current query string with the addition of the ``size`` parameter.
  686. Following the previous example, the output would be ``?color=green&size=M``.
  687. Custom QueryDict
  688. ~~~~~~~~~~~~~~~~
  689. .. code-block:: html+django
  690. {% querystring my_query_dict %}
  691. You can provide a custom ``QueryDict`` to be used instead of ``request.GET``.
  692. So if ``my_query_dict`` is ``<QueryDict: {'color': ['blue']}>``, this outputs
  693. ``?color=blue``.
  694. Setting items
  695. ~~~~~~~~~~~~~
  696. .. code-block:: html+django
  697. {% querystring color="red" size="S" %}
  698. Adds or modifies parameters in the query string. Each keyword argument will be
  699. added to the query string, replacing any existing value for that key. For
  700. instance, if the current query string is ``?color=green``, the output will be
  701. ``?color=red&size=S``.
  702. Removing items
  703. ~~~~~~~~~~~~~~
  704. .. code-block:: html+django
  705. {% querystring color=None %}
  706. Passing ``None`` as the value removes the parameter from the query string. For
  707. example, if the current query string is ``?color=green&size=M``, the output
  708. will be ``?size=M``.
  709. Handling lists
  710. ~~~~~~~~~~~~~~
  711. .. code-block:: html+django
  712. {% querystring color=my_list %}
  713. If ``my_list`` is ``["red", "blue"]``, the output will be
  714. ``?color=red&color=blue``, preserving the list structure in the query string.
  715. Dynamic usage
  716. ~~~~~~~~~~~~~
  717. A common example of using this tag is to preserve the current query string when
  718. displaying a page of results, while adding a link to the next and previous
  719. pages of results. For example, if the paginator is currently on page 3, and the
  720. current query string is ``?color=blue&size=M&page=3``, the following code would
  721. output ``?color=blue&size=M&page=4``:
  722. .. code-block:: html+django
  723. {% querystring page=page.next_page_number %}
  724. You can also store the value in a variable. For example, if you need multiple
  725. links to the same page, define it as:
  726. .. code-block:: html+django
  727. {% querystring page=page.next_page_number as next_page %}
  728. .. templatetag:: regroup
  729. ``regroup``
  730. -----------
  731. Regroups a list of alike objects by a common attribute.
  732. This complex tag is best illustrated by way of an example: say that ``cities``
  733. is a list of cities represented by dictionaries containing ``"name"``,
  734. ``"population"``, and ``"country"`` keys:
  735. .. code-block:: python
  736. cities = [
  737. {"name": "Mumbai", "population": "19,000,000", "country": "India"},
  738. {"name": "Calcutta", "population": "15,000,000", "country": "India"},
  739. {"name": "New York", "population": "20,000,000", "country": "USA"},
  740. {"name": "Chicago", "population": "7,000,000", "country": "USA"},
  741. {"name": "Tokyo", "population": "33,000,000", "country": "Japan"},
  742. ]
  743. ...and you'd like to display a hierarchical list that is ordered by country,
  744. like this:
  745. * India
  746. * Mumbai: 19,000,000
  747. * Calcutta: 15,000,000
  748. * USA
  749. * New York: 20,000,000
  750. * Chicago: 7,000,000
  751. * Japan
  752. * Tokyo: 33,000,000
  753. You can use the ``{% regroup %}`` tag to group the list of cities by country.
  754. The following snippet of template code would accomplish this:
  755. .. code-block:: html+django
  756. {% regroup cities by country as country_list %}
  757. <ul>
  758. {% for country in country_list %}
  759. <li>{{ country.grouper }}
  760. <ul>
  761. {% for city in country.list %}
  762. <li>{{ city.name }}: {{ city.population }}</li>
  763. {% endfor %}
  764. </ul>
  765. </li>
  766. {% endfor %}
  767. </ul>
  768. Let's walk through this example. ``{% regroup %}`` takes three arguments: the
  769. list you want to regroup, the attribute to group by, and the name of the
  770. resulting list. Here, we're regrouping the ``cities`` list by the ``country``
  771. attribute and calling the result ``country_list``.
  772. ``{% regroup %}`` produces a list (in this case, ``country_list``) of
  773. **group objects**. Group objects are instances of
  774. :py:func:`~collections.namedtuple` with two fields:
  775. * ``grouper`` -- the item that was grouped by (e.g., the string "India" or
  776. "Japan").
  777. * ``list`` -- a list of all items in this group (e.g., a list of all cities
  778. with country='India').
  779. Because ``{% regroup %}`` produces :py:func:`~collections.namedtuple` objects,
  780. you can also write the previous example as:
  781. .. code-block:: html+django
  782. {% regroup cities by country as country_list %}
  783. <ul>
  784. {% for country, local_cities in country_list %}
  785. <li>{{ country }}
  786. <ul>
  787. {% for city in local_cities %}
  788. <li>{{ city.name }}: {{ city.population }}</li>
  789. {% endfor %}
  790. </ul>
  791. </li>
  792. {% endfor %}
  793. </ul>
  794. Note that ``{% regroup %}`` does not order its input! Our example relies on
  795. the fact that the ``cities`` list was ordered by ``country`` in the first place.
  796. If the ``cities`` list did *not* order its members by ``country``, the
  797. regrouping would naively display more than one group for a single country. For
  798. example, say the ``cities`` list was set to this (note that the countries are not
  799. grouped together):
  800. .. code-block:: python
  801. cities = [
  802. {"name": "Mumbai", "population": "19,000,000", "country": "India"},
  803. {"name": "New York", "population": "20,000,000", "country": "USA"},
  804. {"name": "Calcutta", "population": "15,000,000", "country": "India"},
  805. {"name": "Chicago", "population": "7,000,000", "country": "USA"},
  806. {"name": "Tokyo", "population": "33,000,000", "country": "Japan"},
  807. ]
  808. With this input for ``cities``, the example ``{% regroup %}`` template code
  809. above would result in the following output:
  810. * India
  811. * Mumbai: 19,000,000
  812. * USA
  813. * New York: 20,000,000
  814. * India
  815. * Calcutta: 15,000,000
  816. * USA
  817. * Chicago: 7,000,000
  818. * Japan
  819. * Tokyo: 33,000,000
  820. The easiest solution to this gotcha is to make sure in your view code that the
  821. data is ordered according to how you want to display it.
  822. Another solution is to sort the data in the template using the
  823. :tfilter:`dictsort` filter, if your data is in a list of dictionaries:
  824. .. code-block:: html+django
  825. {% regroup cities|dictsort:"country" by country as country_list %}
  826. Grouping on other properties
  827. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  828. Any valid template lookup is a legal grouping attribute for the regroup
  829. tag, including methods, attributes, dictionary keys and list items. For
  830. example, if the "country" field is a foreign key to a class with
  831. an attribute "description," you could use:
  832. .. code-block:: html+django
  833. {% regroup cities by country.description as country_list %}
  834. Or, if ``country`` is a field with ``choices``, it will have a
  835. :meth:`~django.db.models.Model.get_FOO_display` method available as an
  836. attribute, allowing you to group on the display string rather than the
  837. ``choices`` key:
  838. .. code-block:: html+django
  839. {% regroup cities by get_country_display as country_list %}
  840. ``{{ country.grouper }}`` will now display the value fields from the
  841. ``choices`` set rather than the keys.
  842. .. templatetag:: resetcycle
  843. ``resetcycle``
  844. --------------
  845. Resets a previous `cycle`_ so that it restarts from its first item at its next
  846. encounter. Without arguments, ``{% resetcycle %}`` will reset the last
  847. ``{% cycle %}`` defined in the template.
  848. Example usage:
  849. .. code-block:: html+django
  850. {% for coach in coach_list %}
  851. <h1>{{ coach.name }}</h1>
  852. {% for athlete in coach.athlete_set.all %}
  853. <p class="{% cycle 'odd' 'even' %}">{{ athlete.name }}</p>
  854. {% endfor %}
  855. {% resetcycle %}
  856. {% endfor %}
  857. This example would return this HTML:
  858. .. code-block:: html
  859. <h1>Gareth</h1>
  860. <p class="odd">Harry</p>
  861. <p class="even">John</p>
  862. <p class="odd">Nick</p>
  863. <h1>John</h1>
  864. <p class="odd">Andrea</p>
  865. <p class="even">Melissa</p>
  866. Notice how the first block ends with ``class="odd"`` and the new one starts
  867. with ``class="odd"``. Without the ``{% resetcycle %}`` tag, the second block
  868. would start with ``class="even"``.
  869. You can also reset named cycle tags:
  870. .. code-block:: html+django
  871. {% for item in list %}
  872. <p class="{% cycle 'odd' 'even' as stripe %} {% cycle 'major' 'minor' 'minor' 'minor' 'minor' as tick %}">
  873. {{ item.data }}
  874. </p>
  875. {% ifchanged item.category %}
  876. <h1>{{ item.category }}</h1>
  877. {% if not forloop.first %}{% resetcycle tick %}{% endif %}
  878. {% endifchanged %}
  879. {% endfor %}
  880. In this example, we have both the alternating odd/even rows and a "major" row
  881. every fifth row. Only the five-row cycle is reset when a category changes.
  882. .. templatetag:: spaceless
  883. ``spaceless``
  884. -------------
  885. Removes whitespace between HTML tags. This includes tab
  886. characters and newlines.
  887. Example usage:
  888. .. code-block:: html+django
  889. {% spaceless %}
  890. <p>
  891. <a href="foo/">Foo</a>
  892. </p>
  893. {% endspaceless %}
  894. This example would return this HTML:
  895. .. code-block:: html+django
  896. <p><a href="foo/">Foo</a></p>
  897. Only space between *tags* is removed -- not space between tags and text. In
  898. this example, the space around ``Hello`` won't be stripped:
  899. .. code-block:: html+django
  900. {% spaceless %}
  901. <strong>
  902. Hello
  903. </strong>
  904. {% endspaceless %}
  905. .. templatetag:: templatetag
  906. ``templatetag``
  907. ---------------
  908. Outputs one of the syntax characters used to compose template tags.
  909. The template system has no concept of "escaping" individual characters.
  910. However, you can use the ``{% templatetag %}`` tag to display one of the
  911. template tag character combinations.
  912. The argument tells which template bit to output:
  913. ================== =======
  914. Argument Outputs
  915. ================== =======
  916. ``openblock`` ``{%``
  917. ``closeblock`` ``%}``
  918. ``openvariable`` ``{{``
  919. ``closevariable`` ``}}``
  920. ``openbrace`` ``{``
  921. ``closebrace`` ``}``
  922. ``opencomment`` ``{#``
  923. ``closecomment`` ``#}``
  924. ================== =======
  925. Sample usage:
  926. .. code-block:: html+django
  927. The {% templatetag openblock %} characters open a block.
  928. See also the :ttag:`verbatim` tag for another way of including these
  929. characters.
  930. .. templatetag:: url
  931. ``url``
  932. -------
  933. Returns an absolute path reference (a URL without the domain name) matching a
  934. given view and optional parameters. Any special characters in the resulting
  935. path will be encoded using :func:`~django.utils.encoding.iri_to_uri`.
  936. This is a way to output links without violating the DRY principle by having to
  937. hard-code URLs in your templates:
  938. .. code-block:: html+django
  939. {% url 'some-url-name' v1 v2 %}
  940. The first argument is a :ref:`URL pattern name <naming-url-patterns>`. It can
  941. be a quoted literal or any other context variable. Additional arguments are
  942. optional and should be space-separated values that will be used as arguments in
  943. the URL. The example above shows passing positional arguments. Alternatively
  944. you may use keyword syntax:
  945. .. code-block:: html+django
  946. {% url 'some-url-name' arg1=v1 arg2=v2 %}
  947. Do not mix both positional and keyword syntax in a single call. All arguments
  948. required by the URLconf should be present.
  949. For example, suppose you have a view, ``app_views.client``, whose URLconf
  950. takes a client ID (here, ``client()`` is a method inside the views file
  951. ``app_views.py``). The URLconf line might look like this:
  952. .. code-block:: python
  953. path("client/<int:id>/", app_views.client, name="app-views-client")
  954. If this app's URLconf is included into the project's URLconf under a path
  955. such as this:
  956. .. code-block:: python
  957. path("clients/", include("project_name.app_name.urls"))
  958. ...then, in a template, you can create a link to this view like this:
  959. .. code-block:: html+django
  960. {% url 'app-views-client' client.id %}
  961. The template tag will output the string ``/clients/client/123/``.
  962. Note that if the URL you're reversing doesn't exist, you'll get an
  963. :exc:`~django.urls.NoReverseMatch` exception raised, which will cause your
  964. site to display an error page.
  965. If you'd like to retrieve a URL without displaying it, you can use a slightly
  966. different call:
  967. .. code-block:: html+django
  968. {% url 'some-url-name' arg arg2 as the_url %}
  969. <a href="{{ the_url }}">I'm linking to {{ the_url }}</a>
  970. The scope of the variable created by the ``as var`` syntax is the
  971. ``{% block %}`` in which the ``{% url %}`` tag appears.
  972. This ``{% url ... as var %}`` syntax will *not* cause an error if the view is
  973. missing. In practice you'll use this to link to views that are optional:
  974. .. code-block:: html+django
  975. {% url 'some-url-name' as the_url %}
  976. {% if the_url %}
  977. <a href="{{ the_url }}">Link to optional stuff</a>
  978. {% endif %}
  979. If you'd like to retrieve a namespaced URL, specify the fully qualified name:
  980. .. code-block:: html+django
  981. {% url 'myapp:view-name' %}
  982. This will follow the normal :ref:`namespaced URL resolution strategy
  983. <topics-http-reversing-url-namespaces>`, including using any hints provided
  984. by the context as to the current application.
  985. .. warning::
  986. Don't forget to put quotes around the URL pattern ``name``, otherwise the
  987. value will be interpreted as a context variable!
  988. .. templatetag:: verbatim
  989. ``verbatim``
  990. ------------
  991. Stops the template engine from rendering the contents of this block tag.
  992. A common use is to allow a JavaScript template layer that collides with
  993. Django's syntax. For example:
  994. .. code-block:: html+django
  995. {% verbatim %}
  996. {{if dying}}Still alive.{{/if}}
  997. {% endverbatim %}
  998. You can also designate a specific closing tag, allowing the use of
  999. ``{% endverbatim %}`` as part of the unrendered contents:
  1000. .. code-block:: html+django
  1001. {% verbatim myblock %}
  1002. Avoid template rendering via the {% verbatim %}{% endverbatim %} block.
  1003. {% endverbatim myblock %}
  1004. .. templatetag:: widthratio
  1005. ``widthratio``
  1006. --------------
  1007. For creating bar charts and such, this tag calculates the ratio of a given
  1008. value to a maximum value, and then applies that ratio to a constant.
  1009. For example:
  1010. .. code-block:: html+django
  1011. <img src="bar.png" alt="Bar"
  1012. height="10" width="{% widthratio this_value max_value max_width %}">
  1013. If ``this_value`` is 175, ``max_value`` is 200, and ``max_width`` is 100, the
  1014. image in the above example will be 88 pixels wide
  1015. (because 175/200 = .875; .875 * 100 = 87.5 which is rounded up to 88).
  1016. In some cases you might want to capture the result of ``widthratio`` in a
  1017. variable. It can be useful, for instance, in a :ttag:`blocktranslate` like this:
  1018. .. code-block:: html+django
  1019. {% widthratio this_value max_value max_width as width %}
  1020. {% blocktranslate %}The width is: {{ width }}{% endblocktranslate %}
  1021. .. templatetag:: with
  1022. ``with``
  1023. --------
  1024. Caches a complex variable under a simpler name. This is useful when accessing
  1025. an "expensive" method (e.g., one that hits the database) multiple times.
  1026. For example:
  1027. .. code-block:: html+django
  1028. {% with total=business.employees.count %}
  1029. {{ total }} employee{{ total|pluralize }}
  1030. {% endwith %}
  1031. The populated variable (in the example above, ``total``) is only available
  1032. between the ``{% with %}`` and ``{% endwith %}`` tags.
  1033. You can assign more than one context variable:
  1034. .. code-block:: html+django
  1035. {% with alpha=1 beta=2 %}
  1036. ...
  1037. {% endwith %}
  1038. .. note:: The previous more verbose format is still supported:
  1039. ``{% with business.employees.count as total %}``
  1040. .. _ref-templates-builtins-filters:
  1041. Built-in filter reference
  1042. =========================
  1043. .. templatefilter:: add
  1044. ``add``
  1045. -------
  1046. Adds the argument to the value.
  1047. For example:
  1048. .. code-block:: html+django
  1049. {{ value|add:"2" }}
  1050. If ``value`` is ``4``, then the output will be ``6``.
  1051. This filter will first try to coerce both values to integers. If this fails,
  1052. it'll attempt to add the values together anyway. This will work on some data
  1053. types (strings, list, etc.) and fail on others. If it fails, the result will
  1054. be an empty string.
  1055. For example, if we have:
  1056. .. code-block:: html+django
  1057. {{ first|add:second }}
  1058. and ``first`` is ``[1, 2, 3]`` and ``second`` is ``[4, 5, 6]``, then the
  1059. output will be ``[1, 2, 3, 4, 5, 6]``.
  1060. .. warning::
  1061. Strings that can be coerced to integers will be **summed**, not
  1062. concatenated, as in the first example above.
  1063. .. templatefilter:: addslashes
  1064. ``addslashes``
  1065. --------------
  1066. Adds slashes before quotes. Useful for escaping strings in CSV, for example.
  1067. For example:
  1068. .. code-block:: html+django
  1069. {{ value|addslashes }}
  1070. If ``value`` is ``"I'm using Django"``, the output will be
  1071. ``"I\'m using Django"``.
  1072. .. templatefilter:: capfirst
  1073. ``capfirst``
  1074. ------------
  1075. Capitalizes the first character of the value. If the first character is not
  1076. a letter, this filter has no effect.
  1077. For example:
  1078. .. code-block:: html+django
  1079. {{ value|capfirst }}
  1080. If ``value`` is ``"django"``, the output will be ``"Django"``.
  1081. .. templatefilter:: center
  1082. ``center``
  1083. ----------
  1084. Centers the value in a field of a given width.
  1085. For example:
  1086. .. code-block:: html+django
  1087. "{{ value|center:"15" }}"
  1088. If ``value`` is ``"Django"``, the output will be ``" Django "``.
  1089. .. templatefilter:: cut
  1090. ``cut``
  1091. -------
  1092. Removes all values of arg from the given string.
  1093. For example:
  1094. .. code-block:: html+django
  1095. {{ value|cut:" " }}
  1096. If ``value`` is ``"String with spaces"``, the output will be
  1097. ``"Stringwithspaces"``.
  1098. .. templatefilter:: date
  1099. ``date``
  1100. --------
  1101. Formats a date according to the given format.
  1102. Uses a similar format to PHP's `date()
  1103. <https://www.php.net/manual/en/function.date.php>`_ function with some
  1104. differences.
  1105. .. note::
  1106. These format characters are not used in Django outside of templates. They
  1107. were designed to be compatible with PHP to ease transitioning for designers.
  1108. .. _date-and-time-formatting-specifiers:
  1109. Available format strings:
  1110. ================ ======================================== =====================
  1111. Format character Description Example output
  1112. ================ ======================================== =====================
  1113. **Day**
  1114. ``d`` Day of the month, 2 digits with ``'01'`` to ``'31'``
  1115. leading zeros.
  1116. ``j`` Day of the month without leading ``'1'`` to ``'31'``
  1117. zeros.
  1118. ``D`` Day of the week, textual, 3 letters. ``'Fri'``
  1119. ``l`` Day of the week, textual, long. ``'Friday'``
  1120. ``S`` English ordinal suffix for day of the ``'st'``, ``'nd'``, ``'rd'`` or ``'th'``
  1121. month, 2 characters.
  1122. ``w`` Day of the week, digits without ``'0'`` (Sunday) to ``'6'`` (Saturday)
  1123. leading zeros.
  1124. ``z`` Day of the year. ``1`` to ``366``
  1125. **Week**
  1126. ``W`` ISO-8601 week number of year, with ``1``, ``53``
  1127. weeks starting on Monday.
  1128. **Month**
  1129. ``m`` Month, 2 digits with leading zeros. ``'01'`` to ``'12'``
  1130. ``n`` Month without leading zeros. ``'1'`` to ``'12'``
  1131. ``M`` Month, textual, 3 letters. ``'Jan'``
  1132. ``b`` Month, textual, 3 letters, lowercase. ``'jan'``
  1133. ``E`` Month, locale specific alternative
  1134. representation usually used for long
  1135. date representation. ``'listopada'`` (for Polish locale, as opposed to ``'Listopad'``)
  1136. ``F`` Month, textual, long. ``'January'``
  1137. ``N`` Month abbreviation in Associated Press ``'Jan.'``, ``'Feb.'``, ``'March'``, ``'May'``
  1138. style. Proprietary extension.
  1139. ``t`` Number of days in the given month. ``28`` to ``31``
  1140. **Year**
  1141. ``y`` Year, 2 digits with leading zeros. ``'00'`` to ``'99'``
  1142. ``Y`` Year, 4 digits with leading zeros. ``'0001'``, ..., ``'1999'``, ..., ``'9999'``
  1143. ``L`` Boolean for whether it's a leap year. ``True`` or ``False``
  1144. ``o`` ISO-8601 week-numbering year, ``'1999'``
  1145. corresponding to the ISO-8601 week
  1146. number (W) which uses leap weeks. See Y
  1147. for the more common year format.
  1148. **Time**
  1149. ``g`` Hour, 12-hour format without leading ``'1'`` to ``'12'``
  1150. zeros.
  1151. ``G`` Hour, 24-hour format without leading ``'0'`` to ``'23'``
  1152. zeros.
  1153. ``h`` Hour, 12-hour format. ``'01'`` to ``'12'``
  1154. ``H`` Hour, 24-hour format. ``'00'`` to ``'23'``
  1155. ``i`` Minutes. ``'00'`` to ``'59'``
  1156. ``s`` Seconds, 2 digits with leading zeros. ``'00'`` to ``'59'``
  1157. ``u`` Microseconds. ``000000`` to ``999999``
  1158. ``a`` ``'a.m.'`` or ``'p.m.'`` (Note that ``'a.m.'``
  1159. this is slightly different than PHP's
  1160. output, because this includes periods
  1161. to match Associated Press style.)
  1162. ``A`` ``'AM'`` or ``'PM'``. ``'AM'``
  1163. ``f`` Time, in 12-hour hours and minutes, ``'1'``, ``'1:30'``
  1164. with minutes left off if they're zero.
  1165. Proprietary extension.
  1166. ``P`` Time, in 12-hour hours, minutes and ``'1 a.m.'``, ``'1:30 p.m.'``, ``'midnight'``, ``'noon'``, ``'12:30 p.m.'``
  1167. 'a.m.'/'p.m.', with minutes left off
  1168. if they're zero and the special-case
  1169. strings 'midnight' and 'noon' if
  1170. appropriate. Proprietary extension.
  1171. **Timezone**
  1172. ``e`` Timezone name. Could be in any format,
  1173. or might return an empty string, ``''``, ``'GMT'``, ``'-500'``, ``'US/Eastern'``, etc.
  1174. depending on the datetime.
  1175. ``I`` Daylight saving time, whether it's in ``'1'`` or ``'0'``
  1176. effect or not.
  1177. ``O`` Difference to Greenwich time in hours. ``'+0200'``
  1178. ``T`` Time zone of this machine. ``'EST'``, ``'MDT'``
  1179. ``Z`` Time zone offset in seconds. The ``-43200`` to ``43200``
  1180. offset for timezones west of UTC is
  1181. always negative, and for those east of
  1182. UTC is always positive.
  1183. **Date/Time**
  1184. ``c`` ISO 8601 format. (Note: unlike other ``2008-01-02T10:30:00.000123+02:00``,
  1185. formatters, such as "Z", "O" or "r", or ``2008-01-02T10:30:00.000123`` if the datetime is naive
  1186. the "c" formatter will not add timezone
  1187. offset if value is a naive datetime
  1188. (see :class:`datetime.tzinfo`).
  1189. ``r`` :rfc:`RFC 5322 <5322#section-3.3>` ``'Thu, 21 Dec 2000 16:01:07 +0200'``
  1190. formatted date.
  1191. ``U`` Seconds since the Unix Epoch
  1192. (January 1 1970 00:00:00 UTC).
  1193. ================ ======================================== =====================
  1194. For example:
  1195. .. code-block:: html+django
  1196. {{ value|date:"D d M Y" }}
  1197. If ``value`` is a :py:class:`~datetime.datetime` object (e.g., the result of
  1198. ``datetime.datetime.now()``), the output will be the string
  1199. ``'Wed 09 Jan 2008'``.
  1200. The format passed can be one of the predefined ones :setting:`DATE_FORMAT`,
  1201. :setting:`DATETIME_FORMAT`, :setting:`SHORT_DATE_FORMAT` or
  1202. :setting:`SHORT_DATETIME_FORMAT`, or a custom format that uses the format
  1203. specifiers shown in the table above. Note that predefined formats may vary
  1204. depending on the current locale.
  1205. Assuming that :setting:`LANGUAGE_CODE` is, for example, ``"es"``, then for:
  1206. .. code-block:: html+django
  1207. {{ value|date:"SHORT_DATE_FORMAT" }}
  1208. the output would be the string ``"09/01/2008"`` (the ``"SHORT_DATE_FORMAT"``
  1209. format specifier for the ``es`` locale as shipped with Django is ``"d/m/Y"``).
  1210. When used without a format string, the ``DATE_FORMAT`` format specifier is
  1211. used. Assuming the same settings as the previous example:
  1212. .. code-block:: html+django
  1213. {{ value|date }}
  1214. outputs ``9 de Enero de 2008`` (the ``DATE_FORMAT`` format specifier for the
  1215. ``es`` locale is ``r'j \d\e F \d\e Y'``). Both "d" and "e" are
  1216. backslash-escaped, because otherwise each is a format string that displays the
  1217. day and the timezone name, respectively.
  1218. You can combine ``date`` with the :tfilter:`time` filter to render a full
  1219. representation of a ``datetime`` value. E.g.:
  1220. .. code-block:: html+django
  1221. {{ value|date:"D d M Y" }} {{ value|time:"H:i" }}
  1222. .. templatefilter:: default
  1223. ``default``
  1224. -----------
  1225. If value evaluates to ``False``, uses the given default. Otherwise, uses the
  1226. value.
  1227. For example:
  1228. .. code-block:: html+django
  1229. {{ value|default:"nothing" }}
  1230. If ``value`` is ``""`` (the empty string), the output will be ``nothing``.
  1231. .. templatefilter:: default_if_none
  1232. ``default_if_none``
  1233. -------------------
  1234. If (and only if) value is ``None``, uses the given default. Otherwise, uses the
  1235. value.
  1236. Note that if an empty string is given, the default value will *not* be used.
  1237. Use the :tfilter:`default` filter if you want to fallback for empty strings.
  1238. For example:
  1239. .. code-block:: html+django
  1240. {{ value|default_if_none:"nothing" }}
  1241. If ``value`` is ``None``, the output will be ``nothing``.
  1242. .. templatefilter:: dictsort
  1243. ``dictsort``
  1244. ------------
  1245. Takes a list of dictionaries and returns that list sorted by the key given in
  1246. the argument.
  1247. For example:
  1248. .. code-block:: html+django
  1249. {{ value|dictsort:"name" }}
  1250. If ``value`` is:
  1251. .. code-block:: python
  1252. [
  1253. {"name": "zed", "age": 19},
  1254. {"name": "amy", "age": 22},
  1255. {"name": "joe", "age": 31},
  1256. ]
  1257. then the output would be:
  1258. .. code-block:: python
  1259. [
  1260. {"name": "amy", "age": 22},
  1261. {"name": "joe", "age": 31},
  1262. {"name": "zed", "age": 19},
  1263. ]
  1264. You can also do more complicated things like:
  1265. .. code-block:: html+django
  1266. {% for book in books|dictsort:"author.age" %}
  1267. * {{ book.title }} ({{ book.author.name }})
  1268. {% endfor %}
  1269. If ``books`` is:
  1270. .. code-block:: python
  1271. [
  1272. {"title": "1984", "author": {"name": "George", "age": 45}},
  1273. {"title": "Timequake", "author": {"name": "Kurt", "age": 75}},
  1274. {"title": "Alice", "author": {"name": "Lewis", "age": 33}},
  1275. ]
  1276. then the output would be:
  1277. .. code-block:: html+django
  1278. * Alice (Lewis)
  1279. * 1984 (George)
  1280. * Timequake (Kurt)
  1281. ``dictsort`` can also order a list of lists (or any other object implementing
  1282. ``__getitem__()``) by elements at specified index. For example:
  1283. .. code-block:: html+django
  1284. {{ value|dictsort:0 }}
  1285. If ``value`` is:
  1286. .. code-block:: python
  1287. [
  1288. ("a", "42"),
  1289. ("c", "string"),
  1290. ("b", "foo"),
  1291. ]
  1292. then the output would be:
  1293. .. code-block:: python
  1294. [
  1295. ("a", "42"),
  1296. ("b", "foo"),
  1297. ("c", "string"),
  1298. ]
  1299. You must pass the index as an integer rather than a string. The following
  1300. produce empty output:
  1301. .. code-block:: html+django
  1302. {{ values|dictsort:"0" }}
  1303. Ordering by elements at specified index is not supported on dictionaries.
  1304. .. templatefilter:: dictsortreversed
  1305. ``dictsortreversed``
  1306. --------------------
  1307. Takes a list of dictionaries and returns that list sorted in reverse order by
  1308. the key given in the argument. This works exactly the same as the above filter,
  1309. but the returned value will be in reverse order.
  1310. .. templatefilter:: divisibleby
  1311. ``divisibleby``
  1312. ---------------
  1313. Returns ``True`` if the value is divisible by the argument.
  1314. For example:
  1315. .. code-block:: html+django
  1316. {{ value|divisibleby:"3" }}
  1317. If ``value`` is ``21``, the output would be ``True``.
  1318. .. templatefilter:: escape
  1319. ``escape``
  1320. ----------
  1321. Escapes a string's HTML. Specifically, it makes these replacements:
  1322. * ``<`` is converted to ``&lt;``
  1323. * ``>`` is converted to ``&gt;``
  1324. * ``'`` (single quote) is converted to ``&#x27;``
  1325. * ``"`` (double quote) is converted to ``&quot;``
  1326. * ``&`` is converted to ``&amp;``
  1327. Applying ``escape`` to a variable that would normally have auto-escaping
  1328. applied to the result will only result in one round of escaping being done. So
  1329. it is safe to use this function even in auto-escaping environments. If you want
  1330. multiple escaping passes to be applied, use the :tfilter:`force_escape` filter.
  1331. For example, you can apply ``escape`` to fields when :ttag:`autoescape` is off:
  1332. .. code-block:: html+django
  1333. {% autoescape off %}
  1334. {{ title|escape }}
  1335. {% endautoescape %}
  1336. .. admonition:: Chaining ``escape`` with other filters
  1337. As mentioned in the :ttag:`autoescape` section, when filters including
  1338. ``escape`` are chained together, it can result in unexpected outcomes if
  1339. preceding filters mark a potentially unsafe string as safe due to the lack
  1340. of escaping caused by :ttag:`autoescape` being ``off``.
  1341. In such cases, chaining ``escape`` would not reescape strings that have
  1342. already been marked as safe.
  1343. This is especially important when using filters that operate on sequences,
  1344. for example :tfilter:`join`. If you need to escape each element in a
  1345. sequence, use the dedicated :tfilter:`escapeseq` filter.
  1346. .. templatefilter:: escapejs
  1347. ``escapejs``
  1348. ------------
  1349. Escapes characters for use as a whole JavaScript string literal, within single
  1350. or double quotes, as below. This filter does not make the string safe for use
  1351. in *"JavaScript template literals"* (the JavaScript backtick syntax). Any other
  1352. uses not listed above are not supported. It is generally recommended that data
  1353. should be passed using HTML ``data-`` attributes, or the :tfilter:`json_script`
  1354. filter, rather than in embedded JavaScript.
  1355. For example:
  1356. .. code-block:: html+django
  1357. <script>
  1358. let myValue = '{{ value|escapejs }}'
  1359. .. templatefilter:: escapeseq
  1360. ``escapeseq``
  1361. -------------
  1362. Applies the :tfilter:`escape` filter to each element of a sequence. Useful in
  1363. conjunction with other filters that operate on sequences, such as
  1364. :tfilter:`join`. For example:
  1365. .. code-block:: html+django
  1366. {% autoescape off %}
  1367. {{ my_list|escapeseq|join:", " }}
  1368. {% endautoescape %}
  1369. .. templatefilter:: filesizeformat
  1370. ``filesizeformat``
  1371. ------------------
  1372. Formats the value like a 'human-readable' file size (i.e. ``'13 KB'``,
  1373. ``'4.1 MB'``, ``'102 bytes'``, etc.).
  1374. For example:
  1375. .. code-block:: html+django
  1376. {{ value|filesizeformat }}
  1377. If ``value`` is 123456789, the output would be ``117.7 MB``.
  1378. .. admonition:: File sizes and SI units
  1379. Strictly speaking, ``filesizeformat`` does not conform to the International
  1380. System of Units which recommends using KiB, MiB, GiB, etc. when byte sizes
  1381. are calculated in powers of 1024 (which is the case here). Instead, Django
  1382. uses traditional unit names (KB, MB, GB, etc.) corresponding to names that
  1383. are more commonly used.
  1384. .. templatefilter:: first
  1385. ``first``
  1386. ---------
  1387. Returns the first item in a list.
  1388. For example:
  1389. .. code-block:: html+django
  1390. {{ value|first }}
  1391. If ``value`` is the list ``['a', 'b', 'c']``, the output will be ``'a'``.
  1392. .. templatefilter:: floatformat
  1393. ``floatformat``
  1394. ---------------
  1395. When used without an argument, rounds a floating-point number to one decimal
  1396. place -- but only if there's a decimal part to be displayed. For example:
  1397. ============ =========================== ========
  1398. ``value`` Template Output
  1399. ============ =========================== ========
  1400. ``34.23234`` ``{{ value|floatformat }}`` ``34.2``
  1401. ``34.00000`` ``{{ value|floatformat }}`` ``34``
  1402. ``34.26000`` ``{{ value|floatformat }}`` ``34.3``
  1403. ============ =========================== ========
  1404. If used with a numeric integer argument, ``floatformat`` rounds a number to
  1405. that many decimal places. For example:
  1406. ============ ============================= ==========
  1407. ``value`` Template Output
  1408. ============ ============================= ==========
  1409. ``34.23234`` ``{{ value|floatformat:3 }}`` ``34.232``
  1410. ``34.00000`` ``{{ value|floatformat:3 }}`` ``34.000``
  1411. ``34.26000`` ``{{ value|floatformat:3 }}`` ``34.260``
  1412. ============ ============================= ==========
  1413. Particularly useful is passing 0 (zero) as the argument which will round the
  1414. float to the nearest integer.
  1415. ============ ================================ ==========
  1416. ``value`` Template Output
  1417. ============ ================================ ==========
  1418. ``34.23234`` ``{{ value|floatformat:"0" }}`` ``34``
  1419. ``34.00000`` ``{{ value|floatformat:"0" }}`` ``34``
  1420. ``39.56000`` ``{{ value|floatformat:"0" }}`` ``40``
  1421. ============ ================================ ==========
  1422. If the argument passed to ``floatformat`` is negative, it will round a number
  1423. to that many decimal places -- but only if there's a decimal part to be
  1424. displayed. For example:
  1425. ============ ================================ ==========
  1426. ``value`` Template Output
  1427. ============ ================================ ==========
  1428. ``34.23234`` ``{{ value|floatformat:"-3" }}`` ``34.232``
  1429. ``34.00000`` ``{{ value|floatformat:"-3" }}`` ``34``
  1430. ``34.26000`` ``{{ value|floatformat:"-3" }}`` ``34.260``
  1431. ============ ================================ ==========
  1432. If the argument passed to ``floatformat`` has the ``g`` suffix, it will force
  1433. grouping by the :setting:`THOUSAND_SEPARATOR` for the active locale. For
  1434. example, when the active locale is ``en`` (English):
  1435. ============ ================================= =============
  1436. ``value`` Template Output
  1437. ============ ================================= =============
  1438. ``34232.34`` ``{{ value|floatformat:"2g" }}`` ``34,232.34``
  1439. ``34232.06`` ``{{ value|floatformat:"g" }}`` ``34,232.1``
  1440. ``34232.00`` ``{{ value|floatformat:"-3g" }}`` ``34,232``
  1441. ============ ================================= =============
  1442. Output is always localized (independently of the :ttag:`{% localize off %}
  1443. <localize>` tag) unless the argument passed to ``floatformat`` has the ``u``
  1444. suffix, which will force disabling localization. For example, when the active
  1445. locale is ``pl`` (Polish):
  1446. ============ ================================= =============
  1447. ``value`` Template Output
  1448. ============ ================================= =============
  1449. ``34.23234`` ``{{ value|floatformat:"3" }}`` ``34,232``
  1450. ``34.23234`` ``{{ value|floatformat:"3u" }}`` ``34.232``
  1451. ============ ================================= =============
  1452. Using ``floatformat`` with no argument is equivalent to using ``floatformat``
  1453. with an argument of ``-1``.
  1454. .. templatefilter:: force_escape
  1455. ``force_escape``
  1456. ----------------
  1457. Applies HTML escaping to a string (see the :tfilter:`escape` filter for
  1458. details). This filter is applied *immediately* and returns a new, escaped
  1459. string. This is useful in the rare cases where you need multiple escaping or
  1460. want to apply other filters to the escaped results. Normally, you want to use
  1461. the :tfilter:`escape` filter.
  1462. For example, if you want to catch the ``<p>`` HTML elements created by
  1463. the :tfilter:`linebreaks` filter:
  1464. .. code-block:: html+django
  1465. {% autoescape off %}
  1466. {{ body|linebreaks|force_escape }}
  1467. {% endautoescape %}
  1468. .. templatefilter:: get_digit
  1469. ``get_digit``
  1470. -------------
  1471. Given a whole number, returns the requested digit, where 1 is the right-most
  1472. digit, 2 is the second-right-most digit, etc. Returns the original value for
  1473. invalid input (if input or argument is not an integer, or if argument is less
  1474. than 1). Otherwise, output is always an integer.
  1475. For example:
  1476. .. code-block:: html+django
  1477. {{ value|get_digit:"2" }}
  1478. If ``value`` is ``123456789``, the output will be ``8``.
  1479. .. templatefilter:: iriencode
  1480. ``iriencode``
  1481. -------------
  1482. Converts an IRI (Internationalized Resource Identifier) to a string that is
  1483. suitable for including in a URL. This is necessary if you're trying to use
  1484. strings containing non-ASCII characters in a URL.
  1485. It's safe to use this filter on a string that has already gone through the
  1486. :tfilter:`urlencode` filter.
  1487. For example:
  1488. .. code-block:: html+django
  1489. {{ value|iriencode }}
  1490. If ``value`` is ``"?test=I ♥ Django"``, the output will be
  1491. ``"?test=I%20%E2%99%A5%20Django"``.
  1492. .. templatefilter:: join
  1493. ``join``
  1494. --------
  1495. Joins a list with a string, like Python's ``str.join(list)``
  1496. For example:
  1497. .. code-block:: html+django
  1498. {{ value|join:" // " }}
  1499. If ``value`` is the list ``['a', 'b', 'c']``, the output will be the string
  1500. ``"a // b // c"``.
  1501. .. templatefilter:: json_script
  1502. ``json_script``
  1503. ---------------
  1504. Safely outputs a Python object as JSON, wrapped in a ``<script>`` tag, ready
  1505. for use with JavaScript.
  1506. **Argument:** The optional HTML "id" of the ``<script>`` tag.
  1507. For example:
  1508. .. code-block:: html+django
  1509. {{ value|json_script:"hello-data" }}
  1510. If ``value`` is the dictionary ``{'hello': 'world'}``, the output will be:
  1511. .. code-block:: html
  1512. <script id="hello-data" type="application/json">{"hello": "world"}</script>
  1513. The resulting data can be accessed in JavaScript like this:
  1514. .. code-block:: javascript
  1515. const value = JSON.parse(document.getElementById('hello-data').textContent);
  1516. XSS attacks are mitigated by escaping the characters "<", ">" and "&". For
  1517. example if ``value`` is ``{'hello': 'world</script>&amp;'}``, the output is:
  1518. .. code-block:: html
  1519. <script id="hello-data" type="application/json">{"hello": "world\\u003C/script\\u003E\\u0026amp;"}</script>
  1520. This is compatible with a strict Content Security Policy that prohibits in-page
  1521. script execution. It also maintains a clean separation between passive data and
  1522. executable code.
  1523. .. templatefilter:: last
  1524. ``last``
  1525. --------
  1526. Returns the last item in a list.
  1527. For example:
  1528. .. code-block:: html+django
  1529. {{ value|last }}
  1530. If ``value`` is the list ``['a', 'b', 'c', 'd']``, the output will be the
  1531. string ``"d"``.
  1532. .. templatefilter:: length
  1533. ``length``
  1534. ----------
  1535. Returns the length of the value. This works for both strings and lists.
  1536. For example:
  1537. .. code-block:: html+django
  1538. {{ value|length }}
  1539. If ``value`` is ``['a', 'b', 'c', 'd']`` or ``"abcd"``, the output will be
  1540. ``4``.
  1541. The filter returns ``0`` for an undefined variable.
  1542. .. templatefilter:: linebreaks
  1543. ``linebreaks``
  1544. --------------
  1545. Replaces line breaks in plain text with appropriate HTML; a single
  1546. newline becomes an HTML line break (``<br>``) and a new line
  1547. followed by a blank line becomes a paragraph break (``</p>``).
  1548. For example:
  1549. .. code-block:: html+django
  1550. {{ value|linebreaks }}
  1551. If ``value`` is ``Joel\nis a slug``, the output will be ``<p>Joel<br>is a
  1552. slug</p>``.
  1553. .. templatefilter:: linebreaksbr
  1554. ``linebreaksbr``
  1555. ----------------
  1556. Converts all newlines in a piece of plain text to HTML line breaks
  1557. (``<br>``).
  1558. For example:
  1559. .. code-block:: html+django
  1560. {{ value|linebreaksbr }}
  1561. If ``value`` is ``Joel\nis a slug``, the output will be ``Joel<br>is a
  1562. slug``.
  1563. .. templatefilter:: linenumbers
  1564. ``linenumbers``
  1565. ---------------
  1566. Displays text with line numbers.
  1567. For example:
  1568. .. code-block:: html+django
  1569. {{ value|linenumbers }}
  1570. If ``value`` is:
  1571. .. code-block:: html+django
  1572. one
  1573. two
  1574. three
  1575. the output will be:
  1576. .. code-block:: html+django
  1577. 1. one
  1578. 2. two
  1579. 3. three
  1580. .. templatefilter:: ljust
  1581. ``ljust``
  1582. ---------
  1583. Left-aligns the value in a field of a given width.
  1584. **Argument:** field size
  1585. For example:
  1586. .. code-block:: html+django
  1587. "{{ value|ljust:"10" }}"
  1588. If ``value`` is ``Django``, the output will be ``"Django "``.
  1589. .. templatefilter:: lower
  1590. ``lower``
  1591. ---------
  1592. Converts a string into all lowercase.
  1593. For example:
  1594. .. code-block:: html+django
  1595. {{ value|lower }}
  1596. If ``value`` is ``Totally LOVING this Album!``, the output will be
  1597. ``totally loving this album!``.
  1598. .. templatefilter:: make_list
  1599. ``make_list``
  1600. -------------
  1601. Returns the value turned into a list. For a string, it's a list of characters.
  1602. For an integer, the argument is cast to a string before creating a list.
  1603. For example:
  1604. .. code-block:: html+django
  1605. {{ value|make_list }}
  1606. If ``value`` is the string ``"Joel"``, the output would be the list
  1607. ``['J', 'o', 'e', 'l']``. If ``value`` is ``123``, the output will be the
  1608. list ``['1', '2', '3']``.
  1609. .. templatefilter:: phone2numeric
  1610. ``phone2numeric``
  1611. -----------------
  1612. Converts a phone number (possibly containing letters) to its numerical
  1613. equivalent.
  1614. The input doesn't have to be a valid phone number. This will happily convert
  1615. any string.
  1616. For example:
  1617. .. code-block:: html+django
  1618. {{ value|phone2numeric }}
  1619. If ``value`` is ``800-COLLECT``, the output will be ``800-2655328``.
  1620. .. templatefilter:: pluralize
  1621. ``pluralize``
  1622. -------------
  1623. Returns a plural suffix if the value is not ``1``, ``'1'``, or an object of
  1624. length 1. By default, this suffix is ``'s'``.
  1625. Example:
  1626. .. code-block:: html+django
  1627. You have {{ num_messages }} message{{ num_messages|pluralize }}.
  1628. If ``num_messages`` is ``1``, the output will be ``You have 1 message.``
  1629. If ``num_messages`` is ``2`` the output will be ``You have 2 messages.``
  1630. For words that require a suffix other than ``'s'``, you can provide an alternate
  1631. suffix as a parameter to the filter.
  1632. Example:
  1633. .. code-block:: html+django
  1634. You have {{ num_walruses }} walrus{{ num_walruses|pluralize:"es" }}.
  1635. For words that don't pluralize by simple suffix, you can specify both a
  1636. singular and plural suffix, separated by a comma.
  1637. Example:
  1638. .. code-block:: html+django
  1639. You have {{ num_cherries }} cherr{{ num_cherries|pluralize:"y,ies" }}.
  1640. .. note:: Use :ttag:`blocktranslate` to pluralize translated strings.
  1641. .. templatefilter:: pprint
  1642. ``pprint``
  1643. ----------
  1644. A wrapper around :func:`pprint.pprint` -- for debugging, really.
  1645. .. templatefilter:: random
  1646. ``random``
  1647. ----------
  1648. Returns a random item from the given list.
  1649. For example:
  1650. .. code-block:: html+django
  1651. {{ value|random }}
  1652. If ``value`` is the list ``['a', 'b', 'c', 'd']``, the output could be ``"b"``.
  1653. .. templatefilter:: rjust
  1654. ``rjust``
  1655. ---------
  1656. Right-aligns the value in a field of a given width.
  1657. **Argument:** field size
  1658. For example:
  1659. .. code-block:: html+django
  1660. "{{ value|rjust:"10" }}"
  1661. If ``value`` is ``Django``, the output will be ``" Django"``.
  1662. .. templatefilter:: safe
  1663. ``safe``
  1664. --------
  1665. Marks a string as not requiring further HTML escaping prior to output. When
  1666. autoescaping is off, this filter has no effect.
  1667. .. note::
  1668. If you are chaining filters, a filter applied after ``safe`` can
  1669. make the contents unsafe again. For example, the following code
  1670. prints the variable as is, unescaped:
  1671. .. code-block:: html+django
  1672. {{ var|safe|escape }}
  1673. .. templatefilter:: safeseq
  1674. ``safeseq``
  1675. -----------
  1676. Applies the :tfilter:`safe` filter to each element of a sequence. Useful in
  1677. conjunction with other filters that operate on sequences, such as
  1678. :tfilter:`join`. For example:
  1679. .. code-block:: html+django
  1680. {{ some_list|safeseq|join:", " }}
  1681. You couldn't use the :tfilter:`safe` filter directly in this case, as it would
  1682. first convert the variable into a string, rather than working with the
  1683. individual elements of the sequence.
  1684. .. templatefilter:: slice
  1685. ``slice``
  1686. ---------
  1687. Returns a slice of the list.
  1688. Uses the same syntax as Python's list slicing. See the `Python documentation
  1689. <https://docs.python.org/3/tutorial/introduction.html#lists>`_ for an
  1690. introduction.
  1691. Example:
  1692. .. code-block:: html+django
  1693. {{ some_list|slice:":2" }}
  1694. If ``some_list`` is ``['a', 'b', 'c']``, the output will be ``['a', 'b']``.
  1695. .. templatefilter:: slugify
  1696. ``slugify``
  1697. -----------
  1698. Converts to ASCII. Converts spaces to hyphens. Removes characters that aren't
  1699. alphanumerics, underscores, or hyphens. Converts to lowercase. Also strips
  1700. leading and trailing whitespace.
  1701. For example:
  1702. .. code-block:: html+django
  1703. {{ value|slugify }}
  1704. If ``value`` is ``"Joel is a slug"``, the output will be ``"joel-is-a-slug"``.
  1705. .. templatefilter:: stringformat
  1706. ``stringformat``
  1707. ----------------
  1708. Formats the variable according to the argument, a string formatting specifier.
  1709. This specifier uses the :ref:`old-string-formatting` syntax, with the exception
  1710. that the leading "%" is dropped.
  1711. For example:
  1712. .. code-block:: html+django
  1713. {{ value|stringformat:"E" }}
  1714. If ``value`` is ``10``, the output will be ``1.000000E+01``.
  1715. .. templatefilter:: striptags
  1716. ``striptags``
  1717. -------------
  1718. Makes all possible efforts to strip all [X]HTML tags.
  1719. For example:
  1720. .. code-block:: html+django
  1721. {{ value|striptags }}
  1722. If ``value`` is ``"<b>Joel</b> <button>is</button> a <span>slug</span>"``, the
  1723. output will be ``"Joel is a slug"``.
  1724. .. admonition:: No safety guarantee
  1725. Note that ``striptags`` doesn't give any guarantee about its output being
  1726. HTML safe, particularly with non valid HTML input. So **NEVER** apply the
  1727. ``safe`` filter to a ``striptags`` output. If you are looking for something
  1728. more robust, consider using a third-party HTML sanitizing tool.
  1729. .. templatefilter:: time
  1730. ``time``
  1731. --------
  1732. Formats a time according to the given format.
  1733. Given format can be the predefined one :setting:`TIME_FORMAT`, or a custom
  1734. format, same as the :tfilter:`date` filter. Note that the predefined format
  1735. is locale-dependent.
  1736. For example:
  1737. .. code-block:: html+django
  1738. {{ value|time:"H:i" }}
  1739. If ``value`` is equivalent to ``datetime.datetime.now()``, the output will be
  1740. the string ``"01:23"``.
  1741. Note that you can backslash-escape a format string if you want to use the
  1742. "raw" value. In this example, both "h" and "m" are backslash-escaped, because
  1743. otherwise each is a format string that displays the hour and the month,
  1744. respectively:
  1745. .. code-block:: html+django
  1746. {{ value|time:"H\h i\m" }}
  1747. This would display as "01h 23m".
  1748. Another example:
  1749. Assuming that :setting:`LANGUAGE_CODE` is, for example, ``"de"``, then for:
  1750. .. code-block:: html+django
  1751. {{ value|time:"TIME_FORMAT" }}
  1752. the output will be the string ``"01:23"`` (The ``"TIME_FORMAT"`` format
  1753. specifier for the ``de`` locale as shipped with Django is ``"H:i"``).
  1754. The ``time`` filter will only accept parameters in the format string that
  1755. relate to the time of day, not the date. If you need to format a ``date``
  1756. value, use the :tfilter:`date` filter instead (or along with :tfilter:`time` if
  1757. you need to render a full :py:class:`~datetime.datetime` value).
  1758. There is one exception the above rule: When passed a ``datetime`` value with
  1759. attached timezone information (a :ref:`time-zone-aware
  1760. <naive_vs_aware_datetimes>` ``datetime`` instance) the ``time`` filter will
  1761. accept the timezone-related :ref:`format specifiers
  1762. <date-and-time-formatting-specifiers>` ``'e'``, ``'O'`` , ``'T'`` and ``'Z'``.
  1763. When used without a format string, the ``TIME_FORMAT`` format specifier is
  1764. used:
  1765. .. code-block:: html+django
  1766. {{ value|time }}
  1767. is the same as:
  1768. .. code-block:: html+django
  1769. {{ value|time:"TIME_FORMAT" }}
  1770. .. templatefilter:: timesince
  1771. ``timesince``
  1772. -------------
  1773. Formats a date as the time since that date (e.g., "4 days, 6 hours").
  1774. Takes an optional argument that is a variable containing the date to use as
  1775. the comparison point (without the argument, the comparison point is *now*).
  1776. For example, if ``blog_date`` is a date instance representing midnight on 1
  1777. June 2006, and ``comment_date`` is a date instance for 08:00 on 1 June 2006,
  1778. then the following would return "8 hours":
  1779. .. code-block:: html+django
  1780. {{ blog_date|timesince:comment_date }}
  1781. Comparing offset-naive and offset-aware datetimes will return an empty string.
  1782. Minutes is the smallest unit used, and "0 minutes" will be returned for any
  1783. date that is in the future relative to the comparison point.
  1784. .. templatefilter:: timeuntil
  1785. ``timeuntil``
  1786. -------------
  1787. Similar to ``timesince``, except that it measures the time from now until the
  1788. given date or datetime. For example, if today is 1 June 2006 and
  1789. ``conference_date`` is a date instance holding 29 June 2006, then
  1790. ``{{ conference_date|timeuntil }}`` will return "4 weeks".
  1791. Takes an optional argument that is a variable containing the date to use as
  1792. the comparison point (instead of *now*). If ``from_date`` contains 22 June
  1793. 2006, then the following will return "1 week":
  1794. .. code-block:: html+django
  1795. {{ conference_date|timeuntil:from_date }}
  1796. Comparing offset-naive and offset-aware datetimes will return an empty string.
  1797. Minutes is the smallest unit used, and "0 minutes" will be returned for any
  1798. date that is in the past relative to the comparison point.
  1799. .. templatefilter:: title
  1800. ``title``
  1801. ---------
  1802. Converts a string into titlecase by making words start with an uppercase
  1803. character and the remaining characters lowercase. This tag makes no effort to
  1804. keep "trivial words" in lowercase.
  1805. For example:
  1806. .. code-block:: html+django
  1807. {{ value|title }}
  1808. If ``value`` is ``"my FIRST post"``, the output will be ``"My First Post"``.
  1809. .. templatefilter:: truncatechars
  1810. ``truncatechars``
  1811. -----------------
  1812. Truncates a string if it is longer than the specified number of characters.
  1813. Truncated strings will end with a translatable ellipsis character ("…").
  1814. **Argument:** Number of characters to truncate to
  1815. For example:
  1816. .. code-block:: html+django
  1817. {{ value|truncatechars:7 }}
  1818. If ``value`` is ``"Joel is a slug"``, the output will be ``"Joel i…"``.
  1819. .. templatefilter:: truncatechars_html
  1820. ``truncatechars_html``
  1821. ----------------------
  1822. Similar to :tfilter:`truncatechars`, except that it is aware of HTML tags. Any
  1823. tags that are opened in the string and not closed before the truncation point
  1824. are closed immediately after the truncation.
  1825. For example:
  1826. .. code-block:: html+django
  1827. {{ value|truncatechars_html:7 }}
  1828. If ``value`` is ``"<p>Joel is a slug</p>"``, the output will be
  1829. ``"<p>Joel i…</p>"``.
  1830. Newlines in the HTML content will be preserved.
  1831. .. admonition:: Size of input string
  1832. Processing large, potentially malformed HTML strings can be
  1833. resource-intensive and impact service performance. ``truncatechars_html``
  1834. limits input to the first five million characters.
  1835. .. templatefilter:: truncatewords
  1836. ``truncatewords``
  1837. -----------------
  1838. Truncates a string after a certain number of words.
  1839. **Argument:** Number of words to truncate after
  1840. For example:
  1841. .. code-block:: html+django
  1842. {{ value|truncatewords:2 }}
  1843. If ``value`` is ``"Joel is a slug"``, the output will be ``"Joel is …"``.
  1844. Newlines within the string will be removed.
  1845. .. templatefilter:: truncatewords_html
  1846. ``truncatewords_html``
  1847. ----------------------
  1848. Similar to :tfilter:`truncatewords`, except that it is aware of HTML tags. Any
  1849. tags that are opened in the string and not closed before the truncation point,
  1850. are closed immediately after the truncation.
  1851. This is less efficient than :tfilter:`truncatewords`, so should only be used
  1852. when it is being passed HTML text.
  1853. For example:
  1854. .. code-block:: html+django
  1855. {{ value|truncatewords_html:2 }}
  1856. If ``value`` is ``"<p>Joel is a slug</p>"``, the output will be
  1857. ``"<p>Joel is …</p>"``.
  1858. Newlines in the HTML content will be preserved.
  1859. .. admonition:: Size of input string
  1860. Processing large, potentially malformed HTML strings can be
  1861. resource-intensive and impact service performance. ``truncatewords_html``
  1862. limits input to the first five million characters.
  1863. .. templatefilter:: unordered_list
  1864. ``unordered_list``
  1865. ------------------
  1866. Recursively takes a self-nested list and returns an HTML unordered list --
  1867. WITHOUT opening and closing ``<ul>`` tags.
  1868. The list is assumed to be in the proper format. For example, if ``var``
  1869. contains ``['States', ['Kansas', ['Lawrence', 'Topeka'], 'Illinois']]``, then
  1870. ``{{ var|unordered_list }}`` would return:
  1871. .. code-block:: html+django
  1872. <li>States
  1873. <ul>
  1874. <li>Kansas
  1875. <ul>
  1876. <li>Lawrence</li>
  1877. <li>Topeka</li>
  1878. </ul>
  1879. </li>
  1880. <li>Illinois</li>
  1881. </ul>
  1882. </li>
  1883. .. templatefilter:: upper
  1884. ``upper``
  1885. ---------
  1886. Converts a string into all uppercase.
  1887. For example:
  1888. .. code-block:: html+django
  1889. {{ value|upper }}
  1890. If ``value`` is ``"Joel is a slug"``, the output will be ``"JOEL IS A SLUG"``.
  1891. .. templatefilter:: urlencode
  1892. ``urlencode``
  1893. -------------
  1894. Escapes a value for use in a URL.
  1895. For example:
  1896. .. code-block:: html+django
  1897. {{ value|urlencode }}
  1898. If ``value`` is ``"https://www.example.org/foo?a=b&c=d"``, the output will be
  1899. ``"https%3A//www.example.org/foo%3Fa%3Db%26c%3Dd"``.
  1900. An optional argument containing the characters which should not be escaped can
  1901. be provided.
  1902. If not provided, the '/' character is assumed safe. An empty string can be
  1903. provided when *all* characters should be escaped. For example:
  1904. .. code-block:: html+django
  1905. {{ value|urlencode:"" }}
  1906. If ``value`` is ``"https://www.example.org/"``, the output will be
  1907. ``"https%3A%2F%2Fwww.example.org%2F"``.
  1908. .. templatefilter:: urlize
  1909. ``urlize``
  1910. ----------
  1911. Converts URLs and email addresses in text into clickable links.
  1912. This template tag works on links prefixed with ``http://``, ``https://``, or
  1913. ``www.``. For example, ``https://djangocon.eu`` will get converted but
  1914. ``djangocon.eu`` won't.
  1915. It also supports domain-only links ending in one of the original top level
  1916. domains (``.com``, ``.edu``, ``.gov``, ``.int``, ``.mil``, ``.net``, and
  1917. ``.org``). For example, ``djangoproject.com`` gets converted.
  1918. Links can have trailing punctuation (periods, commas, close-parens) and leading
  1919. punctuation (opening parens), and ``urlize`` will still do the right thing.
  1920. Links generated by ``urlize`` have a ``rel="nofollow"`` attribute added
  1921. to them.
  1922. For example:
  1923. .. code-block:: html+django
  1924. {{ value|urlize }}
  1925. If ``value`` is ``"Check out www.djangoproject.com"``, the output will be
  1926. ``"Check out <a href="http://www.djangoproject.com"
  1927. rel="nofollow">www.djangoproject.com</a>"``.
  1928. In addition to web links, ``urlize`` also converts email addresses into
  1929. ``mailto:`` links. If ``value`` is
  1930. ``"Send questions to foo@example.com"``, the output will be
  1931. ``"Send questions to <a href="mailto:foo@example.com">foo@example.com</a>"``.
  1932. The ``urlize`` filter also takes an optional parameter ``autoescape``. If
  1933. ``autoescape`` is ``True``, the link text and URLs will be escaped using
  1934. Django's built-in :tfilter:`escape` filter. The default value for
  1935. ``autoescape`` is ``True``.
  1936. .. note::
  1937. If ``urlize`` is applied to text that already contains HTML markup, or to
  1938. email addresses that contain single quotes (``'``), things won't work as
  1939. expected. Apply this filter only to plain text.
  1940. .. templatefilter:: urlizetrunc
  1941. ``urlizetrunc``
  1942. ---------------
  1943. Converts URLs and email addresses into clickable links just like urlize_, but
  1944. truncates URLs longer than the given character limit.
  1945. **Argument:** Number of characters that link text should be truncated to,
  1946. including the ellipsis that's added if truncation is necessary.
  1947. For example:
  1948. .. code-block:: html+django
  1949. {{ value|urlizetrunc:15 }}
  1950. If ``value`` is ``"Check out www.djangoproject.com"``, the output would be
  1951. ``'Check out <a href="http://www.djangoproject.com"
  1952. rel="nofollow">www.djangoproj…</a>'``.
  1953. As with urlize_, this filter should only be applied to plain text.
  1954. .. templatefilter:: wordcount
  1955. ``wordcount``
  1956. -------------
  1957. Returns the number of words.
  1958. For example:
  1959. .. code-block:: html+django
  1960. {{ value|wordcount }}
  1961. If ``value`` is ``"Joel is a slug"``, the output will be ``4``.
  1962. .. templatefilter:: wordwrap
  1963. ``wordwrap``
  1964. ------------
  1965. Wraps words at specified line length.
  1966. **Argument:** number of characters at which to wrap the text
  1967. For example:
  1968. .. code-block:: html+django
  1969. {{ value|wordwrap:5 }}
  1970. If ``value`` is ``Joel is a slug``, the output would be:
  1971. .. code-block:: html+django
  1972. Joel
  1973. is a
  1974. slug
  1975. .. templatefilter:: yesno
  1976. ``yesno``
  1977. ---------
  1978. Maps values for ``True``, ``False``, and (optionally) ``None``, to the strings
  1979. "yes", "no", "maybe", or a custom mapping passed as a comma-separated list, and
  1980. returns one of those strings according to the value:
  1981. For example:
  1982. .. code-block:: html+django
  1983. {{ value|yesno:"yeah,no,maybe" }}
  1984. ========== ====================== ===========================================
  1985. Value Argument Outputs
  1986. ========== ====================== ===========================================
  1987. ``True`` ``yes``
  1988. ``True`` ``"yeah,no,maybe"`` ``yeah``
  1989. ``False`` ``"yeah,no,maybe"`` ``no``
  1990. ``None`` ``"yeah,no,maybe"`` ``maybe``
  1991. ``None`` ``"yeah,no"`` ``no`` (converts ``None`` to ``False``
  1992. if no mapping for ``None`` is given)
  1993. ========== ====================== ===========================================
  1994. Internationalization tags and filters
  1995. =====================================
  1996. Django provides template tags and filters to control each aspect of
  1997. :doc:`internationalization </topics/i18n/index>` in templates. They allow for
  1998. granular control of translations, formatting, and time zone conversions.
  1999. ``i18n``
  2000. --------
  2001. This library allows specifying translatable text in templates.
  2002. To enable it, set :setting:`USE_I18N` to ``True``, then load it with
  2003. ``{% load i18n %}``.
  2004. See :ref:`specifying-translation-strings-in-template-code`.
  2005. ``l10n``
  2006. --------
  2007. This library provides control over the localization of values in templates.
  2008. You only need to load the library using ``{% load l10n %}``.
  2009. See :ref:`topic-l10n-templates`.
  2010. ``tz``
  2011. ------
  2012. This library provides control over time zone conversions in templates.
  2013. Like ``l10n``, you only need to load the library using ``{% load tz %}``,
  2014. but you'll usually also set :setting:`USE_TZ` to ``True`` so that conversion
  2015. to local time happens by default.
  2016. See :ref:`time-zones-in-templates`.
  2017. Other tags and filters libraries
  2018. ================================
  2019. Django comes with a couple of other template-tag libraries that you have to
  2020. enable explicitly in your :setting:`INSTALLED_APPS` setting and enable in your
  2021. template with the :ttag:`{% load %}<load>` tag.
  2022. ``django.contrib.humanize``
  2023. ---------------------------
  2024. A set of Django template filters useful for adding a "human touch" to data. See
  2025. :doc:`/ref/contrib/humanize`.
  2026. ``static``
  2027. ----------
  2028. .. templatetag:: static
  2029. ``static``
  2030. ~~~~~~~~~~
  2031. To link to static files that are saved in :setting:`STATIC_ROOT` Django ships
  2032. with a :ttag:`static` template tag. If the :mod:`django.contrib.staticfiles`
  2033. app is installed, the tag will serve files using ``url()`` method of the
  2034. storage specified by ``staticfiles`` in :setting:`STORAGES`. For example:
  2035. .. code-block:: html+django
  2036. {% load static %}
  2037. <img src="{% static 'images/hi.jpg' %}" alt="Hi!">
  2038. It is also able to consume standard context variables, e.g. assuming a
  2039. ``user_stylesheet`` variable is passed to the template:
  2040. .. code-block:: html+django
  2041. {% load static %}
  2042. <link rel="stylesheet" href="{% static user_stylesheet %}" media="screen">
  2043. If you'd like to retrieve a static URL without displaying it, you can use a
  2044. slightly different call:
  2045. .. code-block:: html+django
  2046. {% load static %}
  2047. {% static "images/hi.jpg" as myphoto %}
  2048. <img src="{{ myphoto }}" alt="Hi!">
  2049. .. admonition:: Using Jinja2 templates?
  2050. See :class:`~django.template.backends.jinja2.Jinja2` for information on
  2051. using the ``static`` tag with Jinja2.
  2052. .. templatetag:: get_static_prefix
  2053. ``get_static_prefix``
  2054. ~~~~~~~~~~~~~~~~~~~~~
  2055. You should prefer the :ttag:`static` template tag, but if you need more control
  2056. over exactly where and how :setting:`STATIC_URL` is injected into the template,
  2057. you can use the :ttag:`get_static_prefix` template tag:
  2058. .. code-block:: html+django
  2059. {% load static %}
  2060. <img src="{% get_static_prefix %}images/hi.jpg" alt="Hi!">
  2061. There's also a second form you can use to avoid extra processing if you need
  2062. the value multiple times:
  2063. .. code-block:: html+django
  2064. {% load static %}
  2065. {% get_static_prefix as STATIC_PREFIX %}
  2066. <img src="{{ STATIC_PREFIX }}images/hi.jpg" alt="Hi!">
  2067. <img src="{{ STATIC_PREFIX }}images/hi2.jpg" alt="Hello!">
  2068. .. templatetag:: get_media_prefix
  2069. ``get_media_prefix``
  2070. ~~~~~~~~~~~~~~~~~~~~
  2071. Similar to the :ttag:`get_static_prefix`, ``get_media_prefix`` populates a
  2072. template variable with the media prefix :setting:`MEDIA_URL`, e.g.:
  2073. .. code-block:: html+django
  2074. {% load static %}
  2075. <body data-media-url="{% get_media_prefix %}">
  2076. By storing the value in a data attribute, we ensure it's escaped appropriately
  2077. if we want to use it in a JavaScript context.