builtins.txt 75 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. .. highlightlang:: html+django
  12. .. templatetag:: autoescape
  13. autoescape
  14. ^^^^^^^^^^
  15. Controls the current auto-escaping behavior. This tag takes either ``on`` or
  16. ``off`` as an argument and that determines whether auto-escaping is in effect
  17. inside the block. The block is closed with an ``endautoescape`` ending tag.
  18. When auto-escaping is in effect, all variable content has HTML escaping applied
  19. to it before placing the result into the output (but after any filters have
  20. been applied). This is equivalent to manually applying the :tfilter:`escape`
  21. filter to each variable.
  22. The only exceptions are variables that are already marked as "safe" from
  23. escaping, either by the code that populated the variable, or because it has had
  24. the :tfilter:`safe` or :tfilter:`escape` filters applied.
  25. Sample usage::
  26. {% autoescape on %}
  27. {{ body }}
  28. {% endautoescape %}
  29. .. templatetag:: block
  30. block
  31. ^^^^^
  32. Defines a block that can be overridden by child templates. See
  33. :ref:`Template inheritance <template-inheritance>` for more information.
  34. .. templatetag:: comment
  35. comment
  36. ^^^^^^^
  37. Ignores everything between ``{% comment %}`` and ``{% endcomment %}``.
  38. An optional note may be inserted in the first tag. For example, this is
  39. useful when commenting out code for documenting why the code was disabled.
  40. Sample usage::
  41. <p>Rendered text with {{ pub_date|date:"c" }}</p>
  42. {% comment "Optional note" %}
  43. <p>Commented out text with {{ create_date|date:"c" }}</p>
  44. {% endcomment %}
  45. ``comment`` tags cannot be nested.
  46. .. templatetag:: csrf_token
  47. csrf_token
  48. ^^^^^^^^^^
  49. This tag is used for CSRF protection, as described in the documentation for
  50. :doc:`Cross Site Request Forgeries </ref/csrf>`.
  51. .. templatetag:: cycle
  52. cycle
  53. ^^^^^
  54. Produces one of its arguments each time this tag is encountered. The first
  55. argument is produced on the first encounter, the second argument on the second
  56. encounter, and so forth. Once all arguments are exhausted, the tag cycles to
  57. the first argument and produces it again.
  58. This tag is particularly useful in a loop::
  59. {% for o in some_list %}
  60. <tr class="{% cycle 'row1' 'row2' %}">
  61. ...
  62. </tr>
  63. {% endfor %}
  64. The first iteration produces HTML that refers to class ``row1``, the second to
  65. ``row2``, the third to ``row1`` again, and so on for each iteration of the
  66. loop.
  67. You can use variables, too. For example, if you have two template variables,
  68. ``rowvalue1`` and ``rowvalue2``, you can alternate between their values like
  69. this::
  70. {% for o in some_list %}
  71. <tr class="{% cycle rowvalue1 rowvalue2 %}">
  72. ...
  73. </tr>
  74. {% endfor %}
  75. Variables included in the cycle will be escaped. You can disable auto-escaping
  76. with::
  77. {% for o in some_list %}
  78. <tr class="{% autoescape off %}{% cycle rowvalue1 rowvalue2 %}{% endautoescape %}">
  79. ...
  80. </tr>
  81. {% endfor %}
  82. You can mix variables and strings::
  83. {% for o in some_list %}
  84. <tr class="{% cycle 'row1' rowvalue2 'row3' %}">
  85. ...
  86. </tr>
  87. {% endfor %}
  88. In some cases you might want to refer to the current value of a cycle
  89. without advancing to the next value. To do this,
  90. just give the ``{% cycle %}`` tag a name, using "as", like this::
  91. {% cycle 'row1' 'row2' as rowcolors %}
  92. From then on, you can insert the current value of the cycle wherever you'd like
  93. in your template by referencing the cycle name as a context variable. If you
  94. want to move the cycle to the next value independently of the original
  95. ``cycle`` tag, you can use another ``cycle`` tag and specify the name of the
  96. variable. So, the following template::
  97. <tr>
  98. <td class="{% cycle 'row1' 'row2' as rowcolors %}">...</td>
  99. <td class="{{ rowcolors }}">...</td>
  100. </tr>
  101. <tr>
  102. <td class="{% cycle rowcolors %}">...</td>
  103. <td class="{{ rowcolors }}">...</td>
  104. </tr>
  105. would output::
  106. <tr>
  107. <td class="row1">...</td>
  108. <td class="row1">...</td>
  109. </tr>
  110. <tr>
  111. <td class="row2">...</td>
  112. <td class="row2">...</td>
  113. </tr>
  114. You can use any number of values in a ``cycle`` tag, separated by spaces.
  115. Values enclosed in single quotes (``'``) or double quotes (``"``) are treated
  116. as string literals, while values without quotes are treated as template
  117. variables.
  118. By default, when you use the ``as`` keyword with the cycle tag, the
  119. usage of ``{% cycle %}`` that initiates the cycle will itself produce
  120. the first value in the cycle. This could be a problem if you want to
  121. use the value in a nested loop or an included template. If you only want
  122. to declare the cycle but not produce the first value, you can add a
  123. ``silent`` keyword as the last keyword in the tag. For example::
  124. {% for obj in some_list %}
  125. {% cycle 'row1' 'row2' as rowcolors silent %}
  126. <tr class="{{ rowcolors }}">{% include "subtemplate.html" %}</tr>
  127. {% endfor %}
  128. This will output a list of ``<tr>`` elements with ``class``
  129. alternating between ``row1`` and ``row2``. The subtemplate will have
  130. access to ``rowcolors`` in its context and the value will match the class
  131. of the ``<tr>`` that encloses it. If the ``silent`` keyword were to be
  132. omitted, ``row1`` and ``row2`` would be emitted as normal text, outside the
  133. ``<tr>`` element.
  134. When the silent keyword is used on a cycle definition, the silence
  135. automatically applies to all subsequent uses of that specific cycle tag.
  136. The following template would output *nothing*, even though the second
  137. call to ``{% cycle %}`` doesn't specify ``silent``::
  138. {% cycle 'row1' 'row2' as rowcolors silent %}
  139. {% cycle rowcolors %}
  140. For backward compatibility, the ``{% cycle %}`` tag supports the much inferior
  141. old syntax from previous Django versions. You shouldn't use this in any new
  142. projects, but for the sake of the people who are still using it, here's what it
  143. looks like::
  144. {% cycle row1,row2,row3 %}
  145. In this syntax, each value gets interpreted as a literal string, and there's no
  146. way to specify variable values. Or literal commas. Or spaces. Did we mention
  147. you shouldn't use this syntax in any new projects?
  148. .. templatetag:: debug
  149. debug
  150. ^^^^^
  151. Outputs a whole load of debugging information, including the current context
  152. and imported modules.
  153. .. templatetag:: extends
  154. extends
  155. ^^^^^^^
  156. Signals that this template extends a parent template.
  157. This tag can be used in two ways:
  158. * ``{% extends "base.html" %}`` (with quotes) uses the literal value
  159. ``"base.html"`` as the name of the parent template to extend.
  160. * ``{% extends variable %}`` uses the value of ``variable``. If the variable
  161. evaluates to a string, Django will use that string as the name of the
  162. parent template. If the variable evaluates to a ``Template`` object,
  163. Django will use that object as the parent template.
  164. See :ref:`template-inheritance` for more information.
  165. .. templatetag:: filter
  166. filter
  167. ^^^^^^
  168. Filters the contents of the block through one or more filters. Multiple
  169. filters can be specified with pipes and filters can have arguments, just as
  170. in variable syntax.
  171. Note that the block includes *all* the text between the ``filter`` and
  172. ``endfilter`` tags.
  173. Sample usage::
  174. {% filter force_escape|lower %}
  175. This text will be HTML-escaped, and will appear in all lowercase.
  176. {% endfilter %}
  177. .. note::
  178. The :tfilter:`escape` and :tfilter:`safe` filters are not acceptable
  179. arguments. Instead, use the :ttag:`autoescape` tag to manage autoescaping
  180. for blocks of template code.
  181. .. templatetag:: firstof
  182. firstof
  183. ^^^^^^^
  184. Outputs the first argument variable that is not ``False``. Outputs nothing if
  185. all the passed variables are ``False``.
  186. Sample usage::
  187. {% firstof var1 var2 var3 %}
  188. This is equivalent to::
  189. {% if var1 %}
  190. {{ var1 }}
  191. {% elif var2 %}
  192. {{ var2 }}
  193. {% elif var3 %}
  194. {{ var3 }}
  195. {% endif %}
  196. You can also use a literal string as a fallback value in case all
  197. passed variables are False::
  198. {% firstof var1 var2 var3 "fallback value" %}
  199. This tag auto-escapes variable values. You can disable auto-escaping with::
  200. {% autoescape off %}
  201. {% firstof var1 var2 var3 "<strong>fallback value</strong>" %}
  202. {% endautoescape %}
  203. Or if only some variables should be escaped, you can use::
  204. {% firstof var1 var2|safe var3 "<strong>fallback value</strong>"|safe %}
  205. .. templatetag:: for
  206. for
  207. ^^^
  208. Loops over each item in an array, making the item available in a context
  209. variable. For example, to display a list of athletes provided in
  210. ``athlete_list``::
  211. <ul>
  212. {% for athlete in athlete_list %}
  213. <li>{{ athlete.name }}</li>
  214. {% endfor %}
  215. </ul>
  216. You can loop over a list in reverse by using
  217. ``{% for obj in list reversed %}``.
  218. If you need to loop over a list of lists, you can unpack the values
  219. in each sublist into individual variables. For example, if your context
  220. contains a list of (x,y) coordinates called ``points``, you could use the
  221. following to output the list of points::
  222. {% for x, y in points %}
  223. There is a point at {{ x }},{{ y }}
  224. {% endfor %}
  225. This can also be useful if you need to access the items in a dictionary.
  226. For example, if your context contained a dictionary ``data``, the following
  227. would display the keys and values of the dictionary::
  228. {% for key, value in data.items %}
  229. {{ key }}: {{ value }}
  230. {% endfor %}
  231. The for loop sets a number of variables available within the loop:
  232. ========================== ===============================================
  233. Variable Description
  234. ========================== ===============================================
  235. ``forloop.counter`` The current iteration of the loop (1-indexed)
  236. ``forloop.counter0`` The current iteration of the loop (0-indexed)
  237. ``forloop.revcounter`` The number of iterations from the end of the
  238. loop (1-indexed)
  239. ``forloop.revcounter0`` The number of iterations from the end of the
  240. loop (0-indexed)
  241. ``forloop.first`` True if this is the first time through the loop
  242. ``forloop.last`` True if this is the last time through the loop
  243. ``forloop.parentloop`` For nested loops, this is the loop surrounding
  244. the current one
  245. ========================== ===============================================
  246. for ... empty
  247. ^^^^^^^^^^^^^
  248. The ``for`` tag can take an optional ``{% empty %}`` clause whose text is
  249. displayed if the given array is empty or could not be found::
  250. <ul>
  251. {% for athlete in athlete_list %}
  252. <li>{{ athlete.name }}</li>
  253. {% empty %}
  254. <li>Sorry, no athletes in this list.</li>
  255. {% endfor %}
  256. </ul>
  257. The above is equivalent to -- but shorter, cleaner, and possibly faster
  258. than -- the following::
  259. <ul>
  260. {% if athlete_list %}
  261. {% for athlete in athlete_list %}
  262. <li>{{ athlete.name }}</li>
  263. {% endfor %}
  264. {% else %}
  265. <li>Sorry, no athletes in this list.</li>
  266. {% endif %}
  267. </ul>
  268. .. templatetag:: if
  269. if
  270. ^^
  271. The ``{% if %}`` tag evaluates a variable, and if that variable is "true" (i.e.
  272. exists, is not empty, and is not a false boolean value) the contents of the
  273. block are output::
  274. {% if athlete_list %}
  275. Number of athletes: {{ athlete_list|length }}
  276. {% elif athlete_in_locker_room_list %}
  277. Athletes should be out of the locker room soon!
  278. {% else %}
  279. No athletes.
  280. {% endif %}
  281. In the above, if ``athlete_list`` is not empty, the number of athletes will be
  282. displayed by the ``{{ athlete_list|length }}`` variable.
  283. As you can see, the ``if`` tag may take one or several ``{% elif %}``
  284. clauses, as well as an ``{% else %}`` clause that will be displayed if all
  285. previous conditions fail. These clauses are optional.
  286. Boolean operators
  287. ^^^^^^^^^^^^^^^^^
  288. :ttag:`if` tags may use ``and``, ``or`` or ``not`` to test a number of
  289. variables or to negate a given variable::
  290. {% if athlete_list and coach_list %}
  291. Both athletes and coaches are available.
  292. {% endif %}
  293. {% if not athlete_list %}
  294. There are no athletes.
  295. {% endif %}
  296. {% if athlete_list or coach_list %}
  297. There are some athletes or some coaches.
  298. {% endif %}
  299. {% if not athlete_list or coach_list %}
  300. There are no athletes or there are some coaches.
  301. {% endif %}
  302. {% if athlete_list and not coach_list %}
  303. There are some athletes and absolutely no coaches.
  304. {% endif %}
  305. Use of both ``and`` and ``or`` clauses within the same tag is allowed, with
  306. ``and`` having higher precedence than ``or`` e.g.::
  307. {% if athlete_list and coach_list or cheerleader_list %}
  308. will be interpreted like:
  309. .. code-block:: python
  310. if (athlete_list and coach_list) or cheerleader_list
  311. Use of actual parentheses in the :ttag:`if` tag is invalid syntax. If you need
  312. them to indicate precedence, you should use nested :ttag:`if` tags.
  313. :ttag:`if` tags may also use the operators ``==``, ``!=``, ``<``, ``>``,
  314. ``<=``, ``>=`` and ``in`` which work as follows:
  315. ``==`` operator
  316. ^^^^^^^^^^^^^^^
  317. Equality. Example::
  318. {% if somevar == "x" %}
  319. This appears if variable somevar equals the string "x"
  320. {% endif %}
  321. ``!=`` operator
  322. ^^^^^^^^^^^^^^^
  323. Inequality. Example::
  324. {% if somevar != "x" %}
  325. This appears if variable somevar does not equal the string "x",
  326. or if somevar is not found in the context
  327. {% endif %}
  328. ``<`` operator
  329. ^^^^^^^^^^^^^^
  330. Less than. Example::
  331. {% if somevar < 100 %}
  332. This appears if variable somevar is less than 100.
  333. {% endif %}
  334. ``>`` operator
  335. ^^^^^^^^^^^^^^
  336. Greater than. Example::
  337. {% if somevar > 0 %}
  338. This appears if variable somevar is greater than 0.
  339. {% endif %}
  340. ``<=`` operator
  341. ^^^^^^^^^^^^^^^
  342. Less than or equal to. Example::
  343. {% if somevar <= 100 %}
  344. This appears if variable somevar is less than 100 or equal to 100.
  345. {% endif %}
  346. ``>=`` operator
  347. ^^^^^^^^^^^^^^^
  348. Greater than or equal to. Example::
  349. {% if somevar >= 1 %}
  350. This appears if variable somevar is greater than 1 or equal to 1.
  351. {% endif %}
  352. ``in`` operator
  353. ^^^^^^^^^^^^^^^
  354. Contained within. This operator is supported by many Python containers to test
  355. whether the given value is in the container. The following are some examples
  356. of how ``x in y`` will be interpreted::
  357. {% if "bc" in "abcdef" %}
  358. This appears since "bc" is a substring of "abcdef"
  359. {% endif %}
  360. {% if "hello" in greetings %}
  361. If greetings is a list or set, one element of which is the string
  362. "hello", this will appear.
  363. {% endif %}
  364. {% if user in users %}
  365. If users is a QuerySet, this will appear if user is an
  366. instance that belongs to the QuerySet.
  367. {% endif %}
  368. ``not in`` operator
  369. ^^^^^^^^^^^^^^^^^^^
  370. Not contained within. This is the negation of the ``in`` operator.
  371. The comparison operators cannot be 'chained' like in Python or in mathematical
  372. notation. For example, instead of using::
  373. {% if a > b > c %} (WRONG)
  374. you should use::
  375. {% if a > b and b > c %}
  376. Filters
  377. ^^^^^^^
  378. You can also use filters in the :ttag:`if` expression. For example::
  379. {% if messages|length >= 100 %}
  380. You have lots of messages today!
  381. {% endif %}
  382. Complex expressions
  383. ^^^^^^^^^^^^^^^^^^^
  384. All of the above can be combined to form complex expressions. For such
  385. expressions, it can be important to know how the operators are grouped when the
  386. expression is evaluated - that is, the precedence rules. The precedence of the
  387. operators, from lowest to highest, is as follows:
  388. * ``or``
  389. * ``and``
  390. * ``not``
  391. * ``in``
  392. * ``==``, ``!=``, ``<``, ``>``, ``<=``, ``>=``
  393. (This follows Python exactly). So, for example, the following complex
  394. :ttag:`if` tag:
  395. .. code-block:: django
  396. {% if a == b or c == d and e %}
  397. ...will be interpreted as:
  398. .. code-block:: python
  399. (a == b) or ((c == d) and e)
  400. If you need different precedence, you will need to use nested :ttag:`if` tags.
  401. Sometimes that is better for clarity anyway, for the sake of those who do not
  402. know the precedence rules.
  403. .. templatetag:: ifchanged
  404. ifchanged
  405. ^^^^^^^^^
  406. Check if a value has changed from the last iteration of a loop.
  407. The ``{% ifchanged %}`` block tag is used within a loop. It has two possible
  408. uses.
  409. 1. Checks its own rendered contents against its previous state and only
  410. displays the content if it has changed. For example, this displays a list of
  411. days, only displaying the month if it changes::
  412. <h1>Archive for {{ year }}</h1>
  413. {% for date in days %}
  414. {% ifchanged %}<h3>{{ date|date:"F" }}</h3>{% endifchanged %}
  415. <a href="{{ date|date:"M/d"|lower }}/">{{ date|date:"j" }}</a>
  416. {% endfor %}
  417. 2. If given one or more variables, check whether any variable has changed.
  418. For example, the following shows the date every time it changes, while
  419. showing the hour if either the hour or the date has changed::
  420. {% for date in days %}
  421. {% ifchanged date.date %} {{ date.date }} {% endifchanged %}
  422. {% ifchanged date.hour date.date %}
  423. {{ date.hour }}
  424. {% endifchanged %}
  425. {% endfor %}
  426. The ``ifchanged`` tag can also take an optional ``{% else %}`` clause that
  427. will be displayed if the value has not changed::
  428. {% for match in matches %}
  429. <div style="background-color:
  430. {% ifchanged match.ballot_id %}
  431. {% cycle "red" "blue" %}
  432. {% else %}
  433. gray
  434. {% endifchanged %}
  435. ">{{ match }}</div>
  436. {% endfor %}
  437. .. templatetag:: ifequal
  438. ifequal
  439. ^^^^^^^
  440. Output the contents of the block if the two arguments equal each other.
  441. Example::
  442. {% ifequal user.pk comment.user_id %}
  443. ...
  444. {% endifequal %}
  445. As in the :ttag:`if` tag, an ``{% else %}`` clause is optional.
  446. The arguments can be hard-coded strings, so the following is valid::
  447. {% ifequal user.username "adrian" %}
  448. ...
  449. {% endifequal %}
  450. An alternative to the ``ifequal`` tag is to use the :ttag:`if` tag and the
  451. ``==`` operator.
  452. .. templatetag:: ifnotequal
  453. ifnotequal
  454. ^^^^^^^^^^
  455. Just like :ttag:`ifequal`, except it tests that the two arguments are not
  456. equal.
  457. An alternative to the ``ifnotequal`` tag is to use the :ttag:`if` tag and
  458. the ``!=`` operator.
  459. .. templatetag:: include
  460. include
  461. ^^^^^^^
  462. Loads a template and renders it with the current context. This is a way of
  463. "including" other templates within a template.
  464. The template name can either be a variable or a hard-coded (quoted) string,
  465. in either single or double quotes.
  466. This example includes the contents of the template ``"foo/bar.html"``::
  467. {% include "foo/bar.html" %}
  468. This example includes the contents of the template whose name is contained in
  469. the variable ``template_name``::
  470. {% include template_name %}
  471. .. versionchanged:: 1.7
  472. The variable may also be any object with a ``render()`` method that
  473. accepts a context. This allows you to reference a compiled ``Template`` in
  474. your context.
  475. An included template is rendered within the context of the template that
  476. includes it. This example produces the output ``"Hello, John"``:
  477. * Context: variable ``person`` is set to ``"john"``.
  478. * Template::
  479. {% include "name_snippet.html" %}
  480. * The ``name_snippet.html`` template::
  481. {{ greeting }}, {{ person|default:"friend" }}!
  482. You can pass additional context to the template using keyword arguments::
  483. {% include "name_snippet.html" with person="Jane" greeting="Hello" %}
  484. If you want to render the context only with the variables provided (or even
  485. no variables at all), use the ``only`` option. No other variables are
  486. available to the included template::
  487. {% include "name_snippet.html" with greeting="Hi" only %}
  488. .. note::
  489. The :ttag:`include` tag should be considered as an implementation of
  490. "render this subtemplate and include the HTML", not as "parse this
  491. subtemplate and include its contents as if it were part of the parent".
  492. This means that there is no shared state between included templates --
  493. each include is a completely independent rendering process.
  494. Blocks are evaluated *before* they are included. This means that a template
  495. that includes blocks from another will contain blocks that have *already
  496. been evaluated and rendered* - not blocks that can be overridden by, for
  497. example, an extending template.
  498. See also: :ttag:`{% ssi %}<ssi>`.
  499. .. templatetag:: load
  500. load
  501. ^^^^
  502. Loads a custom template tag set.
  503. For example, the following template would load all the tags and filters
  504. registered in ``somelibrary`` and ``otherlibrary`` located in package
  505. ``package``::
  506. {% load somelibrary package.otherlibrary %}
  507. You can also selectively load individual filters or tags from a library, using
  508. the ``from`` argument. In this example, the template tags/filters named ``foo``
  509. and ``bar`` will be loaded from ``somelibrary``::
  510. {% load foo bar from somelibrary %}
  511. See :doc:`Custom tag and filter libraries </howto/custom-template-tags>` for
  512. more information.
  513. .. templatetag:: lorem
  514. lorem
  515. ^^^^^
  516. .. versionadded:: 1.8
  517. The tag was previously located in :mod:`django.contrib.webdesign`.
  518. Displays random "lorem ipsum" Latin text. This is useful for providing sample
  519. data in templates.
  520. Usage::
  521. {% lorem [count] [method] [random] %}
  522. The ``{% lorem %}`` tag can be used with zero, one, two or three arguments.
  523. The arguments are:
  524. =========== =============================================================
  525. Argument Description
  526. =========== =============================================================
  527. ``count`` A number (or variable) containing the number of paragraphs or
  528. words to generate (default is 1).
  529. ``method`` Either ``w`` for words, ``p`` for HTML paragraphs or ``b``
  530. for plain-text paragraph blocks (default is ``b``).
  531. ``random`` The word ``random``, which if given, does not use the common
  532. paragraph ("Lorem ipsum dolor sit amet...") when generating
  533. text.
  534. =========== =============================================================
  535. Examples:
  536. * ``{% lorem %}`` will output the common "lorem ipsum" paragraph.
  537. * ``{% lorem 3 p %}`` will output the common "lorem ipsum" paragraph
  538. and two random paragraphs each wrapped in HTML ``<p>`` tags.
  539. * ``{% lorem 2 w random %}`` will output two random Latin words.
  540. .. templatetag:: now
  541. now
  542. ^^^
  543. Displays the current date and/or time, using a format according to the given
  544. string. Such string can contain format specifiers characters as described
  545. in the :tfilter:`date` filter section.
  546. Example::
  547. It is {% now "jS F Y H:i" %}
  548. Note that you can backslash-escape a format string if you want to use the
  549. "raw" value. In this example, both "o" and "f" are backslash-escaped, because
  550. otherwise each is a format string that displays the year and the time,
  551. respectively::
  552. It is the {% now "jS \o\f F" %}
  553. This would display as "It is the 4th of September".
  554. .. note::
  555. The format passed can also be one of the predefined ones
  556. :setting:`DATE_FORMAT`, :setting:`DATETIME_FORMAT`,
  557. :setting:`SHORT_DATE_FORMAT` or :setting:`SHORT_DATETIME_FORMAT`.
  558. The predefined formats may vary depending on the current locale and
  559. if :ref:`format-localization` is enabled, e.g.::
  560. It is {% now "SHORT_DATETIME_FORMAT" %}
  561. You can also use the syntax ``{% now "Y" as current_year %}`` to store the
  562. output inside a variable. This is useful if you want to use ``{% now %}``
  563. inside a template tag like :ttag:`blocktrans` for example::
  564. {% now "Y" as current_year %}
  565. {% blocktrans %}Copyright {{ current_year }}{% endblocktrans %}
  566. .. versionadded:: 1.8
  567. The ability to use the "as" syntax was added.
  568. .. templatetag:: regroup
  569. regroup
  570. ^^^^^^^
  571. Regroups a list of alike objects by a common attribute.
  572. This complex tag is best illustrated by way of an example: say that "places" is a list of cities represented by dictionaries containing ``"name"``, ``"population"``, and ``"country"`` keys:
  573. .. code-block:: python
  574. cities = [
  575. {'name': 'Mumbai', 'population': '19,000,000', 'country': 'India'},
  576. {'name': 'Calcutta', 'population': '15,000,000', 'country': 'India'},
  577. {'name': 'New York', 'population': '20,000,000', 'country': 'USA'},
  578. {'name': 'Chicago', 'population': '7,000,000', 'country': 'USA'},
  579. {'name': 'Tokyo', 'population': '33,000,000', 'country': 'Japan'},
  580. ]
  581. ...and you'd like to display a hierarchical list that is ordered by country, like this:
  582. * India
  583. * Mumbai: 19,000,000
  584. * Calcutta: 15,000,000
  585. * USA
  586. * New York: 20,000,000
  587. * Chicago: 7,000,000
  588. * Japan
  589. * Tokyo: 33,000,000
  590. You can use the ``{% regroup %}`` tag to group the list of cities by country.
  591. The following snippet of template code would accomplish this::
  592. {% regroup cities by country as country_list %}
  593. <ul>
  594. {% for country in country_list %}
  595. <li>{{ country.grouper }}
  596. <ul>
  597. {% for item in country.list %}
  598. <li>{{ item.name }}: {{ item.population }}</li>
  599. {% endfor %}
  600. </ul>
  601. </li>
  602. {% endfor %}
  603. </ul>
  604. Let's walk through this example. ``{% regroup %}`` takes three arguments: the
  605. list you want to regroup, the attribute to group by, and the name of the
  606. resulting list. Here, we're regrouping the ``cities`` list by the ``country``
  607. attribute and calling the result ``country_list``.
  608. ``{% regroup %}`` produces a list (in this case, ``country_list``) of
  609. **group objects**. Each group object has two attributes:
  610. * ``grouper`` -- the item that was grouped by (e.g., the string "India" or
  611. "Japan").
  612. * ``list`` -- a list of all items in this group (e.g., a list of all cities
  613. with country='India').
  614. Note that ``{% regroup %}`` does not order its input! Our example relies on
  615. the fact that the ``cities`` list was ordered by ``country`` in the first place.
  616. If the ``cities`` list did *not* order its members by ``country``, the
  617. regrouping would naively display more than one group for a single country. For
  618. example, say the ``cities`` list was set to this (note that the countries are not
  619. grouped together):
  620. .. code-block:: python
  621. cities = [
  622. {'name': 'Mumbai', 'population': '19,000,000', 'country': 'India'},
  623. {'name': 'New York', 'population': '20,000,000', 'country': 'USA'},
  624. {'name': 'Calcutta', 'population': '15,000,000', 'country': 'India'},
  625. {'name': 'Chicago', 'population': '7,000,000', 'country': 'USA'},
  626. {'name': 'Tokyo', 'population': '33,000,000', 'country': 'Japan'},
  627. ]
  628. With this input for ``cities``, the example ``{% regroup %}`` template code
  629. above would result in the following output:
  630. * India
  631. * Mumbai: 19,000,000
  632. * USA
  633. * New York: 20,000,000
  634. * India
  635. * Calcutta: 15,000,000
  636. * USA
  637. * Chicago: 7,000,000
  638. * Japan
  639. * Tokyo: 33,000,000
  640. The easiest solution to this gotcha is to make sure in your view code that the
  641. data is ordered according to how you want to display it.
  642. Another solution is to sort the data in the template using the
  643. :tfilter:`dictsort` filter, if your data is in a list of dictionaries::
  644. {% regroup cities|dictsort:"country" by country as country_list %}
  645. Grouping on other properties
  646. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  647. Any valid template lookup is a legal grouping attribute for the regroup
  648. tag, including methods, attributes, dictionary keys and list items. For
  649. example, if the "country" field is a foreign key to a class with
  650. an attribute "description," you could use::
  651. {% regroup cities by country.description as country_list %}
  652. Or, if ``country`` is a field with ``choices``, it will have a
  653. :meth:`~django.db.models.Model.get_FOO_display` method available as an
  654. attribute, allowing you to group on the display string rather than the
  655. ``choices`` key::
  656. {% regroup cities by get_country_display as country_list %}
  657. ``{{ country.grouper }}`` will now display the value fields from the
  658. ``choices`` set rather than the keys.
  659. .. templatetag:: spaceless
  660. spaceless
  661. ^^^^^^^^^
  662. Removes whitespace between HTML tags. This includes tab
  663. characters and newlines.
  664. Example usage::
  665. {% spaceless %}
  666. <p>
  667. <a href="foo/">Foo</a>
  668. </p>
  669. {% endspaceless %}
  670. This example would return this HTML::
  671. <p><a href="foo/">Foo</a></p>
  672. Only space between *tags* is removed -- not space between tags and text. In
  673. this example, the space around ``Hello`` won't be stripped::
  674. {% spaceless %}
  675. <strong>
  676. Hello
  677. </strong>
  678. {% endspaceless %}
  679. .. templatetag:: ssi
  680. ssi
  681. ^^^
  682. Outputs the contents of a given file into the page.
  683. Like a simple :ttag:`include` tag, ``{% ssi %}`` includes the contents of
  684. another file -- which must be specified using an absolute path -- in the
  685. current page::
  686. {% ssi '/home/html/ljworld.com/includes/right_generic.html' %}
  687. The first parameter of ``ssi`` can be a quoted literal or any other context
  688. variable.
  689. If the optional ``parsed`` parameter is given, the contents of the included
  690. file are evaluated as template code, within the current context::
  691. {% ssi '/home/html/ljworld.com/includes/right_generic.html' parsed %}
  692. Note that if you use ``{% ssi %}``, you'll need to define
  693. ``'allowed_include_roots'`` in the :setting:`OPTIONS <TEMPLATES-OPTIONS>` of
  694. your template engine, as a security measure.
  695. .. note::
  696. With the :ttag:`ssi` tag and the ``parsed`` parameter
  697. there is no shared state between files -- each include is a completely
  698. independent rendering process. This means it's not possible for example to
  699. define blocks or alter the context in the current page using the included
  700. file.
  701. See also: :ttag:`{% include %}<include>`.
  702. .. templatetag:: templatetag
  703. templatetag
  704. ^^^^^^^^^^^
  705. Outputs one of the syntax characters used to compose template tags.
  706. Since the template system has no concept of "escaping", to display one of the
  707. bits used in template tags, you must use the ``{% templatetag %}`` tag.
  708. The argument tells which template bit to output:
  709. ================== =======
  710. Argument Outputs
  711. ================== =======
  712. ``openblock`` ``{%``
  713. ``closeblock`` ``%}``
  714. ``openvariable`` ``{{``
  715. ``closevariable`` ``}}``
  716. ``openbrace`` ``{``
  717. ``closebrace`` ``}``
  718. ``opencomment`` ``{#``
  719. ``closecomment`` ``#}``
  720. ================== =======
  721. Sample usage::
  722. {% templatetag openblock %} url 'entry_list' {% templatetag closeblock %}
  723. .. templatetag:: url
  724. url
  725. ^^^
  726. Returns an absolute path reference (a URL without the domain name) matching a
  727. given view function and optional parameters. Any special characters in the
  728. resulting path will be encoded using :func:`~django.utils.encoding.iri_to_uri`.
  729. This is a way to output links without violating the DRY principle by having to
  730. hard-code URLs in your templates::
  731. {% url 'some-url-name' v1 v2 %}
  732. The first argument is a path to a view function in the format
  733. ``package.package.module.function``. It can be a quoted literal or any other
  734. context variable. Additional arguments are optional and
  735. should be space-separated values that will be used as arguments in the URL.
  736. The example above shows passing positional arguments. Alternatively you may
  737. use keyword syntax::
  738. {% url 'some-url-name' arg1=v1 arg2=v2 %}
  739. Do not mix both positional and keyword syntax in a single call. All arguments
  740. required by the URLconf should be present.
  741. For example, suppose you have a view, ``app_views.client``, whose URLconf
  742. takes a client ID (here, ``client()`` is a method inside the views file
  743. ``app_views.py``). The URLconf line might look like this:
  744. .. code-block:: python
  745. ('^client/([0-9]+)/$', 'app_views.client', name='app-views-client')
  746. If this app's URLconf is included into the project's URLconf under a path
  747. such as this:
  748. .. code-block:: python
  749. ('^clients/', include('project_name.app_name.urls'))
  750. ...then, in a template, you can create a link to this view like this::
  751. {% url 'app-views-client' client.id %}
  752. The template tag will output the string ``/clients/client/123/``.
  753. If you're using :ref:`named URL patterns <naming-url-patterns>`, you can
  754. refer to the name of the pattern in the ``url`` tag instead of using the
  755. path to the view.
  756. Note that if the URL you're reversing doesn't exist, you'll get an
  757. :exc:`~django.core.urlresolvers.NoReverseMatch` exception raised, which will
  758. cause your site to display an error page.
  759. If you'd like to retrieve a URL without displaying it, you can use a slightly
  760. different call::
  761. {% url 'some-url-name' arg arg2 as the_url %}
  762. <a href="{{ the_url }}">I'm linking to {{ the_url }}</a>
  763. The scope of the variable created by the ``as var`` syntax is the
  764. ``{% block %}`` in which the ``{% url %}`` tag appears.
  765. This ``{% url ... as var %}`` syntax will *not* cause an error if the view is
  766. missing. In practice you'll use this to link to views that are optional::
  767. {% url 'some-url-name' as the_url %}
  768. {% if the_url %}
  769. <a href="{{ the_url }}">Link to optional stuff</a>
  770. {% endif %}
  771. If you'd like to retrieve a namespaced URL, specify the fully qualified name::
  772. {% url 'myapp:view-name' %}
  773. This will follow the normal :ref:`namespaced URL resolution strategy
  774. <topics-http-reversing-url-namespaces>`, including using any hints provided
  775. by the context as to the current application.
  776. .. deprecated:: 1.8
  777. The dotted Python path syntax is deprecated and will be removed in
  778. Django 2.0::
  779. {% url 'path.to.some_view' v1 v2 %}
  780. .. warning::
  781. Don't forget to put quotes around the function path or pattern name,
  782. otherwise the value will be interpreted as a context variable!
  783. .. templatetag:: verbatim
  784. verbatim
  785. ^^^^^^^^
  786. Stops the template engine from rendering the contents of this block tag.
  787. A common use is to allow a Javascript template layer that collides with
  788. Django's syntax. For example::
  789. {% verbatim %}
  790. {{if dying}}Still alive.{{/if}}
  791. {% endverbatim %}
  792. You can also designate a specific closing tag, allowing the use of
  793. ``{% endverbatim %}`` as part of the unrendered contents::
  794. {% verbatim myblock %}
  795. Avoid template rendering via the {% verbatim %}{% endverbatim %} block.
  796. {% endverbatim myblock %}
  797. .. templatetag:: widthratio
  798. widthratio
  799. ^^^^^^^^^^
  800. For creating bar charts and such, this tag calculates the ratio of a given
  801. value to a maximum value, and then applies that ratio to a constant.
  802. For example::
  803. <img src="bar.png" alt="Bar"
  804. height="10" width="{% widthratio this_value max_value max_width %}" />
  805. If ``this_value`` is 175, ``max_value`` is 200, and ``max_width`` is 100, the
  806. image in the above example will be 88 pixels wide
  807. (because 175/200 = .875; .875 * 100 = 87.5 which is rounded up to 88).
  808. In some cases you might want to capture the result of ``widthratio`` in a
  809. variable. It can be useful, for instance, in a :ttag:`blocktrans` like this::
  810. {% widthratio this_value max_value max_width as width %}
  811. {% blocktrans %}The width is: {{ width }}{% endblocktrans %}
  812. .. versionchanged:: 1.7
  813. The ability to use "as" with this tag like in the example above was added.
  814. .. templatetag:: with
  815. with
  816. ^^^^
  817. Caches a complex variable under a simpler name. This is useful when accessing
  818. an "expensive" method (e.g., one that hits the database) multiple times.
  819. For example::
  820. {% with total=business.employees.count %}
  821. {{ total }} employee{{ total|pluralize }}
  822. {% endwith %}
  823. The populated variable (in the example above, ``total``) is only available
  824. between the ``{% with %}`` and ``{% endwith %}`` tags.
  825. You can assign more than one context variable::
  826. {% with alpha=1 beta=2 %}
  827. ...
  828. {% endwith %}
  829. .. note:: The previous more verbose format is still supported:
  830. ``{% with business.employees.count as total %}``
  831. .. _ref-templates-builtins-filters:
  832. Built-in filter reference
  833. -------------------------
  834. .. templatefilter:: add
  835. add
  836. ^^^
  837. Adds the argument to the value.
  838. For example::
  839. {{ value|add:"2" }}
  840. If ``value`` is ``4``, then the output will be ``6``.
  841. This filter will first try to coerce both values to integers. If this fails,
  842. it'll attempt to add the values together anyway. This will work on some data
  843. types (strings, list, etc.) and fail on others. If it fails, the result will
  844. be an empty string.
  845. For example, if we have::
  846. {{ first|add:second }}
  847. and ``first`` is ``[1, 2, 3]`` and ``second`` is ``[4, 5, 6]``, then the
  848. output will be ``[1, 2, 3, 4, 5, 6]``.
  849. .. warning::
  850. Strings that can be coerced to integers will be **summed**, not
  851. concatenated, as in the first example above.
  852. .. templatefilter:: addslashes
  853. addslashes
  854. ^^^^^^^^^^
  855. Adds slashes before quotes. Useful for escaping strings in CSV, for example.
  856. For example::
  857. {{ value|addslashes }}
  858. If ``value`` is ``"I'm using Django"``, the output will be
  859. ``"I\'m using Django"``.
  860. .. templatefilter:: capfirst
  861. capfirst
  862. ^^^^^^^^
  863. Capitalizes the first character of the value. If the first character is not
  864. a letter, this filter has no effect.
  865. For example::
  866. {{ value|capfirst }}
  867. If ``value`` is ``"django"``, the output will be ``"Django"``.
  868. .. templatefilter:: center
  869. center
  870. ^^^^^^
  871. Centers the value in a field of a given width.
  872. For example::
  873. "{{ value|center:"15" }}"
  874. If ``value`` is ``"Django"``, the output will be ``" Django "``.
  875. .. templatefilter:: cut
  876. cut
  877. ^^^
  878. Removes all values of arg from the given string.
  879. For example::
  880. {{ value|cut:" " }}
  881. If ``value`` is ``"String with spaces"``, the output will be
  882. ``"Stringwithspaces"``.
  883. .. templatefilter:: date
  884. date
  885. ^^^^
  886. Formats a date according to the given format.
  887. Uses a similar format as PHP's ``date()`` function (http://php.net/date)
  888. with some differences.
  889. .. note::
  890. These format characters are not used in Django outside of templates. They
  891. were designed to be compatible with PHP to ease transitioning for designers.
  892. .. _date-and-time-formatting-specifiers:
  893. Available format strings:
  894. ================ ======================================== =====================
  895. Format character Description Example output
  896. ================ ======================================== =====================
  897. a ``'a.m.'`` or ``'p.m.'`` (Note that ``'a.m.'``
  898. this is slightly different than PHP's
  899. output, because this includes periods
  900. to match Associated Press style.)
  901. A ``'AM'`` or ``'PM'``. ``'AM'``
  902. b Month, textual, 3 letters, lowercase. ``'jan'``
  903. B Not implemented.
  904. c ISO 8601 format. (Note: unlike others ``2008-01-02T10:30:00.000123+02:00``,
  905. formatters, such as "Z", "O" or "r", or ``2008-01-02T10:30:00.000123`` if the datetime is naive
  906. the "c" formatter will not add timezone
  907. offset if value is a naive datetime
  908. (see :class:`datetime.tzinfo`).
  909. d Day of the month, 2 digits with ``'01'`` to ``'31'``
  910. leading zeros.
  911. D Day of the week, textual, 3 letters. ``'Fri'``
  912. e Timezone name. Could be in any format,
  913. or might return an empty string, ``''``, ``'GMT'``, ``'-500'``, ``'US/Eastern'``, etc.
  914. depending on the datetime.
  915. E Month, locale specific alternative
  916. representation usually used for long
  917. date representation. ``'listopada'`` (for Polish locale, as opposed to ``'Listopad'``)
  918. f Time, in 12-hour hours and minutes, ``'1'``, ``'1:30'``
  919. with minutes left off if they're zero.
  920. Proprietary extension.
  921. F Month, textual, long. ``'January'``
  922. g Hour, 12-hour format without leading ``'1'`` to ``'12'``
  923. zeros.
  924. G Hour, 24-hour format without leading ``'0'`` to ``'23'``
  925. zeros.
  926. h Hour, 12-hour format. ``'01'`` to ``'12'``
  927. H Hour, 24-hour format. ``'00'`` to ``'23'``
  928. i Minutes. ``'00'`` to ``'59'``
  929. I Daylight Savings Time, whether it's ``'1'`` or ``'0'``
  930. in effect or not.
  931. j Day of the month without leading ``'1'`` to ``'31'``
  932. zeros.
  933. l Day of the week, textual, long. ``'Friday'``
  934. L Boolean for whether it's a leap year. ``True`` or ``False``
  935. m Month, 2 digits with leading zeros. ``'01'`` to ``'12'``
  936. M Month, textual, 3 letters. ``'Jan'``
  937. n Month without leading zeros. ``'1'`` to ``'12'``
  938. N Month abbreviation in Associated Press ``'Jan.'``, ``'Feb.'``, ``'March'``, ``'May'``
  939. style. Proprietary extension.
  940. o ISO-8601 week-numbering year, ``'1999'``
  941. corresponding to
  942. the ISO-8601 week number (W)
  943. O Difference to Greenwich time in hours. ``'+0200'``
  944. P Time, in 12-hour hours, minutes and ``'1 a.m.'``, ``'1:30 p.m.'``, ``'midnight'``, ``'noon'``, ``'12:30 p.m.'``
  945. 'a.m.'/'p.m.', with minutes left off
  946. if they're zero and the special-case
  947. strings 'midnight' and 'noon' if
  948. appropriate. Proprietary extension.
  949. r :rfc:`2822` formatted date. ``'Thu, 21 Dec 2000 16:01:07 +0200'``
  950. s Seconds, 2 digits with leading zeros. ``'00'`` to ``'59'``
  951. S English ordinal suffix for day of the ``'st'``, ``'nd'``, ``'rd'`` or ``'th'``
  952. month, 2 characters.
  953. t Number of days in the given month. ``28`` to ``31``
  954. T Time zone of this machine. ``'EST'``, ``'MDT'``
  955. u Microseconds. ``000000`` to ``999999``
  956. U Seconds since the Unix Epoch
  957. (January 1 1970 00:00:00 UTC).
  958. w Day of the week, digits without ``'0'`` (Sunday) to ``'6'`` (Saturday)
  959. leading zeros.
  960. W ISO-8601 week number of year, with ``1``, ``53``
  961. weeks starting on Monday.
  962. y Year, 2 digits. ``'99'``
  963. Y Year, 4 digits. ``'1999'``
  964. z Day of the year. ``0`` to ``365``
  965. Z Time zone offset in seconds. The ``-43200`` to ``43200``
  966. offset for timezones west of UTC is
  967. always negative, and for those east of
  968. UTC is always positive.
  969. ================ ======================================== =====================
  970. For example::
  971. {{ value|date:"D d M Y" }}
  972. If ``value`` is a :py:class:`~datetime.datetime` object (e.g., the result of
  973. ``datetime.datetime.now()``), the output will be the string
  974. ``'Wed 09 Jan 2008'``.
  975. The format passed can be one of the predefined ones :setting:`DATE_FORMAT`,
  976. :setting:`DATETIME_FORMAT`, :setting:`SHORT_DATE_FORMAT` or
  977. :setting:`SHORT_DATETIME_FORMAT`, or a custom format that uses the format
  978. specifiers shown in the table above. Note that predefined formats may vary
  979. depending on the current locale.
  980. Assuming that :setting:`USE_L10N` is ``True`` and :setting:`LANGUAGE_CODE` is,
  981. for example, ``"es"``, then for::
  982. {{ value|date:"SHORT_DATE_FORMAT" }}
  983. the output would be the string ``"09/01/2008"`` (the ``"SHORT_DATE_FORMAT"``
  984. format specifier for the ``es`` locale as shipped with Django is ``"d/m/Y"``).
  985. When used without a format string::
  986. {{ value|date }}
  987. ...the formatting string defined in the :setting:`DATE_FORMAT` setting will be
  988. used, without applying any localization.
  989. You can combine ``date`` with the :tfilter:`time` filter to render a full
  990. representation of a ``datetime`` value. E.g.::
  991. {{ value|date:"D d M Y" }} {{ value|time:"H:i" }}
  992. .. templatefilter:: default
  993. default
  994. ^^^^^^^
  995. If value evaluates to ``False``, uses the given default. Otherwise, uses the
  996. value.
  997. For example::
  998. {{ value|default:"nothing" }}
  999. If ``value`` is ``""`` (the empty string), the output will be ``nothing``.
  1000. .. templatefilter:: default_if_none
  1001. default_if_none
  1002. ^^^^^^^^^^^^^^^
  1003. If (and only if) value is ``None``, uses the given default. Otherwise, uses the
  1004. value.
  1005. Note that if an empty string is given, the default value will *not* be used.
  1006. Use the :tfilter:`default` filter if you want to fallback for empty strings.
  1007. For example::
  1008. {{ value|default_if_none:"nothing" }}
  1009. If ``value`` is ``None``, the output will be the string ``"nothing"``.
  1010. .. templatefilter:: dictsort
  1011. dictsort
  1012. ^^^^^^^^
  1013. Takes a list of dictionaries and returns that list sorted by the key given in
  1014. the argument.
  1015. For example::
  1016. {{ value|dictsort:"name" }}
  1017. If ``value`` is:
  1018. .. code-block:: python
  1019. [
  1020. {'name': 'zed', 'age': 19},
  1021. {'name': 'amy', 'age': 22},
  1022. {'name': 'joe', 'age': 31},
  1023. ]
  1024. then the output would be:
  1025. .. code-block:: python
  1026. [
  1027. {'name': 'amy', 'age': 22},
  1028. {'name': 'joe', 'age': 31},
  1029. {'name': 'zed', 'age': 19},
  1030. ]
  1031. You can also do more complicated things like::
  1032. {% for book in books|dictsort:"author.age" %}
  1033. * {{ book.title }} ({{ book.author.name }})
  1034. {% endfor %}
  1035. If ``books`` is:
  1036. .. code-block:: python
  1037. [
  1038. {'title': '1984', 'author': {'name': 'George', 'age': 45}},
  1039. {'title': 'Timequake', 'author': {'name': 'Kurt', 'age': 75}},
  1040. {'title': 'Alice', 'author': {'name': 'Lewis', 'age': 33}},
  1041. ]
  1042. then the output would be::
  1043. * Alice (Lewis)
  1044. * 1984 (George)
  1045. * Timequake (Kurt)
  1046. .. templatefilter:: dictsortreversed
  1047. dictsortreversed
  1048. ^^^^^^^^^^^^^^^^
  1049. Takes a list of dictionaries and returns that list sorted in reverse order by
  1050. the key given in the argument. This works exactly the same as the above filter,
  1051. but the returned value will be in reverse order.
  1052. .. templatefilter:: divisibleby
  1053. divisibleby
  1054. ^^^^^^^^^^^
  1055. Returns ``True`` if the value is divisible by the argument.
  1056. For example::
  1057. {{ value|divisibleby:"3" }}
  1058. If ``value`` is ``21``, the output would be ``True``.
  1059. .. templatefilter:: escape
  1060. escape
  1061. ^^^^^^
  1062. Escapes a string's HTML. Specifically, it makes these replacements:
  1063. * ``<`` is converted to ``&lt;``
  1064. * ``>`` is converted to ``&gt;``
  1065. * ``'`` (single quote) is converted to ``&#39;``
  1066. * ``"`` (double quote) is converted to ``&quot;``
  1067. * ``&`` is converted to ``&amp;``
  1068. The escaping is only applied when the string is output, so it does not matter
  1069. where in a chained sequence of filters you put ``escape``: it will always be
  1070. applied as though it were the last filter. If you want escaping to be applied
  1071. immediately, use the :tfilter:`force_escape` filter.
  1072. Applying ``escape`` to a variable that would normally have auto-escaping
  1073. applied to the result will only result in one round of escaping being done. So
  1074. it is safe to use this function even in auto-escaping environments. If you want
  1075. multiple escaping passes to be applied, use the :tfilter:`force_escape` filter.
  1076. For example, you can apply ``escape`` to fields when :ttag:`autoescape` is off::
  1077. {% autoescape off %}
  1078. {{ title|escape }}
  1079. {% endautoescape %}
  1080. .. templatefilter:: escapejs
  1081. escapejs
  1082. ^^^^^^^^
  1083. Escapes characters for use in JavaScript strings. This does *not* make the
  1084. string safe for use in HTML, but does protect you from syntax errors when using
  1085. templates to generate JavaScript/JSON.
  1086. For example::
  1087. {{ value|escapejs }}
  1088. If ``value`` is ``"testing\r\njavascript \'string" <b>escaping</b>"``,
  1089. the output will be ``"testing\\u000D\\u000Ajavascript \\u0027string\\u0022 \\u003Cb\\u003Eescaping\\u003C/b\\u003E"``.
  1090. .. templatefilter:: filesizeformat
  1091. filesizeformat
  1092. ^^^^^^^^^^^^^^
  1093. Formats the value like a 'human-readable' file size (i.e. ``'13 KB'``,
  1094. ``'4.1 MB'``, ``'102 bytes'``, etc).
  1095. For example::
  1096. {{ value|filesizeformat }}
  1097. If ``value`` is 123456789, the output would be ``117.7 MB``.
  1098. .. admonition:: File sizes and SI units
  1099. Strictly speaking, ``filesizeformat`` does not conform to the International
  1100. System of Units which recommends using KiB, MiB, GiB, etc. when byte sizes
  1101. are calculated in powers of 1024 (which is the case here). Instead, Django
  1102. uses traditional unit names (KB, MB, GB, etc.) corresponding to names that
  1103. are more commonly used.
  1104. .. templatefilter:: first
  1105. first
  1106. ^^^^^
  1107. Returns the first item in a list.
  1108. For example::
  1109. {{ value|first }}
  1110. If ``value`` is the list ``['a', 'b', 'c']``, the output will be ``'a'``.
  1111. .. templatefilter:: floatformat
  1112. floatformat
  1113. ^^^^^^^^^^^
  1114. When used without an argument, rounds a floating-point number to one decimal
  1115. place -- but only if there's a decimal part to be displayed. For example:
  1116. ============ =========================== ========
  1117. ``value`` Template Output
  1118. ============ =========================== ========
  1119. ``34.23234`` ``{{ value|floatformat }}`` ``34.2``
  1120. ``34.00000`` ``{{ value|floatformat }}`` ``34``
  1121. ``34.26000`` ``{{ value|floatformat }}`` ``34.3``
  1122. ============ =========================== ========
  1123. If used with a numeric integer argument, ``floatformat`` rounds a number to
  1124. that many decimal places. For example:
  1125. ============ ============================= ==========
  1126. ``value`` Template Output
  1127. ============ ============================= ==========
  1128. ``34.23234`` ``{{ value|floatformat:3 }}`` ``34.232``
  1129. ``34.00000`` ``{{ value|floatformat:3 }}`` ``34.000``
  1130. ``34.26000`` ``{{ value|floatformat:3 }}`` ``34.260``
  1131. ============ ============================= ==========
  1132. Particularly useful is passing 0 (zero) as the argument which will round the
  1133. float to the nearest integer.
  1134. ============ ================================ ==========
  1135. ``value`` Template Output
  1136. ============ ================================ ==========
  1137. ``34.23234`` ``{{ value|floatformat:"0" }}`` ``34``
  1138. ``34.00000`` ``{{ value|floatformat:"0" }}`` ``34``
  1139. ``39.56000`` ``{{ value|floatformat:"0" }}`` ``40``
  1140. ============ ================================ ==========
  1141. If the argument passed to ``floatformat`` is negative, it will round a number
  1142. to that many decimal places -- but only if there's a decimal part to be
  1143. displayed. For example:
  1144. ============ ================================ ==========
  1145. ``value`` Template Output
  1146. ============ ================================ ==========
  1147. ``34.23234`` ``{{ value|floatformat:"-3" }}`` ``34.232``
  1148. ``34.00000`` ``{{ value|floatformat:"-3" }}`` ``34``
  1149. ``34.26000`` ``{{ value|floatformat:"-3" }}`` ``34.260``
  1150. ============ ================================ ==========
  1151. Using ``floatformat`` with no argument is equivalent to using ``floatformat``
  1152. with an argument of ``-1``.
  1153. .. templatefilter:: force_escape
  1154. force_escape
  1155. ^^^^^^^^^^^^
  1156. Applies HTML escaping to a string (see the :tfilter:`escape` filter for
  1157. details). This filter is applied *immediately* and returns a new, escaped
  1158. string. This is useful in the rare cases where you need multiple escaping or
  1159. want to apply other filters to the escaped results. Normally, you want to use
  1160. the :tfilter:`escape` filter.
  1161. For example, if you want to catch the ``<p>`` HTML elements created by
  1162. the :tfilter:`linebreaks` filter::
  1163. {% autoescape off %}
  1164. {{ body|linebreaks|force_escape }}
  1165. {% endautoescape %}
  1166. .. templatefilter:: get_digit
  1167. get_digit
  1168. ^^^^^^^^^
  1169. Given a whole number, returns the requested digit, where 1 is the right-most
  1170. digit, 2 is the second-right-most digit, etc. Returns the original value for
  1171. invalid input (if input or argument is not an integer, or if argument is less
  1172. than 1). Otherwise, output is always an integer.
  1173. For example::
  1174. {{ value|get_digit:"2" }}
  1175. If ``value`` is ``123456789``, the output will be ``8``.
  1176. .. templatefilter:: iriencode
  1177. iriencode
  1178. ^^^^^^^^^
  1179. Converts an IRI (Internationalized Resource Identifier) to a string that is
  1180. suitable for including in a URL. This is necessary if you're trying to use
  1181. strings containing non-ASCII characters in a URL.
  1182. It's safe to use this filter on a string that has already gone through the
  1183. :tfilter:`urlencode` filter.
  1184. For example::
  1185. {{ value|iriencode }}
  1186. If ``value`` is ``"?test=1&me=2"``, the output will be ``"?test=1&amp;me=2"``.
  1187. .. templatefilter:: join
  1188. join
  1189. ^^^^
  1190. Joins a list with a string, like Python's ``str.join(list)``
  1191. For example::
  1192. {{ value|join:" // " }}
  1193. If ``value`` is the list ``['a', 'b', 'c']``, the output will be the string
  1194. ``"a // b // c"``.
  1195. .. templatefilter:: last
  1196. last
  1197. ^^^^
  1198. Returns the last item in a list.
  1199. For example::
  1200. {{ value|last }}
  1201. If ``value`` is the list ``['a', 'b', 'c', 'd']``, the output will be the
  1202. string ``"d"``.
  1203. .. templatefilter:: length
  1204. length
  1205. ^^^^^^
  1206. Returns the length of the value. This works for both strings and lists.
  1207. For example::
  1208. {{ value|length }}
  1209. If ``value`` is ``['a', 'b', 'c', 'd']`` or ``"abcd"``, the output will be
  1210. ``4``.
  1211. .. versionchanged:: 1.8
  1212. The filter returns ``0`` for an undefined variable. Previously, it returned
  1213. an empty string.
  1214. .. templatefilter:: length_is
  1215. length_is
  1216. ^^^^^^^^^
  1217. Returns ``True`` if the value's length is the argument, or ``False`` otherwise.
  1218. For example::
  1219. {{ value|length_is:"4" }}
  1220. If ``value`` is ``['a', 'b', 'c', 'd']`` or ``"abcd"``, the output will be
  1221. ``True``.
  1222. .. templatefilter:: linebreaks
  1223. linebreaks
  1224. ^^^^^^^^^^
  1225. Replaces line breaks in plain text with appropriate HTML; a single
  1226. newline becomes an HTML line break (``<br />``) and a new line
  1227. followed by a blank line becomes a paragraph break (``</p>``).
  1228. For example::
  1229. {{ value|linebreaks }}
  1230. If ``value`` is ``Joel\nis a slug``, the output will be ``<p>Joel<br />is a
  1231. slug</p>``.
  1232. .. templatefilter:: linebreaksbr
  1233. linebreaksbr
  1234. ^^^^^^^^^^^^
  1235. Converts all newlines in a piece of plain text to HTML line breaks
  1236. (``<br />``).
  1237. For example::
  1238. {{ value|linebreaksbr }}
  1239. If ``value`` is ``Joel\nis a slug``, the output will be ``Joel<br />is a
  1240. slug``.
  1241. .. templatefilter:: linenumbers
  1242. linenumbers
  1243. ^^^^^^^^^^^
  1244. Displays text with line numbers.
  1245. For example::
  1246. {{ value|linenumbers }}
  1247. If ``value`` is::
  1248. one
  1249. two
  1250. three
  1251. the output will be::
  1252. 1. one
  1253. 2. two
  1254. 3. three
  1255. .. templatefilter:: ljust
  1256. ljust
  1257. ^^^^^
  1258. Left-aligns the value in a field of a given width.
  1259. **Argument:** field size
  1260. For example::
  1261. "{{ value|ljust:"10" }}"
  1262. If ``value`` is ``Django``, the output will be ``"Django "``.
  1263. .. templatefilter:: lower
  1264. lower
  1265. ^^^^^
  1266. Converts a string into all lowercase.
  1267. For example::
  1268. {{ value|lower }}
  1269. If ``value`` is ``Still MAD At Yoko``, the output will be
  1270. ``still mad at yoko``.
  1271. .. templatefilter:: make_list
  1272. make_list
  1273. ^^^^^^^^^
  1274. Returns the value turned into a list. For a string, it's a list of characters.
  1275. For an integer, the argument is cast into an unicode string before creating a
  1276. list.
  1277. For example::
  1278. {{ value|make_list }}
  1279. If ``value`` is the string ``"Joel"``, the output would be the list
  1280. ``['J', 'o', 'e', 'l']``. If ``value`` is ``123``, the output will be the
  1281. list ``['1', '2', '3']``.
  1282. .. templatefilter:: phone2numeric
  1283. phone2numeric
  1284. ^^^^^^^^^^^^^
  1285. Converts a phone number (possibly containing letters) to its numerical
  1286. equivalent.
  1287. The input doesn't have to be a valid phone number. This will happily convert
  1288. any string.
  1289. For example::
  1290. {{ value|phone2numeric }}
  1291. If ``value`` is ``800-COLLECT``, the output will be ``800-2655328``.
  1292. .. templatefilter:: pluralize
  1293. pluralize
  1294. ^^^^^^^^^
  1295. Returns a plural suffix if the value is not 1. By default, this suffix is
  1296. ``'s'``.
  1297. Example::
  1298. You have {{ num_messages }} message{{ num_messages|pluralize }}.
  1299. If ``num_messages`` is ``1``, the output will be ``You have 1 message.``
  1300. If ``num_messages`` is ``2`` the output will be ``You have 2 messages.``
  1301. For words that require a suffix other than ``'s'``, you can provide an alternate
  1302. suffix as a parameter to the filter.
  1303. Example::
  1304. You have {{ num_walruses }} walrus{{ num_walruses|pluralize:"es" }}.
  1305. For words that don't pluralize by simple suffix, you can specify both a
  1306. singular and plural suffix, separated by a comma.
  1307. Example::
  1308. You have {{ num_cherries }} cherr{{ num_cherries|pluralize:"y,ies" }}.
  1309. .. note:: Use :ttag:`blocktrans` to pluralize translated strings.
  1310. .. templatefilter:: pprint
  1311. pprint
  1312. ^^^^^^
  1313. A wrapper around :func:`pprint.pprint` -- for debugging, really.
  1314. .. templatefilter:: random
  1315. random
  1316. ^^^^^^
  1317. Returns a random item from the given list.
  1318. For example::
  1319. {{ value|random }}
  1320. If ``value`` is the list ``['a', 'b', 'c', 'd']``, the output could be ``"b"``.
  1321. .. templatefilter:: removetags
  1322. removetags
  1323. ^^^^^^^^^^
  1324. .. deprecated:: 1.8
  1325. ``removetags`` cannot guarantee HTML safe output and has been deprecated due
  1326. to security concerns. Consider using `bleach`_ instead.
  1327. .. _bleach: http://bleach.readthedocs.org/en/latest/
  1328. Removes a space-separated list of [X]HTML tags from the output.
  1329. For example::
  1330. {{ value|removetags:"b span" }}
  1331. If ``value`` is ``"<b>Joel</b> <button>is</button> a <span>slug</span>"`` the
  1332. unescaped output will be ``"Joel <button>is</button> a slug"``.
  1333. Note that this filter is case-sensitive.
  1334. If ``value`` is ``"<B>Joel</B> <button>is</button> a <span>slug</span>"`` the
  1335. unescaped output will be ``"<B>Joel</B> <button>is</button> a slug"``.
  1336. .. admonition:: No safety guarantee
  1337. Note that ``removetags`` doesn't give any guarantee about its output being
  1338. HTML safe. In particular, it doesn't work recursively, so an input like
  1339. ``"<sc<script>ript>alert('XSS')</sc</script>ript>"`` won't be safe even if
  1340. you apply ``|removetags:"script"``. So if the input is user provided,
  1341. **NEVER** apply the ``safe`` filter to a ``removetags`` output. If you are
  1342. looking for something more robust, you can use the ``bleach`` Python
  1343. library, notably its `clean`_ method.
  1344. .. _clean: http://bleach.readthedocs.org/en/latest/clean.html
  1345. .. templatefilter:: rjust
  1346. rjust
  1347. ^^^^^
  1348. Right-aligns the value in a field of a given width.
  1349. **Argument:** field size
  1350. For example::
  1351. "{{ value|rjust:"10" }}"
  1352. If ``value`` is ``Django``, the output will be ``" Django"``.
  1353. .. templatefilter:: safe
  1354. safe
  1355. ^^^^
  1356. Marks a string as not requiring further HTML escaping prior to output. When
  1357. autoescaping is off, this filter has no effect.
  1358. .. note::
  1359. If you are chaining filters, a filter applied after ``safe`` can
  1360. make the contents unsafe again. For example, the following code
  1361. prints the variable as is, unescaped:
  1362. .. code-block:: html+django
  1363. {{ var|safe|escape }}
  1364. .. templatefilter:: safeseq
  1365. safeseq
  1366. ^^^^^^^
  1367. Applies the :tfilter:`safe` filter to each element of a sequence. Useful in
  1368. conjunction with other filters that operate on sequences, such as
  1369. :tfilter:`join`. For example::
  1370. {{ some_list|safeseq|join:", " }}
  1371. You couldn't use the :tfilter:`safe` filter directly in this case, as it would
  1372. first convert the variable into a string, rather than working with the
  1373. individual elements of the sequence.
  1374. .. templatefilter:: slice
  1375. slice
  1376. ^^^^^
  1377. Returns a slice of the list.
  1378. Uses the same syntax as Python's list slicing. See
  1379. http://www.diveintopython3.net/native-datatypes.html#slicinglists
  1380. for an introduction.
  1381. Example::
  1382. {{ some_list|slice:":2" }}
  1383. If ``some_list`` is ``['a', 'b', 'c']``, the output will be ``['a', 'b']``.
  1384. .. templatefilter:: slugify
  1385. slugify
  1386. ^^^^^^^
  1387. Converts to ASCII. Converts spaces to hyphens. Removes characters that aren't
  1388. alphanumerics, underscores, or hyphens. Converts to lowercase. Also strips
  1389. leading and trailing whitespace.
  1390. For example::
  1391. {{ value|slugify }}
  1392. If ``value`` is ``"Joel is a slug"``, the output will be ``"joel-is-a-slug"``.
  1393. .. templatefilter:: stringformat
  1394. stringformat
  1395. ^^^^^^^^^^^^
  1396. Formats the variable according to the argument, a string formatting specifier.
  1397. This specifier uses Python string formatting syntax, with the exception that
  1398. the leading "%" is dropped.
  1399. See https://docs.python.org/library/stdtypes.html#string-formatting-operations
  1400. for documentation of Python string formatting
  1401. For example::
  1402. {{ value|stringformat:"E" }}
  1403. If ``value`` is ``10``, the output will be ``1.000000E+01``.
  1404. .. templatefilter:: striptags
  1405. striptags
  1406. ^^^^^^^^^
  1407. Makes all possible efforts to strip all [X]HTML tags.
  1408. For example::
  1409. {{ value|striptags }}
  1410. If ``value`` is ``"<b>Joel</b> <button>is</button> a <span>slug</span>"``, the
  1411. output will be ``"Joel is a slug"``.
  1412. .. admonition:: No safety guarantee
  1413. Note that ``striptags`` doesn't give any guarantee about its output being
  1414. HTML safe, particularly with non valid HTML input. So **NEVER** apply the
  1415. ``safe`` filter to a ``striptags`` output. If you are looking for something
  1416. more robust, you can use the ``bleach`` Python library, notably its
  1417. `clean`_ method.
  1418. .. _clean: http://bleach.readthedocs.org/en/latest/clean.html
  1419. .. templatefilter:: time
  1420. time
  1421. ^^^^
  1422. Formats a time according to the given format.
  1423. Given format can be the predefined one :setting:`TIME_FORMAT`, or a custom
  1424. format, same as the :tfilter:`date` filter. Note that the predefined format
  1425. is locale-dependent.
  1426. For example::
  1427. {{ value|time:"H:i" }}
  1428. If ``value`` is equivalent to ``datetime.datetime.now()``, the output will be
  1429. the string ``"01:23"``.
  1430. Another example:
  1431. Assuming that :setting:`USE_L10N` is ``True`` and :setting:`LANGUAGE_CODE` is,
  1432. for example, ``"de"``, then for::
  1433. {{ value|time:"TIME_FORMAT" }}
  1434. the output will be the string ``"01:23:00"`` (The ``"TIME_FORMAT"`` format
  1435. specifier for the ``de`` locale as shipped with Django is ``"H:i:s"``).
  1436. The ``time`` filter will only accept parameters in the format string that
  1437. relate to the time of day, not the date (for obvious reasons). If you need to
  1438. format a ``date`` value, use the :tfilter:`date` filter instead (or along
  1439. ``time`` if you need to render a full :py:class:`~datetime.datetime` value).
  1440. There is one exception the above rule: When passed a ``datetime`` value with
  1441. attached timezone information (a :ref:`time-zone-aware
  1442. <naive_vs_aware_datetimes>` ``datetime`` instance) the ``time`` filter will
  1443. accept the timezone-related :ref:`format specifiers
  1444. <date-and-time-formatting-specifiers>` ``'e'``, ``'O'`` , ``'T'`` and ``'Z'``.
  1445. When used without a format string::
  1446. {{ value|time }}
  1447. ...the formatting string defined in the :setting:`TIME_FORMAT` setting will be
  1448. used, without applying any localization.
  1449. .. versionchanged:: 1.7
  1450. The ability to receive and act on values with attached timezone
  1451. information was added in Django 1.7.
  1452. .. templatefilter:: timesince
  1453. timesince
  1454. ^^^^^^^^^
  1455. Formats a date as the time since that date (e.g., "4 days, 6 hours").
  1456. Takes an optional argument that is a variable containing the date to use as
  1457. the comparison point (without the argument, the comparison point is *now*).
  1458. For example, if ``blog_date`` is a date instance representing midnight on 1
  1459. June 2006, and ``comment_date`` is a date instance for 08:00 on 1 June 2006,
  1460. then the following would return "8 hours"::
  1461. {{ blog_date|timesince:comment_date }}
  1462. Comparing offset-naive and offset-aware datetimes will return an empty string.
  1463. Minutes is the smallest unit used, and "0 minutes" will be returned for any
  1464. date that is in the future relative to the comparison point.
  1465. .. templatefilter:: timeuntil
  1466. timeuntil
  1467. ^^^^^^^^^
  1468. Similar to ``timesince``, except that it measures the time from now until the
  1469. given date or datetime. For example, if today is 1 June 2006 and
  1470. ``conference_date`` is a date instance holding 29 June 2006, then
  1471. ``{{ conference_date|timeuntil }}`` will return "4 weeks".
  1472. Takes an optional argument that is a variable containing the date to use as
  1473. the comparison point (instead of *now*). If ``from_date`` contains 22 June
  1474. 2006, then the following will return "1 week"::
  1475. {{ conference_date|timeuntil:from_date }}
  1476. Comparing offset-naive and offset-aware datetimes will return an empty string.
  1477. Minutes is the smallest unit used, and "0 minutes" will be returned for any
  1478. date that is in the past relative to the comparison point.
  1479. .. templatefilter:: title
  1480. title
  1481. ^^^^^
  1482. Converts a string into titlecase by making words start with an uppercase
  1483. character and the remaining characters lowercase. This tag makes no effort to
  1484. keep "trivial words" in lowercase.
  1485. For example::
  1486. {{ value|title }}
  1487. If ``value`` is ``"my FIRST post"``, the output will be ``"My First Post"``.
  1488. .. templatefilter:: truncatechars
  1489. truncatechars
  1490. ^^^^^^^^^^^^^
  1491. Truncates a string if it is longer than the specified number of characters.
  1492. Truncated strings will end with a translatable ellipsis sequence ("...").
  1493. **Argument:** Number of characters to truncate to
  1494. For example::
  1495. {{ value|truncatechars:9 }}
  1496. If ``value`` is ``"Joel is a slug"``, the output will be ``"Joel i..."``.
  1497. .. templatefilter:: truncatechars_html
  1498. truncatechars_html
  1499. ^^^^^^^^^^^^^^^^^^
  1500. .. versionadded:: 1.7
  1501. Similar to :tfilter:`truncatechars`, except that it is aware of HTML tags. Any
  1502. tags that are opened in the string and not closed before the truncation point
  1503. are closed immediately after the truncation.
  1504. For example::
  1505. {{ value|truncatechars_html:9 }}
  1506. If ``value`` is ``"<p>Joel is a slug</p>"``, the output will be
  1507. ``"<p>Joel i...</p>"``.
  1508. Newlines in the HTML content will be preserved.
  1509. .. templatefilter:: truncatewords
  1510. truncatewords
  1511. ^^^^^^^^^^^^^
  1512. Truncates a string after a certain number of words.
  1513. **Argument:** Number of words to truncate after
  1514. For example::
  1515. {{ value|truncatewords:2 }}
  1516. If ``value`` is ``"Joel is a slug"``, the output will be ``"Joel is ..."``.
  1517. Newlines within the string will be removed.
  1518. .. templatefilter:: truncatewords_html
  1519. truncatewords_html
  1520. ^^^^^^^^^^^^^^^^^^
  1521. Similar to :tfilter:`truncatewords`, except that it is aware of HTML tags. Any
  1522. tags that are opened in the string and not closed before the truncation point,
  1523. are closed immediately after the truncation.
  1524. This is less efficient than :tfilter:`truncatewords`, so should only be used
  1525. when it is being passed HTML text.
  1526. For example::
  1527. {{ value|truncatewords_html:2 }}
  1528. If ``value`` is ``"<p>Joel is a slug</p>"``, the output will be
  1529. ``"<p>Joel is ...</p>"``.
  1530. Newlines in the HTML content will be preserved.
  1531. .. templatefilter:: unordered_list
  1532. unordered_list
  1533. ^^^^^^^^^^^^^^
  1534. Recursively takes a self-nested list and returns an HTML unordered list --
  1535. WITHOUT opening and closing <ul> tags.
  1536. The list is assumed to be in the proper format. For example, if ``var``
  1537. contains ``['States', ['Kansas', ['Lawrence', 'Topeka'], 'Illinois']]``, then
  1538. ``{{ var|unordered_list }}`` would return::
  1539. <li>States
  1540. <ul>
  1541. <li>Kansas
  1542. <ul>
  1543. <li>Lawrence</li>
  1544. <li>Topeka</li>
  1545. </ul>
  1546. </li>
  1547. <li>Illinois</li>
  1548. </ul>
  1549. </li>
  1550. .. deprecated:: 1.8
  1551. An older, more restrictive and verbose input format is also supported:
  1552. ``['States', [['Kansas', [['Lawrence', []], ['Topeka', []]]], ['Illinois', []]]]``.
  1553. Support for this syntax will be removed in Django 2.0.
  1554. .. templatefilter:: upper
  1555. upper
  1556. ^^^^^
  1557. Converts a string into all uppercase.
  1558. For example::
  1559. {{ value|upper }}
  1560. If ``value`` is ``"Joel is a slug"``, the output will be ``"JOEL IS A SLUG"``.
  1561. .. templatefilter:: urlencode
  1562. urlencode
  1563. ^^^^^^^^^
  1564. Escapes a value for use in a URL.
  1565. For example::
  1566. {{ value|urlencode }}
  1567. If ``value`` is ``"http://www.example.org/foo?a=b&c=d"``, the output will be
  1568. ``"http%3A//www.example.org/foo%3Fa%3Db%26c%3Dd"``.
  1569. An optional argument containing the characters which should not be escaped can
  1570. be provided.
  1571. If not provided, the '/' character is assumed safe. An empty string can be
  1572. provided when *all* characters should be escaped. For example::
  1573. {{ value|urlencode:"" }}
  1574. If ``value`` is ``"http://www.example.org/"``, the output will be
  1575. ``"http%3A%2F%2Fwww.example.org%2F"``.
  1576. .. templatefilter:: urlize
  1577. urlize
  1578. ^^^^^^
  1579. Converts URLs and email addresses in text into clickable links.
  1580. This template tag works on links prefixed with ``http://``, ``https://``, or
  1581. ``www.``. For example, ``http://goo.gl/aia1t`` will get converted but
  1582. ``goo.gl/aia1t`` won't.
  1583. It also supports domain-only links ending in one of the original top level
  1584. domains (``.com``, ``.edu``, ``.gov``, ``.int``, ``.mil``, ``.net``, and
  1585. ``.org``). For example, ``djangoproject.com`` gets converted.
  1586. .. versionchanged:: 1.8
  1587. Support for domain-only links that include characters after the top-level
  1588. domain (e.g. ``djangoproject.com/`` and ``djangoproject.com/download/``)
  1589. was added.
  1590. Links can have trailing punctuation (periods, commas, close-parens) and leading
  1591. punctuation (opening parens), and ``urlize`` will still do the right thing.
  1592. Links generated by ``urlize`` have a ``rel="nofollow"`` attribute added
  1593. to them.
  1594. For example::
  1595. {{ value|urlize }}
  1596. If ``value`` is ``"Check out www.djangoproject.com"``, the output will be
  1597. ``"Check out <a href="http://www.djangoproject.com"
  1598. rel="nofollow">www.djangoproject.com</a>"``.
  1599. In addition to web links, ``urlize`` also converts email addresses into
  1600. ``mailto:`` links. If ``value`` is
  1601. ``"Send questions to foo@example.com"``, the output will be
  1602. ``"Send questions to <a href="mailto:foo@example.com">foo@example</a>"``.
  1603. The ``urlize`` filter also takes an optional parameter ``autoescape``. If
  1604. ``autoescape`` is ``True``, the link text and URLs will be escaped using
  1605. Django's built-in :tfilter:`escape` filter. The default value for
  1606. ``autoescape`` is ``True``.
  1607. .. note::
  1608. If ``urlize`` is applied to text that already contains HTML markup,
  1609. things won't work as expected. Apply this filter only to plain text.
  1610. .. templatefilter:: urlizetrunc
  1611. urlizetrunc
  1612. ^^^^^^^^^^^
  1613. Converts URLs and email addresses into clickable links just like urlize_, but truncates URLs
  1614. longer than the given character limit.
  1615. **Argument:** Number of characters that link text should be truncated to,
  1616. including the ellipsis that's added if truncation is necessary.
  1617. For example::
  1618. {{ value|urlizetrunc:15 }}
  1619. If ``value`` is ``"Check out www.djangoproject.com"``, the output would be
  1620. ``'Check out <a href="http://www.djangoproject.com"
  1621. rel="nofollow">www.djangopr...</a>'``.
  1622. As with urlize_, this filter should only be applied to plain text.
  1623. .. templatefilter:: wordcount
  1624. wordcount
  1625. ^^^^^^^^^
  1626. Returns the number of words.
  1627. For example::
  1628. {{ value|wordcount }}
  1629. If ``value`` is ``"Joel is a slug"``, the output will be ``4``.
  1630. .. templatefilter:: wordwrap
  1631. wordwrap
  1632. ^^^^^^^^
  1633. Wraps words at specified line length.
  1634. **Argument:** number of characters at which to wrap the text
  1635. For example::
  1636. {{ value|wordwrap:5 }}
  1637. If ``value`` is ``Joel is a slug``, the output would be::
  1638. Joel
  1639. is a
  1640. slug
  1641. .. templatefilter:: yesno
  1642. yesno
  1643. ^^^^^
  1644. Maps values for true, false and (optionally) None, to the strings "yes", "no",
  1645. "maybe", or a custom mapping passed as a comma-separated list, and
  1646. returns one of those strings according to the value:
  1647. For example::
  1648. {{ value|yesno:"yeah,no,maybe" }}
  1649. ========== ====================== ==================================
  1650. Value Argument Outputs
  1651. ========== ====================== ==================================
  1652. ``True`` ``yes``
  1653. ``True`` ``"yeah,no,maybe"`` ``yeah``
  1654. ``False`` ``"yeah,no,maybe"`` ``no``
  1655. ``None`` ``"yeah,no,maybe"`` ``maybe``
  1656. ``None`` ``"yeah,no"`` ``"no"`` (converts None to False
  1657. if no mapping for None is given)
  1658. ========== ====================== ==================================
  1659. Internationalization tags and filters
  1660. -------------------------------------
  1661. Django provides template tags and filters to control each aspect of
  1662. :doc:`internationalization </topics/i18n/index>` in templates. They allow for
  1663. granular control of translations, formatting, and time zone conversions.
  1664. i18n
  1665. ^^^^
  1666. This library allows specifying translatable text in templates.
  1667. To enable it, set :setting:`USE_I18N` to ``True``, then load it with
  1668. ``{% load i18n %}``.
  1669. See :ref:`specifying-translation-strings-in-template-code`.
  1670. l10n
  1671. ^^^^
  1672. This library provides control over the localization of values in templates.
  1673. You only need to load the library using ``{% load l10n %}``, but you'll often
  1674. set :setting:`USE_L10N` to ``True`` so that localization is active by default.
  1675. See :ref:`topic-l10n-templates`.
  1676. tz
  1677. ^^
  1678. This library provides control over time zone conversions in templates.
  1679. Like ``l10n``, you only need to load the library using ``{% load tz %}``,
  1680. but you'll usually also set :setting:`USE_TZ` to ``True`` so that conversion
  1681. to local time happens by default.
  1682. See :ref:`time-zones-in-templates`.
  1683. Other tags and filters libraries
  1684. --------------------------------
  1685. Django comes with a couple of other template-tag libraries that you have to
  1686. enable explicitly in your :setting:`INSTALLED_APPS` setting and enable in your
  1687. template with the :ttag:`{% load %}<load>` tag.
  1688. django.contrib.humanize
  1689. ^^^^^^^^^^^^^^^^^^^^^^^
  1690. A set of Django template filters useful for adding a "human touch" to data. See
  1691. :doc:`/ref/contrib/humanize`.
  1692. django.contrib.webdesign
  1693. ^^^^^^^^^^^^^^^^^^^^^^^^
  1694. A collection of template tags that can be useful while designing a Web site,
  1695. such as a generator of Lorem Ipsum text. See :doc:`/ref/contrib/webdesign`.
  1696. static
  1697. ^^^^^^
  1698. .. templatetag:: static
  1699. static
  1700. """"""
  1701. .. highlight:: html+django
  1702. To link to static files that are saved in :setting:`STATIC_ROOT` Django ships
  1703. with a :ttag:`static` template tag. You can use this regardless if you're
  1704. using :class:`~django.template.RequestContext` or not.
  1705. .. code-block:: html+django
  1706. {% load static %}
  1707. <img src="{% static "images/hi.jpg" %}" alt="Hi!" />
  1708. It is also able to consume standard context variables, e.g. assuming a
  1709. ``user_stylesheet`` variable is passed to the template:
  1710. .. code-block:: html+django
  1711. {% load static %}
  1712. <link rel="stylesheet" href="{% static user_stylesheet %}" type="text/css" media="screen" />
  1713. If you'd like to retrieve a static URL without displaying it, you can use a
  1714. slightly different call:
  1715. .. code-block:: html+django
  1716. {% load static %}
  1717. {% static "images/hi.jpg" as myphoto %}
  1718. <img src="{{ myphoto }}"></img>
  1719. .. note::
  1720. The :mod:`staticfiles<django.contrib.staticfiles>` contrib app also ships
  1721. with a :ttag:`static template tag<staticfiles-static>` which uses
  1722. ``staticfiles'`` :setting:`STATICFILES_STORAGE` to build the URL of the
  1723. given path (rather than simply using :func:`urllib.parse.urljoin` with the
  1724. :setting:`STATIC_URL` setting and the given path). Use that instead if you
  1725. have an advanced use case such as :ref:`using a cloud service to serve
  1726. static files<staticfiles-from-cdn>`::
  1727. {% load static from staticfiles %}
  1728. <img src="{% static "images/hi.jpg" %}" alt="Hi!" />
  1729. .. templatetag:: get_static_prefix
  1730. get_static_prefix
  1731. """""""""""""""""
  1732. .. highlight:: html+django
  1733. You should prefer the :ttag:`static` template tag, but if you need more control
  1734. over exactly where and how :setting:`STATIC_URL` is injected into the template,
  1735. you can use the :ttag:`get_static_prefix` template tag::
  1736. {% load static %}
  1737. <img src="{% get_static_prefix %}images/hi.jpg" alt="Hi!" />
  1738. There's also a second form you can use to avoid extra processing if you need
  1739. the value multiple times::
  1740. {% load static %}
  1741. {% get_static_prefix as STATIC_PREFIX %}
  1742. <img src="{{ STATIC_PREFIX }}images/hi.jpg" alt="Hi!" />
  1743. <img src="{{ STATIC_PREFIX }}images/hi2.jpg" alt="Hello!" />
  1744. .. templatetag:: get_media_prefix
  1745. get_media_prefix
  1746. """"""""""""""""
  1747. .. highlight:: html+django
  1748. Similar to the :ttag:`get_static_prefix`, ``get_media_prefix`` populates a
  1749. template variable with the media prefix :setting:`MEDIA_URL`, e.g.::
  1750. <script type="text/javascript" charset="utf-8">
  1751. var media_path = '{% get_media_prefix %}';
  1752. </script>