writing_templates.md 14 KB
(writing_templates)=
Writing templates
Wagtail uses Django's templating language. For developers new to Django, start with Django's own template documentation: [](inv:django#topics/templates)
Python programmers new to Django/Wagtail may prefer more technical documentation: [](inv:django#ref/templates/api)
You should be familiar with Django templating basics before continuing with this documentation.
Templates
Every type of page or "content-type" in Wagtail is defined as a "model" in a file called models.py. If your site has a blog, you might have a BlogPage model and another called BlogPageListing. The names of the models are up to the Django developer.
For each page model in models.py, Wagtail assumes an HTML template file exists of (almost) the same name. The Front End developer may need to create these templates themselves by referring to models.py to infer template names from the models defined therein.
To find a suitable template, Wagtail converts CamelCase names to snake_case. So for a BlogPage model, a template blog_page.html will be expected. The name of the template file can be overridden per model if necessary.
Template files are assumed to exist here:
name_of_project/
name_of_app/
templates/
name_of_app/
blog_page.html
models.py
For more information, see the Django documentation for the application directories template loader.
Page content
The data/content entered into each page is accessed/output through Django's {{ double-brace }} notation. Each field from the model must be accessed by prefixing page.. For example the page title {{ page.title }} or another field {{ page.author }}.
A custom variable name can be configured on the page model {attr}wagtail.models.Page.context_object_name. If a custom name is defined, page is still available for use in shared templates.
Additionally, request. is available and contains Django's request object.
Static assets
Static files (such as CSS, JS, and images) are typically stored here:
name_of_project/
name_of_app/
static/
name_of_app/
css/
js/
images/
models.py
(The names "css", "js" etc aren't important, only their position within the tree.)
Any file within the static folder should be inserted into your HTML using the {% static %} tag. More about it: [](static_tag).
User images
Images uploaded to a Wagtail site by its users (as opposed to a developer's static files, mentioned above) go into the image library and from there are added to pages via the page editor interface.
Unlike other CMSs, adding images to a page does not involve choosing a "version" of the image to use. Wagtail has no predefined image "formats" or "sizes". Instead, the template developer defines image manipulation to occur on the fly when the image is requested, via a special syntax within the template.
Images from the library must be requested using this syntax, but a developer's static images can be added via conventional means like img tags. Only images from the library can be manipulated on the fly.
Read more about the image manipulation syntax here: [](image_tag).
(template_tags_and_filters)=
Template tags & filters
In addition to Django's standard tags and filters, Wagtail provides some of its own, which can be load-ed just like any other.
Images (tag)
The image tag inserts an XHTML-compatible img element into the page, setting its src, width, height, and alt. See also [](image_tag_alt).
The syntax for the image tag is thus:
{% image [image] [resize-rule] %}
For example:
{% load wagtailimages_tags %}
...
{% image page.photo width-400 %}
<!-- or a square thumbnail: -->
{% image page.photo fill-80x80 %}
See [](image_tag) for full documentation.
Images in multiple formats
The picture tag works like image, but allows specifying multiple formats to generate a <picture> element with <source> elements and a fallback <img>.
For example:
{% load wagtailimages_tags %}
...
{% picture page.photo format-{avif,webp,jpeg} width-400 %}
See [](multiple_formats) for full documentation.
Images in multiple sizes
The srcset_image tag works like image, but allows specifying multiple sizes to generate a srcset attribute and leverage responsive image rules.
For example:
{% load wagtailimages_tags %}
...
{% srcset_image page.photo width-{400,800} sizes="(max-width: 600px) 400px, 80vw" %}
This can also be done with picture, to generate multiple formats and sizes at once:
{% picture page.photo format-{avif,webp,jpeg} width-{400,800} sizes="80vw" %}
See [](responsive_images) for full documentation.
(rich_text_filter)=
Rich text (filter)
This filter takes a chunk of HTML content and renders it as safe HTML on the page. Importantly, it also expands internal shorthand references to embedded images and links made in the Wagtail editor, into fully-baked HTML ready for display.
Only fields using RichTextField need this applied in the template.
{% load wagtailcore_tags %}
...
{{ page.body|richtext }}
(responsive_embeds)=
Responsive Embeds
As Wagtail does not impose any styling of its own on templates, images, and embedded media will be displayed at a fixed width as determined by the HTML. Images can be made to resize to fit their container using a CSS rule such as the following:
.body img {
max-width: 100%;
height: auto;
}
where body is a container element in your template surrounding the images.
Making embedded media resizable is also possible, but typically requires custom style rules matching the media's aspect ratio. To assist in this, Wagtail provides built-in support for responsive embeds, which can be enabled by setting WAGTAILEMBEDS_RESPONSIVE_HTML = True in your project settings. This adds a CSS class of responsive-object and an inline padding-bottom style to the embed, to be used in conjunction with the following CSS:
.responsive-object {
position: relative;
}
.responsive-object iframe,
.responsive-object object,
.responsive-object embed {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
}
Internal links (tag)
(pageurl_tag)=
pageurl
Takes a Page object and returns a relative URL (/foo/bar/) if within the same Site as the current page, or absolute (http://example.com/foo/bar/) if not.
{% load wagtailcore_tags %}
...
<a href="{% pageurl page.get_parent %}">Back to index</a>
A fallback keyword argument can be provided - this can be a URL string, a named URL route that can be resolved with no parameters, or an object with a get_absolute_url method, and will be used as a substitute URL when the passed page is None.
{% load wagtailcore_tags %}
{% for publication in page.related_publications.all %}
<li>
<a href="{% pageurl publication.detail_page fallback='coming_soon' %}">
{{ publication.title }}
</a>
</li>
{% endfor %}
(fullpageurl_tag)=
fullpageurl
Takes a Page object and returns its absolute URL (http://example.com/foo/bar/).
{% load wagtailcore_tags %}
...
<meta property="og:url" content="{% fullpageurl page %}" />
Much like pageurl, a fallback keyword argument may be provided.
(slugurl_tag)=
slugurl
Takes any slug as defined in a page's "Promote" tab and returns the URL for the matching Page. If multiple pages exist with the same slug, the page chosen is undetermined.
Like pageurl, this will try to provide a relative link if possible but will default to an absolute link if the Page is on a different Site. This is most useful when creating shared page furniture, for example, top-level navigation or site-wide links.
{% load wagtailcore_tags %}
...
<a href="{% slugurl 'news' %}">News index</a>
(static_tag)=
Static files (tag)
Used to load anything from your static files directory. Use of this tag avoids rewriting all static paths if hosting arrangements change, such as when moving from development to a live environment.
{% load static %}
...
<img src="{% static "name_of_app/myimage.jpg" %}" alt="My image"/>
Notice that the full path is not required - the path given here is relative to the app's static directory. To avoid clashes with static files from other apps (including Wagtail itself), it's recommended to place static files in a subdirectory of static with the same name as the app.
Multi-site support
(wagtail_site_tag)=
wagtail_site
Returns the Site object corresponding to the current request.
{% load wagtailcore_tags %}
{% wagtail_site as current_site %}
(wagtailuserbar_tag)=
Wagtail user bar
This tag provides a contextual flyout menu for logged-in users. The menu gives editors the ability to edit the current page or add a child page, besides the options to show the page in the Wagtail page explorer or jump to the Wagtail admin dashboard. Moderators are also given the ability to accept or reject a page being previewed as part of content moderation.
This tag may be used on standard Django views, without page object. The user bar will contain one item pointing to the admin.
We recommend putting the tag near the top of the <body> element to allow keyboard users to reach it. You should consider putting the tag after any skip links but before the navigation and main content of your page.
{% load wagtailuserbar %}
...
<body>
<a id="#content">Skip to content</a>
{% wagtailuserbar %} {# This is a good place for the user bar #}
<nav>
...
</nav>
<main id="content">
...
</main>
</body>
By default, the user bar appears in the bottom right of the browser window, inset from the edge. If this conflicts with your design it can be moved by passing a parameter to the template tag. These examples show you how to position the user bar in each corner of the screen:
...
{% wagtailuserbar 'top-left' %}
{% wagtailuserbar 'top-right' %}
{% wagtailuserbar 'bottom-left' %}
{% wagtailuserbar 'bottom-right' %}
...
The user bar can be positioned where it works best with your design. Alternatively, you can position it with a CSS rule in your own CSS files, for example:
wagtail-userbar::part(userbar) {
bottom: 30px;
}
To customize the items shown in the user bar, you can use the construct_wagtail_userbar hook.
Varying output between preview and live
Sometimes you may wish to vary the template output depending on whether the page is being previewed or viewed live. For example, if you have visitor-tracking code such as Google Analytics in place on your site, it's a good idea to leave this out when previewing, so that editor activity doesn't appear in your analytics reports. Wagtail provides a request.is_preview variable to distinguish between preview and live:
{% if not request.is_preview %}
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
...
</script>
{% endif %}
If the page is being previewed, request.preview_mode can be used to determine the specific preview mode being used,
if the page supports multiple preview modes.
(template_fragment_caching)=
Template fragment caching
Django supports template fragment caching, which allows caching portions of a template. Using Django's {% cache %} tag natively with Wagtail can be dangerous as it can result in preview content being shown to end users. Instead, Wagtail provides 2 extra template tags which can be loaded from wagtail_cache:
(wagtailcache)=
Preview-aware caching
The {% wagtailcache %} tag functions similarly to Django's {% cache %} tag, but will neither cache nor serve cached content when previewing a page (or other model) in Wagtail.
{% load wagtail_cache %}
{% wagtailcache 500 sidebar %}
<!-- sidebar -->
{% endwagtailcache %}
Much like {% cache %}, you can use make_template_fragment_key to obtain the cache key.
(wagtailpagecache)=
Page-aware caching
{% wagtailpagecache %} is an extension of {% wagtailcache %}, but is also aware of the current page and site, and includes those as part of the cache key. This makes it possible to easily add caching around parts of the page without worrying about the page it's on. {% wagtailpagecache %} intentionally makes assumptions - for more customization it's recommended to use {% wagtailcache %}.
{% load wagtail_cache %}
{% wagtailpagecache 500 hero %}
<!-- hero -->
{% endwagtailpagecache %}
This is identical to:
{% wagtail_site as current_site %}
{% wagtailcache 500 hero page.cache_key current_site.id %}
<!-- hero -->
{% endwagtailcache %}
Note the use of the page's cache key, which ensures that when a page is updated, the cache is automatically invalidated.
If you want to obtain the cache key, you can use make_wagtail_template_fragment_key (based on Django's make_template_fragment_key):
from django.core.cache import cache
from wagtail.coreutils import make_wagtail_template_fragment_key
key = make_wagtail_template_fragment_key("hero", page, site)
cache.delete(key) # invalidates cached template fragment