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backwards compatible for all practical purposes. Fixed #2391, #2489, #2996, #3322, #3344, #3370, #3406, #3432, #3454, #3492, #3582, #3690, #3878, #3891, #3937, #4039, #4141, #4227, #4286, #4291, #4300, #4452, #4702 git-svn-id: http://code.djangoproject.com/svn/django/trunk@5609 bcc190cf-cafb-0310-a4f2-bffc1f526a37
1343 lines
42 KiB
Plaintext
1343 lines
42 KiB
Plaintext
==================================================
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The Django template language: For template authors
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==================================================
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Django's template language is designed to strike a balance between power and
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ease. It's designed to feel comfortable to those used to working with HTML. If
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you have any exposure to other text-based template languages, such as Smarty_
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or CheetahTemplate_, you should feel right at home with Django's templates.
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.. _Smarty: http://smarty.php.net/
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.. _CheetahTemplate: http://www.cheetahtemplate.org/
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Templates
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=========
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A template is simply a text file. It can generate any text-based format (HTML,
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XML, CSV, etc.).
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A template contains **variables**, which get replaced with values when the
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template is evaluated, and **tags**, which control the logic of the template.
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Below is a minimal template that illustrates a few basics. Each element will be
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explained later in this document.::
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{% extends "base_generic.html" %}
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{% block title %}{{ section.title }}{% endblock %}
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{% block content %}
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<h1>{{ section.title }}</h1>
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{% for story in story_list %}
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<h2>
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<a href="{{ story.get_absolute_url }}">
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{{ story.headline|upper }}
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</a>
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</h2>
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<p>{{ story.tease|truncatewords:"100" }}</p>
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{% endfor %}
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{% endblock %}
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.. admonition:: Philosophy
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Why use a text-based template instead of an XML-based one (like Zope's
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TAL)? We wanted Django's template language to be usable for more than
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just XML/HTML templates. At World Online, we use it for e-mails,
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JavaScript and CSV. You can use the template language for any text-based
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format.
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Oh, and one more thing: Making humans edit XML is sadistic!
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Variables
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=========
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Variables look like this: ``{{ variable }}``. When the template engine
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encounters a variable, it evaluates that variable and replaces it with the
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result.
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Use a dot (``.``) to access attributes of a variable.
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.. admonition:: Behind the scenes
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Technically, when the template system encounters a dot, it tries the
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following lookups, in this order:
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* Dictionary lookup
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* Attribute lookup
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* Method call
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* List-index lookup
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In the above example, ``{{ section.title }}`` will be replaced with the
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``title`` attribute of the ``section`` object.
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If you use a variable that doesn't exist, the template system will insert
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the value of the ``TEMPLATE_STRING_IF_INVALID`` setting, which is set to ``''``
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(the empty string) by default.
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See `Using the built-in reference`_, below, for help on finding what variables
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are available in a given template.
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Filters
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=======
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You can modify variables for display by using **filters**.
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Filters look like this: ``{{ name|lower }}``. This displays the value of the
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``{{ name }}`` variable after being filtered through the ``lower`` filter,
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which converts text to lowercase. Use a pipe (``|``) to apply a filter.
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Filters can be "chained." The output of one filter is applied to the next.
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``{{ text|escape|linebreaks }}`` is a common idiom for escaping text contents,
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then converting line breaks to ``<p>`` tags.
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Some filters take arguments. A filter argument looks like this: ``{{
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bio|truncatewords:30 }}``. This will display the first 30 words of the ``bio``
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variable.
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Filter arguments that contain spaces must be quoted; for example, to join a list
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with commas and spaced you'd use ``{{ list|join:", " }}``.
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The `Built-in filter reference`_ below describes all the built-in filters.
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Tags
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====
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Tags look like this: ``{% tag %}``. Tags are more complex than variables: Some
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create text in the output, some control flow by performing loops or logic, and
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some load external information into the template to be used by later variables.
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Some tags require beginning and ending tags (i.e.
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``{% tag %} ... tag contents ... {% endtag %}``). The `Built-in tag reference`_
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below describes all the built-in tags. You can create your own tags, if you
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know how to write Python code.
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Comments
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========
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To comment-out part of a line in a template, use the comment syntax: ``{# #}``.
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For example, this template would render as ``'hello'``::
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{# greeting #}hello
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A comment can contain any template code, invalid or not. For example::
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{# {% if foo %}bar{% else %} #}
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This syntax can only be used for single-line comments (no newlines are
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permitted between the ``{#`` and ``#}`` delimiters). If you need to comment
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out a multiline portion of the template, see the ``comment`` tag, below__.
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__ comment_
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Template inheritance
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====================
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The most powerful -- and thus the most complex -- part of Django's template
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engine is template inheritance. Template inheritance allows you to build a base
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"skeleton" template that contains all the common elements of your site and
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defines **blocks** that child templates can override.
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It's easiest to understand template inheritance by starting with an example::
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
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<head>
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<link rel="stylesheet" href="style.css" />
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<title>{% block title %}My amazing site{% endblock %}</title>
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</head>
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<body>
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<div id="sidebar">
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{% block sidebar %}
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<ul>
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<li><a href="/">Home</a></li>
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<li><a href="/blog/">Blog</a></li>
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</ul>
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{% endblock %}
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</div>
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<div id="content">
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{% block content %}{% endblock %}
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</div>
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</body>
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</html>
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This template, which we'll call ``base.html``, defines a simple HTML skeleton
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document that you might use for a simple two-column page. It's the job of
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"child" templates to fill the empty blocks with content.
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In this example, the ``{% block %}`` tag defines three blocks that child
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templates can fill in. All the ``block`` tag does is to tell the template
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engine that a child template may override those portions of the template.
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A child template might look like this::
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{% extends "base.html" %}
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{% block title %}My amazing blog{% endblock %}
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{% block content %}
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{% for entry in blog_entries %}
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<h2>{{ entry.title }}</h2>
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<p>{{ entry.body }}</p>
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{% endfor %}
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{% endblock %}
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The ``{% extends %}`` tag is the key here. It tells the template engine that
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this template "extends" another template. When the template system evaluates
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this template, first it locates the parent -- in this case, "base.html".
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At that point, the template engine will notice the three ``{% block %}`` tags
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in ``base.html`` and replace those blocks with the contents of the child
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template. Depending on the value of ``blog_entries``, the output might look
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like::
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
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<head>
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<link rel="stylesheet" href="style.css" />
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<title>My amazing blog</title>
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</head>
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<body>
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<div id="sidebar">
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<ul>
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<li><a href="/">Home</a></li>
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<li><a href="/blog/">Blog</a></li>
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</ul>
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</div>
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<div id="content">
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<h2>Entry one</h2>
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<p>This is my first entry.</p>
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<h2>Entry two</h2>
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<p>This is my second entry.</p>
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</div>
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</body>
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</html>
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Note that since the child template didn't define the ``sidebar`` block, the
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value from the parent template is used instead. Content within a ``{% block %}``
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tag in a parent template is always used as a fallback.
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You can use as many levels of inheritance as needed. One common way of using
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inheritance is the following three-level approach:
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* Create a ``base.html`` template that holds the main look-and-feel of your
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site.
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* Create a ``base_SECTIONNAME.html`` template for each "section" of your
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site. For example, ``base_news.html``, ``base_sports.html``. These
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templates all extend ``base.html`` and include section-specific
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styles/design.
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* Create individual templates for each type of page, such as a news
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article or blog entry. These templates extend the appropriate section
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template.
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This approach maximizes code reuse and makes it easy to add items to shared
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content areas, such as section-wide navigation.
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Here are some tips for working with inheritance:
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* If you use ``{% extends %}`` in a template, it must be the first template
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tag in that template. Template inheritance won't work, otherwise.
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* More ``{% block %}`` tags in your base templates are better. Remember,
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child templates don't have to define all parent blocks, so you can fill
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in reasonable defaults in a number of blocks, then only define the ones
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you need later. It's better to have more hooks than fewer hooks.
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* If you find yourself duplicating content in a number of templates, it
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probably means you should move that content to a ``{% block %}`` in a
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parent template.
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* If you need to get the content of the block from the parent template,
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the ``{{ block.super }}`` variable will do the trick. This is useful
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if you want to add to the contents of a parent block instead of
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completely overriding it.
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* For extra readability, you can optionally give a *name* to your
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``{% endblock %}`` tag. For example::
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{% block content %}
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...
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{% endblock content %}
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In larger templates, this technique helps you see which ``{% block %}``
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tags are being closed.
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Finally, note that you can't define multiple ``{% block %}`` tags with the same
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name in the same template. This limitation exists because a block tag works in
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"both" directions. That is, a block tag doesn't just provide a hole to fill --
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it also defines the content that fills the hole in the *parent*. If there were
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two similarly-named ``{% block %}`` tags in a template, that template's parent
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wouldn't know which one of the blocks' content to use.
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Using the built-in reference
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============================
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Django's admin interface includes a complete reference of all template tags and
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filters available for a given site. To see it, go to your admin interface and
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click the "Documentation" link in the upper right of the page.
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The reference is divided into 4 sections: tags, filters, models, and views.
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The **tags** and **filters** sections describe all the built-in tags (in fact,
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the tag and filter references below come directly from those pages) as well as
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any custom tag or filter libraries available.
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The **views** page is the most valuable. Each URL in your site has a separate
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entry here, and clicking on a URL will show you:
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* The name of the view function that generates that view.
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* A short description of what the view does.
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* The **context**, or a list of variables available in the view's template.
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* The name of the template or templates that are used for that view.
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Each view documentation page also has a bookmarklet that you can use to jump
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from any page to the documentation page for that view.
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Because Django-powered sites usually use database objects, the **models**
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section of the documentation page describes each type of object in the system
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along with all the fields available on that object.
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Taken together, the documentation pages should tell you every tag, filter,
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variable and object available to you in a given template.
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Custom tag and filter libraries
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===============================
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Certain applications provide custom tag and filter libraries. To access them in
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a template, use the ``{% load %}`` tag::
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{% load comments %}
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{% comment_form for blogs.entries entry.id with is_public yes %}
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In the above, the ``load`` tag loads the ``comments`` tag library, which then
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makes the ``comment_form`` tag available for use. Consult the documentation
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area in your admin to find the list of custom libraries in your installation.
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The ``{% load %}`` tag can take multiple library names, separated by spaces.
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Example::
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{% load comments i18n %}
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Custom libraries and template inheritance
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-----------------------------------------
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When you load a custom tag or filter library, the tags/filters are only made
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available to the current template -- not any parent or child templates along
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the template-inheritance path.
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For example, if a template ``foo.html`` has ``{% load comments %}``, a child
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template (e.g., one that has ``{% extends "foo.html" %}``) will *not* have
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access to the comments template tags and filters. The child template is
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responsible for its own ``{% load comments %}``.
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This is a feature for the sake of maintainability and sanity.
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Built-in tag and filter reference
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=================================
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For those without an admin site available, reference for the stock tags and
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filters follows. Because Django is highly customizable, the reference in your
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admin should be considered the final word on what tags and filters are
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available, and what they do.
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Built-in tag reference
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----------------------
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block
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~~~~~
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Define a block that can be overridden by child templates. See
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`Template inheritance`_ for more information.
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comment
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~~~~~~~
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Ignore everything between ``{% comment %}`` and ``{% endcomment %}``
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cycle
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~~~~~
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Cycle among the given strings each time this tag is encountered.
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Within a loop, cycles among the given strings each time through the loop::
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{% for o in some_list %}
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<tr class="{% cycle row1,row2 %}">
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...
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</tr>
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{% endfor %}
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Outside of a loop, give the values a unique name the first time you call it,
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then use that name each successive time through::
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<tr class="{% cycle row1,row2,row3 as rowcolors %}">...</tr>
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<tr class="{% cycle rowcolors %}">...</tr>
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<tr class="{% cycle rowcolors %}">...</tr>
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You can use any number of values, separated by commas. Make sure not to put
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spaces between the values -- only commas.
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debug
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~~~~~
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Output a whole load of debugging information, including the current context and
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imported modules.
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extends
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~~~~~~~
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Signal that this template extends a parent template.
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This tag can be used in two ways:
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* ``{% extends "base.html" %}`` (with quotes) uses the literal value
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``"base.html"`` as the name of the parent template to extend.
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* ``{% extends variable %}`` uses the value of ``variable``. If the variable
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evaluates to a string, Django will use that string as the name of the
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parent template. If the variable evaluates to a ``Template`` object,
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Django will use that object as the parent template.
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See `Template inheritance`_ for more information.
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filter
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~~~~~~
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Filter the contents of the variable through variable filters.
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Filters can also be piped through each other, and they can have arguments --
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just like in variable syntax.
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Sample usage::
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{% filter escape|lower %}
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This text will be HTML-escaped, and will appear in all lowercase.
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{% endfilter %}
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firstof
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~~~~~~~
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Outputs the first variable passed that is not False. Outputs nothing if all the
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passed variables are False.
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Sample usage::
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{% firstof var1 var2 var3 %}
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This is equivalent to::
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{% if var1 %}
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{{ var1 }}
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{% else %}{% if var2 %}
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{{ var2 }}
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{% else %}{% if var3 %}
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{{ var3 }}
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{% endif %}{% endif %}{% endif %}
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for
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~~~
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Loop over each item in an array. For example, to display a list of athletes
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provided in ``athlete_list``::
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<ul>
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{% for athlete in athlete_list %}
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<li>{{ athlete.name }}</li>
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{% endfor %}
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</ul>
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You can loop over a list in reverse by using ``{% for obj in list reversed %}``.
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**New in Django development version**
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If you need to loop over a list of lists, you can unpack the values
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in eachs sub-list into a set of known names. For example, if your context contains
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a list of (x,y) coordinates called ``points``, you could use the following
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to output the list of points::
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{% for x, y in points %}
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There is a point at {{ x }},{{ y }}
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{% endfor %}
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This can also be useful if you need to access the items in a dictionary.
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For example, if your context contained a dictionary ``data``, the following
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would display the keys and values of the dictionary::
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{% for key, value in data.items %}
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{{ key }}: {{ value }}
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{% endfor %}
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The for loop sets a number of variables available within the loop:
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========================== ================================================
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Variable Description
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========================== ================================================
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``forloop.counter`` The current iteration of the loop (1-indexed)
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``forloop.counter0`` The current iteration of the loop (0-indexed)
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``forloop.revcounter`` The number of iterations from the end of the
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loop (1-indexed)
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``forloop.revcounter0`` The number of iterations from the end of the
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loop (0-indexed)
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``forloop.first`` True if this is the first time through the loop
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``forloop.last`` True if this is the last time through the loop
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``forloop.parentloop`` For nested loops, this is the loop "above" the
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current one
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========================== ================================================
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if
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~~
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The ``{% if %}`` tag evaluates a variable, and if that variable is "true" (i.e.
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exists, is not empty, and is not a false boolean value) the contents of the
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block are output::
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{% if athlete_list %}
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Number of athletes: {{ athlete_list|length }}
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{% else %}
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No athletes.
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{% endif %}
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In the above, if ``athlete_list`` is not empty, the number of athletes will be
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displayed by the ``{{ athlete_list|length }}`` variable.
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As you can see, the ``if`` tag can take an optional ``{% else %}`` clause that
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will be displayed if the test fails.
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``if`` tags may use ``and``, ``or`` or ``not`` to test a number of variables or
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to negate a given variable::
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{% if athlete_list and coach_list %}
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Both athletes and coaches are available.
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{% endif %}
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{% if not athlete_list %}
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There are no athletes.
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{% endif %}
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{% if athlete_list or coach_list %}
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|
There are some athletes or some coaches.
|
|
{% endif %}
|
|
|
|
{% if not athlete_list or coach_list %}
|
|
There are no athletes or there are some coaches (OK, so
|
|
writing English translations of boolean logic sounds
|
|
stupid; it's not our fault).
|
|
{% endif %}
|
|
|
|
{% if athlete_list and not coach_list %}
|
|
There are some athletes and absolutely no coaches.
|
|
{% endif %}
|
|
|
|
``if`` tags don't allow ``and`` and ``or`` clauses within the same tag, because
|
|
the order of logic would be ambiguous. For example, this is invalid::
|
|
|
|
{% if athlete_list and coach_list or cheerleader_list %}
|
|
|
|
If you need to combine ``and`` and ``or`` to do advanced logic, just use nested
|
|
``if`` tags. For example::
|
|
|
|
{% if athlete_list %}
|
|
{% if coach_list or cheerleader_list %}
|
|
We have athletes, and either coaches or cheerleaders!
|
|
{% endif %}
|
|
{% endif %}
|
|
|
|
Multiple uses of the same logical operator are fine, as long as you use the
|
|
same operator. For example, this is valid::
|
|
|
|
{% if athlete_list or coach_list or parent_list or teacher_list %}
|
|
|
|
ifchanged
|
|
~~~~~~~~~
|
|
|
|
Check if a value has changed from the last iteration of a loop.
|
|
|
|
The 'ifchanged' block tag is used within a loop. It has two possible uses.
|
|
|
|
1. Checks its own rendered contents against its previous state and only
|
|
displays the content if it has changed. For example, this displays a list of
|
|
days, only displaying the month if it changes::
|
|
|
|
<h1>Archive for {{ year }}</h1>
|
|
|
|
{% for date in days %}
|
|
{% ifchanged %}<h3>{{ date|date:"F" }}</h3>{% endifchanged %}
|
|
<a href="{{ date|date:"M/d"|lower }}/">{{ date|date:"j" }}</a>
|
|
{% endfor %}
|
|
|
|
2. If given a variable, check whether that variable has changed. For
|
|
example, the following shows the date every time it changes, but
|
|
only shows the hour if both the hour and the date has changed::
|
|
|
|
{% for date in days %}
|
|
{% ifchanged date.date %} {{ date.date }} {% endifchanged %}
|
|
{% ifchanged date.hour date.date %}
|
|
{{ date.hour }}
|
|
{% endifchanged %}
|
|
{% endfor %}
|
|
|
|
ifequal
|
|
~~~~~~~
|
|
|
|
Output the contents of the block if the two arguments equal each other.
|
|
|
|
Example::
|
|
|
|
{% ifequal user.id comment.user_id %}
|
|
...
|
|
{% endifequal %}
|
|
|
|
As in the ``{% if %}`` tag, an ``{% else %}`` clause is optional.
|
|
|
|
The arguments can be hard-coded strings, so the following is valid::
|
|
|
|
{% ifequal user.username "adrian" %}
|
|
...
|
|
{% endifequal %}
|
|
|
|
It is only possible to compare an argument to template variables or strings.
|
|
You cannot check for equality with Python objects such as ``True`` or
|
|
``False``. If you need to test if something is true or false, use the ``if``
|
|
tag instead.
|
|
|
|
ifnotequal
|
|
~~~~~~~~~~
|
|
|
|
Just like ``ifequal``, except it tests that the two arguments are not equal.
|
|
|
|
include
|
|
~~~~~~~
|
|
|
|
Loads a template and renders it with the current context. This is a way of
|
|
"including" other templates within a template.
|
|
|
|
The template name can either be a variable or a hard-coded (quoted) string,
|
|
in either single or double quotes.
|
|
|
|
This example includes the contents of the template ``"foo/bar.html"``::
|
|
|
|
{% include "foo/bar.html" %}
|
|
|
|
This example includes the contents of the template whose name is contained in
|
|
the variable ``template_name``::
|
|
|
|
{% include template_name %}
|
|
|
|
An included template is rendered with the context of the template that's
|
|
including it. This example produces the output ``"Hello, John"``:
|
|
|
|
* Context: variable ``person`` is set to ``"john"``.
|
|
* Template::
|
|
|
|
{% include "name_snippet.html" %}
|
|
|
|
* The ``name_snippet.html`` template::
|
|
|
|
Hello, {{ person }}
|
|
|
|
See also: ``{% ssi %}``.
|
|
|
|
load
|
|
~~~~
|
|
|
|
Load a custom template tag set.
|
|
|
|
See `Custom tag and filter libraries`_ for more information.
|
|
|
|
now
|
|
~~~
|
|
|
|
Display the date, formatted according to the given string.
|
|
|
|
Uses the same format as PHP's ``date()`` function (http://php.net/date)
|
|
with some custom extensions.
|
|
|
|
Available format strings:
|
|
|
|
================ ======================================== =====================
|
|
Format character Description Example output
|
|
================ ======================================== =====================
|
|
a ``'a.m.'`` or ``'p.m.'`` (Note that ``'a.m.'``
|
|
this is slightly different than PHP's
|
|
output, because this includes periods
|
|
to match Associated Press style.)
|
|
A ``'AM'`` or ``'PM'``. ``'AM'``
|
|
b Month, textual, 3 letters, lowercase. ``'jan'``
|
|
B Not implemented.
|
|
d Day of the month, 2 digits with ``'01'`` to ``'31'``
|
|
leading zeros.
|
|
D Day of the week, textual, 3 letters. ``'Fri'``
|
|
f Time, in 12-hour hours and minutes, ``'1'``, ``'1:30'``
|
|
with minutes left off if they're zero.
|
|
Proprietary extension.
|
|
F Month, textual, long. ``'January'``
|
|
g Hour, 12-hour format without leading ``'1'`` to ``'12'``
|
|
zeros.
|
|
G Hour, 24-hour format without leading ``'0'`` to ``'23'``
|
|
zeros.
|
|
h Hour, 12-hour format. ``'01'`` to ``'12'``
|
|
H Hour, 24-hour format. ``'00'`` to ``'23'``
|
|
i Minutes. ``'00'`` to ``'59'``
|
|
I Not implemented.
|
|
j Day of the month without leading ``'1'`` to ``'31'``
|
|
zeros.
|
|
l Day of the week, textual, long. ``'Friday'``
|
|
L Boolean for whether it's a leap year. ``True`` or ``False``
|
|
m Month, 2 digits with leading zeros. ``'01'`` to ``'12'``
|
|
M Month, textual, 3 letters. ``'Jan'``
|
|
n Month without leading zeros. ``'1'`` to ``'12'``
|
|
N Month abbreviation in Associated Press ``'Jan.'``, ``'Feb.'``, ``'March'``, ``'May'``
|
|
style. Proprietary extension.
|
|
O Difference to Greenwich time in hours. ``'+0200'``
|
|
P Time, in 12-hour hours, minutes and ``'1 a.m.'``, ``'1:30 p.m.'``, ``'midnight'``, ``'noon'``, ``'12:30 p.m.'``
|
|
'a.m.'/'p.m.', with minutes left off
|
|
if they're zero and the special-case
|
|
strings 'midnight' and 'noon' if
|
|
appropriate. Proprietary extension.
|
|
r RFC 822 formatted date. ``'Thu, 21 Dec 2000 16:01:07 +0200'``
|
|
s Seconds, 2 digits with leading zeros. ``'00'`` to ``'59'``
|
|
S English ordinal suffix for day of the ``'st'``, ``'nd'``, ``'rd'`` or ``'th'``
|
|
month, 2 characters.
|
|
t Number of days in the given month. ``28`` to ``31``
|
|
T Time zone of this machine. ``'EST'``, ``'MDT'``
|
|
U Not implemented.
|
|
w Day of the week, digits without ``'0'`` (Sunday) to ``'6'`` (Saturday)
|
|
leading zeros.
|
|
W ISO-8601 week number of year, with ``1``, ``23``
|
|
weeks starting on Monday.
|
|
y Year, 2 digits. ``'99'``
|
|
Y Year, 4 digits. ``'1999'``
|
|
z Day of the year. ``0`` to ``365``
|
|
Z Time zone offset in seconds. The ``-43200`` to ``43200``
|
|
offset for timezones west of UTC is
|
|
always negative, and for those east of
|
|
UTC is always positive.
|
|
================ ======================================== =====================
|
|
|
|
Example::
|
|
|
|
It is {% now "jS F Y H:i" %}
|
|
|
|
Note that you can backslash-escape a format string if you want to use the
|
|
"raw" value. In this example, "f" is backslash-escaped, because otherwise
|
|
"f" is a format string that displays the time. The "o" doesn't need to be
|
|
escaped, because it's not a format character::
|
|
|
|
It is the {% now "jS o\f F" %}
|
|
|
|
This would display as "It is the 4th of September".
|
|
|
|
regroup
|
|
~~~~~~~
|
|
|
|
Regroup a list of alike objects by a common attribute.
|
|
|
|
This complex tag is best illustrated by use of an example: say that ``people``
|
|
is a list of ``Person`` objects that have ``first_name``, ``last_name``, and
|
|
``gender`` attributes, and you'd like to display a list that looks like:
|
|
|
|
* Male:
|
|
* George Bush
|
|
* Bill Clinton
|
|
* Female:
|
|
* Margaret Thatcher
|
|
* Condoleezza Rice
|
|
* Unknown:
|
|
* Pat Smith
|
|
|
|
The following snippet of template code would accomplish this dubious task::
|
|
|
|
{% regroup people by gender as grouped %}
|
|
<ul>
|
|
{% for group in grouped %}
|
|
<li>{{ group.grouper }}
|
|
<ul>
|
|
{% for item in group.list %}
|
|
<li>{{ item }}</li>
|
|
{% endfor %}
|
|
</ul>
|
|
</li>
|
|
{% endfor %}
|
|
</ul>
|
|
|
|
As you can see, ``{% regroup %}`` populates a variable with a list of objects
|
|
with ``grouper`` and ``list`` attributes. ``grouper`` contains the item that
|
|
was grouped by; ``list`` contains the list of objects that share that
|
|
``grouper``. In this case, ``grouper`` would be ``Male``, ``Female`` and
|
|
``Unknown``, and ``list`` is the list of people with those genders.
|
|
|
|
Note that ``{% regroup %}`` does not work when the list to be grouped is not
|
|
sorted by the key you are grouping by! This means that if your list of people
|
|
was not sorted by gender, you'd need to make sure it is sorted before using it,
|
|
i.e.::
|
|
|
|
{% regroup people|dictsort:"gender" by gender as grouped %}
|
|
|
|
spaceless
|
|
~~~~~~~~~
|
|
|
|
Removes whitespace between HTML tags. This includes tab
|
|
characters and newlines.
|
|
|
|
Example usage::
|
|
|
|
{% spaceless %}
|
|
<p>
|
|
<a href="foo/">Foo</a>
|
|
</p>
|
|
{% endspaceless %}
|
|
|
|
This example would return this HTML::
|
|
|
|
<p><a href="foo/">Foo</a></p>
|
|
|
|
Only space between *tags* is removed -- not space between tags and text. In
|
|
this example, the space around ``Hello`` won't be stripped::
|
|
|
|
{% spaceless %}
|
|
<strong>
|
|
Hello
|
|
</strong>
|
|
{% endspaceless %}
|
|
|
|
ssi
|
|
~~~
|
|
|
|
Output the contents of a given file into the page.
|
|
|
|
Like a simple "include" tag, ``{% ssi %}`` includes the contents of another
|
|
file -- which must be specified using an absolute path -- in the current
|
|
page::
|
|
|
|
{% ssi /home/html/ljworld.com/includes/right_generic.html %}
|
|
|
|
If the optional "parsed" parameter is given, the contents of the included
|
|
file are evaluated as template code, within the current context::
|
|
|
|
{% ssi /home/html/ljworld.com/includes/right_generic.html parsed %}
|
|
|
|
Note that if you use ``{% ssi %}``, you'll need to define
|
|
`ALLOWED_INCLUDE_ROOTS`_ in your Django settings, as a security measure.
|
|
|
|
See also: ``{% include %}``.
|
|
|
|
.. _ALLOWED_INCLUDE_ROOTS: ../settings/#allowed-include-roots
|
|
|
|
templatetag
|
|
~~~~~~~~~~~
|
|
|
|
Output one of the syntax characters used to compose template tags.
|
|
|
|
Since the template system has no concept of "escaping", to display one of the
|
|
bits used in template tags, you must use the ``{% templatetag %}`` tag.
|
|
|
|
The argument tells which template bit to output:
|
|
|
|
================== =======
|
|
Argument Outputs
|
|
================== =======
|
|
``openblock`` ``{%``
|
|
``closeblock`` ``%}``
|
|
``openvariable`` ``{{``
|
|
``closevariable`` ``}}``
|
|
``openbrace`` ``{``
|
|
``closebrace`` ``}``
|
|
``opencomment`` ``{#``
|
|
``closecomment`` ``#}``
|
|
================== =======
|
|
|
|
url
|
|
~~~
|
|
|
|
**Note that the syntax for this tag may change in the future, as we make it more robust.**
|
|
|
|
Returns an absolute URL (i.e., a URL without the domain name) matching a given
|
|
view function and optional parameters. This is a way to output links without
|
|
violating the DRY principle by having to hard-code URLs in your templates::
|
|
|
|
{% url path.to.some_view arg1,arg2,name1=value1 %}
|
|
|
|
The first argument is a path to a view function in the format
|
|
``package.package.module.function``. Additional arguments are optional and
|
|
should be comma-separated values that will be used as positional and keyword
|
|
arguments in the URL. All arguments required by the URLconf should be present.
|
|
|
|
For example, suppose you have a view, ``app_views.client``, whose URLconf
|
|
takes a client ID (here, ``client()`` is a method inside the views file
|
|
``app_views.py``). The URLconf line might look like this::
|
|
|
|
('^client/(\d+)/$', 'app_views.client')
|
|
|
|
If this app's URLconf is included into the project's URLconf under a path
|
|
such as this::
|
|
|
|
('^clients/', include('project_name.app_name.urls'))
|
|
|
|
...then, in a template, you can create a link to this view like this::
|
|
|
|
{% url app_views.client client.id %}
|
|
|
|
The template tag will output the string ``/clients/client/123/``.
|
|
|
|
widthratio
|
|
~~~~~~~~~~
|
|
|
|
For creating bar charts and such, this tag calculates the ratio of a given value
|
|
to a maximum value, and then applies that ratio to a constant.
|
|
|
|
For example::
|
|
|
|
<img src="bar.gif" height="10" width="{% widthratio this_value max_value 100 %}" />
|
|
|
|
Above, if ``this_value`` is 175 and ``max_value`` is 200, the the image in the
|
|
above example will be 88 pixels wide (because 175/200 = .875; .875 * 100 = 87.5
|
|
which is rounded up to 88).
|
|
|
|
with
|
|
~~~~
|
|
|
|
**New in Django development version**
|
|
|
|
Caches a complex variable under a simpler name. This is useful when accessing
|
|
an "expensive" method (e.g., one that hits the database) multiple times.
|
|
|
|
For example::
|
|
|
|
{% with business.employees.count as total %}
|
|
{{ total }} employee{{ total|pluralize }}
|
|
{% endwith %}
|
|
|
|
The populated variable (in the example above, ``total``) is only available
|
|
between the ``{% with %}`` and ``{% endwith %}`` tags.
|
|
|
|
Built-in filter reference
|
|
-------------------------
|
|
|
|
add
|
|
~~~
|
|
|
|
Adds the arg to the value.
|
|
|
|
addslashes
|
|
~~~~~~~~~~
|
|
|
|
Adds slashes. Useful for passing strings to JavaScript, for example.
|
|
|
|
|
|
capfirst
|
|
~~~~~~~~
|
|
|
|
Capitalizes the first character of the value.
|
|
|
|
center
|
|
~~~~~~
|
|
|
|
Centers the value in a field of a given width.
|
|
|
|
cut
|
|
~~~
|
|
|
|
Removes all values of arg from the given string.
|
|
|
|
date
|
|
~~~~
|
|
|
|
Formats a date according to the given format (same as the ``now`` tag).
|
|
|
|
default
|
|
~~~~~~~
|
|
|
|
If value is unavailable, use given default.
|
|
|
|
default_if_none
|
|
~~~~~~~~~~~~~~~
|
|
|
|
If value is ``None``, use given default.
|
|
|
|
dictsort
|
|
~~~~~~~~
|
|
|
|
Takes a list of dicts, returns that list sorted by the property given in the
|
|
argument.
|
|
|
|
dictsortreversed
|
|
~~~~~~~~~~~~~~~~
|
|
|
|
Takes a list of dicts, returns that list sorted in reverse order by the
|
|
property given in the argument.
|
|
|
|
divisibleby
|
|
~~~~~~~~~~~
|
|
|
|
Returns true if the value is divisible by the argument.
|
|
|
|
escape
|
|
~~~~~~
|
|
|
|
Escapes a string's HTML. Specifically, it makes these replacements:
|
|
|
|
* ``"&"`` to ``"&"``
|
|
* ``<`` to ``"<"``
|
|
* ``>`` to ``">"``
|
|
* ``'"'`` (double quote) to ``'"'``
|
|
* ``"'"`` (single quote) to ``'''``
|
|
|
|
filesizeformat
|
|
~~~~~~~~~~~~~~
|
|
|
|
Format the value like a 'human-readable' file size (i.e. ``'13 KB'``,
|
|
``'4.1 MB'``, ``'102 bytes'``, etc).
|
|
|
|
first
|
|
~~~~~
|
|
|
|
Returns the first item in a list.
|
|
|
|
fix_ampersands
|
|
~~~~~~~~~~~~~~
|
|
|
|
Replaces ampersands with ``&`` entities.
|
|
|
|
floatformat
|
|
~~~~~~~~~~~
|
|
|
|
When used without an argument, rounds a floating-point number to one decimal
|
|
place -- but only if there's a decimal part to be displayed. For example:
|
|
|
|
* ``36.123`` gets converted to ``36.1``
|
|
* ``36.15`` gets converted to ``36.2``
|
|
* ``36`` gets converted to ``36``
|
|
|
|
If used with a numeric integer argument, ``floatformat`` rounds a number to that
|
|
many decimal places. For example:
|
|
|
|
* ``36.1234`` with floatformat:3 gets converted to ``36.123``
|
|
* ``36`` with floatformat:4 gets converted to ``36.0000``
|
|
|
|
If the argument passed to ``floatformat`` is negative, it will round a number to
|
|
that many decimal places -- but only if there's a decimal part to be displayed.
|
|
For example:
|
|
|
|
* ``36.1234`` with floatformat:-3 gets converted to ``36.123``
|
|
* ``36`` with floatformat:-4 gets converted to ``36``
|
|
|
|
Using ``floatformat`` with no argument is equivalent to using ``floatformat`` with
|
|
an argument of ``-1``.
|
|
|
|
get_digit
|
|
~~~~~~~~~
|
|
|
|
Given a whole number, returns the requested digit of it, where 1 is the
|
|
right-most digit, 2 is the second-right-most digit, etc. Returns the original
|
|
value for invalid input (if input or argument is not an integer, or if argument
|
|
is less than 1). Otherwise, output is always an integer.
|
|
|
|
iriencode
|
|
~~~~~~~~~
|
|
|
|
Converts an IRI (Internationalized Resource Identifier) to a string that is
|
|
suitable for including in a URL. This is necessary if you're trying to use
|
|
strings containing non-ASCII characters in a URL.
|
|
|
|
It's safe to use this filter on a string that has already gone through the
|
|
``urlencode`` filter.
|
|
|
|
join
|
|
~~~~
|
|
|
|
Joins a list with a string, like Python's ``str.join(list)``.
|
|
|
|
length
|
|
~~~~~~
|
|
|
|
Returns the length of the value. Useful for lists.
|
|
|
|
length_is
|
|
~~~~~~~~~
|
|
|
|
Returns a boolean of whether the value's length is the argument.
|
|
|
|
linebreaks
|
|
~~~~~~~~~~
|
|
|
|
Converts newlines into ``<p>`` and ``<br />`` tags.
|
|
|
|
linebreaksbr
|
|
~~~~~~~~~~~~
|
|
|
|
Converts newlines into ``<br />`` tags.
|
|
|
|
linenumbers
|
|
~~~~~~~~~~~
|
|
|
|
Displays text with line numbers.
|
|
|
|
ljust
|
|
~~~~~
|
|
|
|
Left-aligns the value in a field of a given width.
|
|
|
|
**Argument:** field size
|
|
|
|
lower
|
|
~~~~~
|
|
|
|
Converts a string into all lowercase.
|
|
|
|
make_list
|
|
~~~~~~~~~
|
|
|
|
Returns the value turned into a list. For an integer, it's a list of
|
|
digits. For a string, it's a list of characters.
|
|
|
|
phone2numeric
|
|
~~~~~~~~~~~~~
|
|
|
|
Converts a phone number (possibly containing letters) to its numerical
|
|
equivalent. For example, ``'800-COLLECT'`` will be converted to
|
|
``'800-2655328'``.
|
|
|
|
The input doesn't have to be a valid phone number. This will happily convert
|
|
any string.
|
|
|
|
pluralize
|
|
~~~~~~~~~
|
|
|
|
Returns a plural suffix if the value is not 1. By default, this suffix is ``'s'``.
|
|
|
|
Example::
|
|
|
|
You have {{ num_messages }} message{{ num_messages|pluralize }}.
|
|
|
|
For words that require a suffix other than ``'s'``, you can provide an alternate
|
|
suffix as a parameter to the filter.
|
|
|
|
Example::
|
|
|
|
You have {{ num_walruses }} walrus{{ num_walrus|pluralize:"es" }}.
|
|
|
|
For words that don't pluralize by simple suffix, you can specify both a
|
|
singular and plural suffix, separated by a comma.
|
|
|
|
Example::
|
|
|
|
You have {{ num_cherries }} cherr{{ num_cherries|pluralize:"y,ies" }}.
|
|
|
|
pprint
|
|
~~~~~~
|
|
|
|
A wrapper around pprint.pprint -- for debugging, really.
|
|
|
|
random
|
|
~~~~~~
|
|
|
|
Returns a random item from the list.
|
|
|
|
removetags
|
|
~~~~~~~~~~
|
|
|
|
Removes a space separated list of [X]HTML tags from the output.
|
|
|
|
rjust
|
|
~~~~~
|
|
|
|
Right-aligns the value in a field of a given width.
|
|
|
|
**Argument:** field size
|
|
|
|
slice
|
|
~~~~~
|
|
|
|
Returns a slice of the list.
|
|
|
|
Uses the same syntax as Python's list slicing. See
|
|
http://diveintopython.org/native_data_types/lists.html#odbchelper.list.slice
|
|
for an introduction.
|
|
|
|
Example: ``{{ some_list|slice:":2" }}``
|
|
|
|
slugify
|
|
~~~~~~~
|
|
|
|
Converts to lowercase, removes non-word characters (alphanumerics and
|
|
underscores) and converts spaces to hyphens. Also strips leading and trailing
|
|
whitespace.
|
|
|
|
stringformat
|
|
~~~~~~~~~~~~
|
|
|
|
Formats the variable according to the argument, a string formatting specifier.
|
|
This specifier uses Python string formating syntax, with the exception that
|
|
the leading "%" is dropped.
|
|
|
|
See http://docs.python.org/lib/typesseq-strings.html for documentation of
|
|
Python string formatting
|
|
|
|
striptags
|
|
~~~~~~~~~
|
|
|
|
Strips all [X]HTML tags.
|
|
|
|
time
|
|
~~~~
|
|
|
|
Formats a time according to the given format (same as the ``now`` tag).
|
|
|
|
timesince
|
|
~~~~~~~~~
|
|
|
|
Formats a date as the time since that date (i.e. "4 days, 6 hours").
|
|
|
|
Takes an optional argument that is a variable containing the date to use as
|
|
the comparison point (without the argument, the comparison point is *now*).
|
|
For example, if ``blog_date`` is a date instance representing midnight on 1
|
|
June 2006, and ``comment_date`` is a date instance for 08:00 on 1 June 2006,
|
|
then ``{{ comment_date|timesince:blog_date }}`` would return "8 hours".
|
|
|
|
timeuntil
|
|
~~~~~~~~~
|
|
|
|
Similar to ``timesince``, except that it measures the time from now until the
|
|
given date or datetime. For example, if today is 1 June 2006 and
|
|
``conference_date`` is a date instance holding 29 June 2006, then
|
|
``{{ conference_date|timeuntil }}`` will return "28 days".
|
|
|
|
Takes an optional argument that is a variable containing the date to use as
|
|
the comparison point (instead of *now*). If ``from_date`` contains 22 June
|
|
2006, then ``{{ conference_date|timeuntil:from_date }}`` will return "7 days".
|
|
|
|
title
|
|
~~~~~
|
|
|
|
Converts a string into titlecase.
|
|
|
|
truncatewords
|
|
~~~~~~~~~~~~~
|
|
|
|
Truncates a string after a certain number of words.
|
|
|
|
**Argument:** Number of words to truncate after
|
|
|
|
truncatewords_html
|
|
~~~~~~~~~~~~~~~~~~
|
|
|
|
Similar to ``truncatewords``, except that it is aware of HTML tags. Any tags
|
|
that are opened in the string and not closed before the truncation point, are
|
|
closed immediately after the truncation.
|
|
|
|
This is less efficient than ``truncatewords``, so should only be used when it
|
|
is being passed HTML text.
|
|
|
|
unordered_list
|
|
~~~~~~~~~~~~~~
|
|
|
|
Recursively takes a self-nested list and returns an HTML unordered list --
|
|
WITHOUT opening and closing <ul> tags.
|
|
|
|
The list is assumed to be in the proper format. For example, if ``var`` contains
|
|
``['States', [['Kansas', [['Lawrence', []], ['Topeka', []]]], ['Illinois', []]]]``,
|
|
then ``{{ var|unordered_list }}`` would return::
|
|
|
|
<li>States
|
|
<ul>
|
|
<li>Kansas
|
|
<ul>
|
|
<li>Lawrence</li>
|
|
<li>Topeka</li>
|
|
</ul>
|
|
</li>
|
|
<li>Illinois</li>
|
|
</ul>
|
|
</li>
|
|
|
|
upper
|
|
~~~~~
|
|
|
|
Converts a string into all uppercase.
|
|
|
|
urlencode
|
|
~~~~~~~~~
|
|
|
|
Escapes a value for use in a URL.
|
|
|
|
urlize
|
|
~~~~~~
|
|
|
|
Converts URLs in plain text into clickable links.
|
|
|
|
urlizetrunc
|
|
~~~~~~~~~~~
|
|
|
|
Converts URLs into clickable links, truncating URLs longer than the given
|
|
character limit.
|
|
|
|
**Argument:** Length to truncate URLs to
|
|
|
|
wordcount
|
|
~~~~~~~~~
|
|
|
|
Returns the number of words.
|
|
|
|
wordwrap
|
|
~~~~~~~~
|
|
|
|
Wraps words at specified line length.
|
|
|
|
**Argument:** number of characters at which to wrap the text
|
|
|
|
yesno
|
|
~~~~~
|
|
|
|
Given a string mapping values for true, false and (optionally) None,
|
|
returns one of those strings according to the value:
|
|
|
|
========== ====================== ==================================
|
|
Value Argument Outputs
|
|
========== ====================== ==================================
|
|
``True`` ``"yeah,no,maybe"`` ``yeah``
|
|
``False`` ``"yeah,no,maybe"`` ``no``
|
|
``None`` ``"yeah,no,maybe"`` ``maybe``
|
|
``None`` ``"yeah,no"`` ``"no"`` (converts None to False
|
|
if no mapping for None is given)
|
|
========== ====================== ==================================
|
|
|
|
Other tags and filter libraries
|
|
===============================
|
|
|
|
Django comes with a couple of other template-tag libraries that you have to
|
|
enable explicitly in your ``INSTALLED_APPS`` setting and enable in your
|
|
template with the ``{% load %}`` tag.
|
|
|
|
django.contrib.humanize
|
|
-----------------------
|
|
|
|
A set of Django template filters useful for adding a "human touch" to data. See
|
|
the `humanize documentation`_.
|
|
|
|
.. _humanize documentation: ../add_ons/#humanize
|
|
|
|
django.contrib.markup
|
|
---------------------
|
|
|
|
A collection of template filters that implement these common markup languages:
|
|
|
|
* Textile
|
|
* Markdown
|
|
* ReST (ReStructured Text)
|
|
|
|
django.contrib.webdesign
|
|
------------------------
|
|
|
|
A collection of template tags that can be useful while designing a website,
|
|
such as a generator of Lorem Ipsum text. See the `webdesign documentation`_.
|
|
|
|
.. _webdesign documentation: ../webdesign/
|