1 ==================================================
2 The Django template language: For template authors
3 ==================================================
5 Django's template language is designed to strike a balance between power and
6 ease. It's designed to feel comfortable to those used to working with HTML. If
7 you have any exposure to other text-based template languages, such as Smarty_
8 or CheetahTemplate_, you should feel right at home with Django's templates.
10 .. _Smarty: http://smarty.php.net/
11 .. _CheetahTemplate: http://www.cheetahtemplate.org/
16 A template is simply a text file. It can generate any text-based format (HTML,
19 A template contains **variables**, which get replaced with values when the
20 template is evaluated, and **tags**, which control the logic of the template.
22 Below is a minimal template that illustrates a few basics. Each element will be
23 explained later in this document.::
25 {% extends "base_generic.html" %}
27 {% block title %}{{ section.title }}{% endblock %}
30 <h1>{{ section.title }}</h1>
32 {% for story in story_list %}
34 <a href="{{ story.get_absolute_url }}">
35 {{ story.headline|upper }}
38 <p>{{ story.tease|truncatewords:"100" }}</p>
42 .. admonition:: Philosophy
44 Why use a text-based template instead of an XML-based one (like Zope's
45 TAL)? We wanted Django's template language to be usable for more than
46 just XML/HTML templates. At World Online, we use it for e-mails,
47 JavaScript and CSV. You can use the template language for any text-based
50 Oh, and one more thing: Making humans edit XML is sadistic!
55 Variables look like this: ``{{ variable }}``. When the template engine
56 encounters a variable, it evaluates that variable and replaces it with the
59 Use a dot (``.``) to access attributes of a variable.
61 .. admonition:: Behind the scenes
63 Technically, when the template system encounters a dot, it tries the
64 following lookups, in this order:
71 In the above example, ``{{ section.title }}`` will be replaced with the
72 ``title`` attribute of the ``section`` object.
74 If you use a variable that doesn't exist, the template system will insert
75 the value of the ``TEMPLATE_STRING_IF_INVALID`` setting, which is set to ``''``
76 (the empty string) by default.
78 See `Using the built-in reference`_, below, for help on finding what variables
79 are available in a given template.
84 You can modify variables for display by using **filters**.
86 Filters look like this: ``{{ name|lower }}``. This displays the value of the
87 ``{{ name }}`` variable after being filtered through the ``lower`` filter,
88 which converts text to lowercase. Use a pipe (``|``) to apply a filter.
90 Filters can be "chained." The output of one filter is applied to the next.
91 ``{{ text|escape|linebreaks }}`` is a common idiom for escaping text contents,
92 then converting line breaks to ``<p>`` tags.
94 Some filters take arguments. A filter argument looks like this: ``{{
95 bio|truncatewords:30 }}``. This will display the first 30 words of the ``bio``
98 Filter arguments that contain spaces must be quoted; for example, to join a list
99 with commas and spaced you'd use ``{{ list|join:", " }}``.
101 The `Built-in filter reference`_ below describes all the built-in filters.
106 Tags look like this: ``{% tag %}``. Tags are more complex than variables: Some
107 create text in the output, some control flow by performing loops or logic, and
108 some load external information into the template to be used by later variables.
110 Some tags require beginning and ending tags (i.e.
111 ``{% tag %} ... tag contents ... {% endtag %}``). The `Built-in tag reference`_
112 below describes all the built-in tags. You can create your own tags, if you
113 know how to write Python code.
118 To comment-out part of a line in a template, use the comment syntax: ``{# #}``.
120 For example, this template would render as ``'hello'``::
124 A comment can contain any template code, invalid or not. For example::
126 {# {% if foo %}bar{% else %} #}
128 This syntax can only be used for single-line comments (no newlines are
129 permitted between the ``{#`` and ``#}`` delimiters). If you need to comment
130 out a multiline portion of the template, see the ``comment`` tag, below__.
137 The most powerful -- and thus the most complex -- part of Django's template
138 engine is template inheritance. Template inheritance allows you to build a base
139 "skeleton" template that contains all the common elements of your site and
140 defines **blocks** that child templates can override.
142 It's easiest to understand template inheritance by starting with an example::
144 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
145 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
146 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
148 <link rel="stylesheet" href="style.css" />
149 <title>{% block title %}My amazing site{% endblock %}</title>
156 <li><a href="/">Home</a></li>
157 <li><a href="/blog/">Blog</a></li>
163 {% block content %}{% endblock %}
168 This template, which we'll call ``base.html``, defines a simple HTML skeleton
169 document that you might use for a simple two-column page. It's the job of
170 "child" templates to fill the empty blocks with content.
172 In this example, the ``{% block %}`` tag defines three blocks that child
173 templates can fill in. All the ``block`` tag does is to tell the template
174 engine that a child template may override those portions of the template.
176 A child template might look like this::
178 {% extends "base.html" %}
180 {% block title %}My amazing blog{% endblock %}
183 {% for entry in blog_entries %}
184 <h2>{{ entry.title }}</h2>
185 <p>{{ entry.body }}</p>
189 The ``{% extends %}`` tag is the key here. It tells the template engine that
190 this template "extends" another template. When the template system evaluates
191 this template, first it locates the parent -- in this case, "base.html".
193 At that point, the template engine will notice the three ``{% block %}`` tags
194 in ``base.html`` and replace those blocks with the contents of the child
195 template. Depending on the value of ``blog_entries``, the output might look
198 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
199 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
200 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
202 <link rel="stylesheet" href="style.css" />
203 <title>My amazing blog</title>
209 <li><a href="/">Home</a></li>
210 <li><a href="/blog/">Blog</a></li>
216 <p>This is my first entry.</p>
219 <p>This is my second entry.</p>
224 Note that since the child template didn't define the ``sidebar`` block, the
225 value from the parent template is used instead. Content within a ``{% block %}``
226 tag in a parent template is always used as a fallback.
228 You can use as many levels of inheritance as needed. One common way of using
229 inheritance is the following three-level approach:
231 * Create a ``base.html`` template that holds the main look-and-feel of your
233 * Create a ``base_SECTIONNAME.html`` template for each "section" of your
234 site. For example, ``base_news.html``, ``base_sports.html``. These
235 templates all extend ``base.html`` and include section-specific
237 * Create individual templates for each type of page, such as a news
238 article or blog entry. These templates extend the appropriate section
241 This approach maximizes code reuse and makes it easy to add items to shared
242 content areas, such as section-wide navigation.
244 Here are some tips for working with inheritance:
246 * If you use ``{% extends %}`` in a template, it must be the first template
247 tag in that template. Template inheritance won't work, otherwise.
249 * More ``{% block %}`` tags in your base templates are better. Remember,
250 child templates don't have to define all parent blocks, so you can fill
251 in reasonable defaults in a number of blocks, then only define the ones
252 you need later. It's better to have more hooks than fewer hooks.
254 * If you find yourself duplicating content in a number of templates, it
255 probably means you should move that content to a ``{% block %}`` in a
258 * If you need to get the content of the block from the parent template,
259 the ``{{ block.super }}`` variable will do the trick. This is useful
260 if you want to add to the contents of a parent block instead of
261 completely overriding it.
263 * For extra readability, you can optionally give a *name* to your
264 ``{% endblock %}`` tag. For example::
268 {% endblock content %}
270 In larger templates, this technique helps you see which ``{% block %}``
271 tags are being closed.
273 Finally, note that you can't define multiple ``{% block %}`` tags with the same
274 name in the same template. This limitation exists because a block tag works in
275 "both" directions. That is, a block tag doesn't just provide a hole to fill --
276 it also defines the content that fills the hole in the *parent*. If there were
277 two similarly-named ``{% block %}`` tags in a template, that template's parent
278 wouldn't know which one of the blocks' content to use.
280 Using the built-in reference
281 ============================
283 Django's admin interface includes a complete reference of all template tags and
284 filters available for a given site. To see it, go to your admin interface and
285 click the "Documentation" link in the upper right of the page.
287 The reference is divided into 4 sections: tags, filters, models, and views.
289 The **tags** and **filters** sections describe all the built-in tags (in fact,
290 the tag and filter references below come directly from those pages) as well as
291 any custom tag or filter libraries available.
293 The **views** page is the most valuable. Each URL in your site has a separate
294 entry here, and clicking on a URL will show you:
296 * The name of the view function that generates that view.
297 * A short description of what the view does.
298 * The **context**, or a list of variables available in the view's template.
299 * The name of the template or templates that are used for that view.
301 Each view documentation page also has a bookmarklet that you can use to jump
302 from any page to the documentation page for that view.
304 Because Django-powered sites usually use database objects, the **models**
305 section of the documentation page describes each type of object in the system
306 along with all the fields available on that object.
308 Taken together, the documentation pages should tell you every tag, filter,
309 variable and object available to you in a given template.
311 Custom tag and filter libraries
312 ===============================
314 Certain applications provide custom tag and filter libraries. To access them in
315 a template, use the ``{% load %}`` tag::
319 {% comment_form for blogs.entries entry.id with is_public yes %}
321 In the above, the ``load`` tag loads the ``comments`` tag library, which then
322 makes the ``comment_form`` tag available for use. Consult the documentation
323 area in your admin to find the list of custom libraries in your installation.
325 The ``{% load %}`` tag can take multiple library names, separated by spaces.
328 {% load comments i18n %}
330 Custom libraries and template inheritance
331 -----------------------------------------
333 When you load a custom tag or filter library, the tags/filters are only made
334 available to the current template -- not any parent or child templates along
335 the template-inheritance path.
337 For example, if a template ``foo.html`` has ``{% load comments %}``, a child
338 template (e.g., one that has ``{% extends "foo.html" %}``) will *not* have
339 access to the comments template tags and filters. The child template is
340 responsible for its own ``{% load comments %}``.
342 This is a feature for the sake of maintainability and sanity.
344 Built-in tag and filter reference
345 =================================
347 For those without an admin site available, reference for the stock tags and
348 filters follows. Because Django is highly customizable, the reference in your
349 admin should be considered the final word on what tags and filters are
350 available, and what they do.
352 Built-in tag reference
353 ----------------------
358 Define a block that can be overridden by child templates. See
359 `Template inheritance`_ for more information.
364 Ignore everything between ``{% comment %}`` and ``{% endcomment %}``
369 Cycle among the given strings each time this tag is encountered.
371 Within a loop, cycles among the given strings each time through the loop::
373 {% for o in some_list %}
374 <tr class="{% cycle row1,row2 %}">
379 Outside of a loop, give the values a unique name the first time you call it,
380 then use that name each successive time through::
382 <tr class="{% cycle row1,row2,row3 as rowcolors %}">...</tr>
383 <tr class="{% cycle rowcolors %}">...</tr>
384 <tr class="{% cycle rowcolors %}">...</tr>
386 You can use any number of values, separated by commas. Make sure not to put
387 spaces between the values -- only commas.
392 Output a whole load of debugging information, including the current context and
398 Signal that this template extends a parent template.
400 This tag can be used in two ways:
402 * ``{% extends "base.html" %}`` (with quotes) uses the literal value
403 ``"base.html"`` as the name of the parent template to extend.
405 * ``{% extends variable %}`` uses the value of ``variable``. If the variable
406 evaluates to a string, Django will use that string as the name of the
407 parent template. If the variable evaluates to a ``Template`` object,
408 Django will use that object as the parent template.
410 See `Template inheritance`_ for more information.
415 Filter the contents of the variable through variable filters.
417 Filters can also be piped through each other, and they can have arguments --
418 just like in variable syntax.
422 {% filter escape|lower %}
423 This text will be HTML-escaped, and will appear in all lowercase.
429 Outputs the first variable passed that is not False. Outputs nothing if all the
430 passed variables are False.
434 {% firstof var1 var2 var3 %}
436 This is equivalent to::
440 {% else %}{% if var2 %}
442 {% else %}{% if var3 %}
444 {% endif %}{% endif %}{% endif %}
449 Loop over each item in an array. For example, to display a list of athletes
450 provided in ``athlete_list``::
453 {% for athlete in athlete_list %}
454 <li>{{ athlete.name }}</li>
458 You can loop over a list in reverse by using ``{% for obj in list reversed %}``.
460 **New in Django development version**
461 If you need to loop over a list of lists, you can unpack the values
462 in eachs sub-list into a set of known names. For example, if your context contains
463 a list of (x,y) coordinates called ``points``, you could use the following
464 to output the list of points::
466 {% for x, y in points %}
467 There is a point at {{ x }},{{ y }}
470 This can also be useful if you need to access the items in a dictionary.
471 For example, if your context contained a dictionary ``data``, the following
472 would display the keys and values of the dictionary::
474 {% for key, value in data.items %}
475 {{ key }}: {{ value }}
478 The for loop sets a number of variables available within the loop:
480 ========================== ================================================
482 ========================== ================================================
483 ``forloop.counter`` The current iteration of the loop (1-indexed)
484 ``forloop.counter0`` The current iteration of the loop (0-indexed)
485 ``forloop.revcounter`` The number of iterations from the end of the
487 ``forloop.revcounter0`` The number of iterations from the end of the
489 ``forloop.first`` True if this is the first time through the loop
490 ``forloop.last`` True if this is the last time through the loop
491 ``forloop.parentloop`` For nested loops, this is the loop "above" the
493 ========================== ================================================
498 The ``{% if %}`` tag evaluates a variable, and if that variable is "true" (i.e.
499 exists, is not empty, and is not a false boolean value) the contents of the
502 {% if athlete_list %}
503 Number of athletes: {{ athlete_list|length }}
508 In the above, if ``athlete_list`` is not empty, the number of athletes will be
509 displayed by the ``{{ athlete_list|length }}`` variable.
511 As you can see, the ``if`` tag can take an optional ``{% else %}`` clause that
512 will be displayed if the test fails.
514 ``if`` tags may use ``and``, ``or`` or ``not`` to test a number of variables or
515 to negate a given variable::
517 {% if athlete_list and coach_list %}
518 Both athletes and coaches are available.
521 {% if not athlete_list %}
522 There are no athletes.
525 {% if athlete_list or coach_list %}
526 There are some athletes or some coaches.
529 {% if not athlete_list or coach_list %}
530 There are no athletes or there are some coaches (OK, so
531 writing English translations of boolean logic sounds
532 stupid; it's not our fault).
535 {% if athlete_list and not coach_list %}
536 There are some athletes and absolutely no coaches.
539 ``if`` tags don't allow ``and`` and ``or`` clauses within the same tag, because
540 the order of logic would be ambiguous. For example, this is invalid::
542 {% if athlete_list and coach_list or cheerleader_list %}
544 If you need to combine ``and`` and ``or`` to do advanced logic, just use nested
545 ``if`` tags. For example::
547 {% if athlete_list %}
548 {% if coach_list or cheerleader_list %}
549 We have athletes, and either coaches or cheerleaders!
553 Multiple uses of the same logical operator are fine, as long as you use the
554 same operator. For example, this is valid::
556 {% if athlete_list or coach_list or parent_list or teacher_list %}
561 Check if a value has changed from the last iteration of a loop.
563 The 'ifchanged' block tag is used within a loop. It has two possible uses.
565 1. Checks its own rendered contents against its previous state and only
566 displays the content if it has changed. For example, this displays a list of
567 days, only displaying the month if it changes::
569 <h1>Archive for {{ year }}</h1>
571 {% for date in days %}
572 {% ifchanged %}<h3>{{ date|date:"F" }}</h3>{% endifchanged %}
573 <a href="{{ date|date:"M/d"|lower }}/">{{ date|date:"j" }}</a>
576 2. If given a variable, check whether that variable has changed. For
577 example, the following shows the date every time it changes, but
578 only shows the hour if both the hour and the date has changed::
580 {% for date in days %}
581 {% ifchanged date.date %} {{ date.date }} {% endifchanged %}
582 {% ifchanged date.hour date.date %}
590 Output the contents of the block if the two arguments equal each other.
594 {% ifequal user.id comment.user_id %}
598 As in the ``{% if %}`` tag, an ``{% else %}`` clause is optional.
600 The arguments can be hard-coded strings, so the following is valid::
602 {% ifequal user.username "adrian" %}
606 It is only possible to compare an argument to template variables or strings.
607 You cannot check for equality with Python objects such as ``True`` or
608 ``False``. If you need to test if something is true or false, use the ``if``
614 Just like ``ifequal``, except it tests that the two arguments are not equal.
619 Loads a template and renders it with the current context. This is a way of
620 "including" other templates within a template.
622 The template name can either be a variable or a hard-coded (quoted) string,
623 in either single or double quotes.
625 This example includes the contents of the template ``"foo/bar.html"``::
627 {% include "foo/bar.html" %}
629 This example includes the contents of the template whose name is contained in
630 the variable ``template_name``::
632 {% include template_name %}
634 An included template is rendered with the context of the template that's
635 including it. This example produces the output ``"Hello, John"``:
637 * Context: variable ``person`` is set to ``"john"``.
640 {% include "name_snippet.html" %}
642 * The ``name_snippet.html`` template::
646 See also: ``{% ssi %}``.
651 Load a custom template tag set.
653 See `Custom tag and filter libraries`_ for more information.
658 Display the date, formatted according to the given string.
660 Uses the same format as PHP's ``date()`` function (http://php.net/date)
661 with some custom extensions.
663 Available format strings:
665 ================ ======================================== =====================
666 Format character Description Example output
667 ================ ======================================== =====================
668 a ``'a.m.'`` or ``'p.m.'`` (Note that ``'a.m.'``
669 this is slightly different than PHP's
670 output, because this includes periods
671 to match Associated Press style.)
672 A ``'AM'`` or ``'PM'``. ``'AM'``
673 b Month, textual, 3 letters, lowercase. ``'jan'``
675 d Day of the month, 2 digits with ``'01'`` to ``'31'``
677 D Day of the week, textual, 3 letters. ``'Fri'``
678 f Time, in 12-hour hours and minutes, ``'1'``, ``'1:30'``
679 with minutes left off if they're zero.
680 Proprietary extension.
681 F Month, textual, long. ``'January'``
682 g Hour, 12-hour format without leading ``'1'`` to ``'12'``
684 G Hour, 24-hour format without leading ``'0'`` to ``'23'``
686 h Hour, 12-hour format. ``'01'`` to ``'12'``
687 H Hour, 24-hour format. ``'00'`` to ``'23'``
688 i Minutes. ``'00'`` to ``'59'``
690 j Day of the month without leading ``'1'`` to ``'31'``
692 l Day of the week, textual, long. ``'Friday'``
693 L Boolean for whether it's a leap year. ``True`` or ``False``
694 m Month, 2 digits with leading zeros. ``'01'`` to ``'12'``
695 M Month, textual, 3 letters. ``'Jan'``
696 n Month without leading zeros. ``'1'`` to ``'12'``
697 N Month abbreviation in Associated Press ``'Jan.'``, ``'Feb.'``, ``'March'``, ``'May'``
698 style. Proprietary extension.
699 O Difference to Greenwich time in hours. ``'+0200'``
700 P Time, in 12-hour hours, minutes and ``'1 a.m.'``, ``'1:30 p.m.'``, ``'midnight'``, ``'noon'``, ``'12:30 p.m.'``
701 'a.m.'/'p.m.', with minutes left off
702 if they're zero and the special-case
703 strings 'midnight' and 'noon' if
704 appropriate. Proprietary extension.
705 r RFC 822 formatted date. ``'Thu, 21 Dec 2000 16:01:07 +0200'``
706 s Seconds, 2 digits with leading zeros. ``'00'`` to ``'59'``
707 S English ordinal suffix for day of the ``'st'``, ``'nd'``, ``'rd'`` or ``'th'``
709 t Number of days in the given month. ``28`` to ``31``
710 T Time zone of this machine. ``'EST'``, ``'MDT'``
712 w Day of the week, digits without ``'0'`` (Sunday) to ``'6'`` (Saturday)
714 W ISO-8601 week number of year, with ``1``, ``23``
715 weeks starting on Monday.
716 y Year, 2 digits. ``'99'``
717 Y Year, 4 digits. ``'1999'``
718 z Day of the year. ``0`` to ``365``
719 Z Time zone offset in seconds. The ``-43200`` to ``43200``
720 offset for timezones west of UTC is
721 always negative, and for those east of
722 UTC is always positive.
723 ================ ======================================== =====================
727 It is {% now "jS F Y H:i" %}
729 Note that you can backslash-escape a format string if you want to use the
730 "raw" value. In this example, "f" is backslash-escaped, because otherwise
731 "f" is a format string that displays the time. The "o" doesn't need to be
732 escaped, because it's not a format character::
734 It is the {% now "jS o\f F" %}
736 This would display as "It is the 4th of September".
741 Regroup a list of alike objects by a common attribute.
743 This complex tag is best illustrated by use of an example: say that ``people``
744 is a list of people represented by dictionaries with ``first_name``,
745 ``last_name``, and ``gender`` keys::
748 {'first_name': 'George', 'last_name': 'Bush', 'gender': 'Male'},
749 {'first_name': 'Bill', 'last_name': 'Clinton', 'gender': 'Male'},
750 {'first_name': 'Margaret', 'last_name': 'Thatcher', 'gender': 'Female'},
751 {'first_name': 'Condoleezza', 'last_name': 'Rice', 'gender': 'Female'},
752 {'first_name': 'Pat', 'last_name': 'Smith', 'gender': 'Unknown'},
755 ...and you'd like to display a hierarchical list that is ordered by gender,
767 You can use the ``{% regroup %}`` tag to group the list of people by gender.
768 The following snippet of template code would accomplish this::
770 {% regroup people by gender as gender_list %}
773 {% for gender in gender_list %}
774 <li>{{ gender.grouper }}
776 {% for item in gender.list %}
777 <li>{{ item.first_name }} {{ item.last_name }}</li>
784 Let's walk through this example. ``{% regroup %}`` takes three arguments: the
785 list you want to regroup, the attribute to group by, and the name of the
786 resulting list. Here, we're regrouping the ``people`` list by the ``gender``
787 attribute and calling the result ``gender_list``.
789 ``{% regroup %}`` produces a list (in this case, ``gender_list``) of
790 **group objects**. Each group object has two attributes:
792 * ``grouper`` -- the item that was grouped by (e.g., the string "Male" or
794 * ``list`` -- a list of all items in this group (e.g., a list of all people
797 Note that ``{% regroup %}`` does not order its input! Our example relies on
798 the fact that the ``people`` list was ordered by ``gender`` in the first place.
799 If the ``people`` list did *not* order its members by ``gender``, the regrouping
800 would naively display more than one group for a single gender. For example,
801 say the ``people`` list was set to this (note that the males are not grouped
805 {'first_name': 'Bill', 'last_name': 'Clinton', 'gender': 'Male'},
806 {'first_name': 'Pat', 'last_name': 'Smith', 'gender': 'Unknown'},
807 {'first_name': 'Margaret', 'last_name': 'Thatcher', 'gender': 'Female'},
808 {'first_name': 'George', 'last_name': 'Bush', 'gender': 'Male'},
809 {'first_name': 'Condoleezza', 'last_name': 'Rice', 'gender': 'Female'},
812 With this input for ``people``, the example ``{% regroup %}`` template code
813 above would result in the following output:
826 The easiest solution to this gotcha is to make sure in your view code that the
827 data is ordered according to how you want to display it.
829 Another solution is to sort the data in the template using the ``dictsort``
830 filter, if your data is in a list of dictionaries::
832 {% regroup people|dictsort:"gender" by gender as gender_list %}
837 Removes whitespace between HTML tags. This includes tab
838 characters and newlines.
844 <a href="foo/">Foo</a>
848 This example would return this HTML::
850 <p><a href="foo/">Foo</a></p>
852 Only space between *tags* is removed -- not space between tags and text. In
853 this example, the space around ``Hello`` won't be stripped::
864 Output the contents of a given file into the page.
866 Like a simple "include" tag, ``{% ssi %}`` includes the contents of another
867 file -- which must be specified using an absolute path -- in the current
870 {% ssi /home/html/ljworld.com/includes/right_generic.html %}
872 If the optional "parsed" parameter is given, the contents of the included
873 file are evaluated as template code, within the current context::
875 {% ssi /home/html/ljworld.com/includes/right_generic.html parsed %}
877 Note that if you use ``{% ssi %}``, you'll need to define
878 `ALLOWED_INCLUDE_ROOTS`_ in your Django settings, as a security measure.
880 See also: ``{% include %}``.
882 .. _ALLOWED_INCLUDE_ROOTS: ../settings/#allowed-include-roots
887 Output one of the syntax characters used to compose template tags.
889 Since the template system has no concept of "escaping", to display one of the
890 bits used in template tags, you must use the ``{% templatetag %}`` tag.
892 The argument tells which template bit to output:
894 ================== =======
896 ================== =======
898 ``closeblock`` ``%}``
899 ``openvariable`` ``{{``
900 ``closevariable`` ``}}``
903 ``opencomment`` ``{#``
904 ``closecomment`` ``#}``
905 ================== =======
910 **Note that the syntax for this tag may change in the future, as we make it more robust.**
912 Returns an absolute URL (i.e., a URL without the domain name) matching a given
913 view function and optional parameters. This is a way to output links without
914 violating the DRY principle by having to hard-code URLs in your templates::
916 {% url path.to.some_view arg1,arg2,name1=value1 %}
918 The first argument is a path to a view function in the format
919 ``package.package.module.function``. Additional arguments are optional and
920 should be comma-separated values that will be used as positional and keyword
921 arguments in the URL. All arguments required by the URLconf should be present.
923 For example, suppose you have a view, ``app_views.client``, whose URLconf
924 takes a client ID (here, ``client()`` is a method inside the views file
925 ``app_views.py``). The URLconf line might look like this::
927 ('^client/(\d+)/$', 'app_views.client')
929 If this app's URLconf is included into the project's URLconf under a path
932 ('^clients/', include('project_name.app_name.urls'))
934 ...then, in a template, you can create a link to this view like this::
936 {% url app_views.client client.id %}
938 The template tag will output the string ``/clients/client/123/``.
943 For creating bar charts and such, this tag calculates the ratio of a given value
944 to a maximum value, and then applies that ratio to a constant.
948 <img src="bar.gif" height="10" width="{% widthratio this_value max_value 100 %}" />
950 Above, if ``this_value`` is 175 and ``max_value`` is 200, the the image in the
951 above example will be 88 pixels wide (because 175/200 = .875; .875 * 100 = 87.5
952 which is rounded up to 88).
957 **New in Django development version**
959 Caches a complex variable under a simpler name. This is useful when accessing
960 an "expensive" method (e.g., one that hits the database) multiple times.
964 {% with business.employees.count as total %}
965 {{ total }} employee{{ total|pluralize }}
968 The populated variable (in the example above, ``total``) is only available
969 between the ``{% with %}`` and ``{% endwith %}`` tags.
971 Built-in filter reference
972 -------------------------
977 Adds the arg to the value.
982 Adds slashes. Useful for passing strings to JavaScript, for example.
988 Capitalizes the first character of the value.
993 Centers the value in a field of a given width.
998 Removes all values of arg from the given string.
1003 Formats a date according to the given format (same as the `now`_ tag).
1008 If value is unavailable, use given default.
1013 If value is ``None``, use given default.
1018 Takes a list of dictionaries, returns that list sorted by the key given in
1024 Takes a list of dictionaries, returns that list sorted in reverse order by the
1025 key given in the argument.
1030 Returns true if the value is divisible by the argument.
1035 Escapes a string's HTML. Specifically, it makes these replacements:
1037 * ``"&"`` to ``"&"``
1038 * ``<`` to ``"<"``
1039 * ``>`` to ``">"``
1040 * ``'"'`` (double quote) to ``'"'``
1041 * ``"'"`` (single quote) to ``'''``
1046 Format the value like a 'human-readable' file size (i.e. ``'13 KB'``,
1047 ``'4.1 MB'``, ``'102 bytes'``, etc).
1052 Returns the first item in a list.
1057 Replaces ampersands with ``&`` entities.
1062 When used without an argument, rounds a floating-point number to one decimal
1063 place -- but only if there's a decimal part to be displayed. For example:
1065 * ``36.123`` gets converted to ``36.1``
1066 * ``36.15`` gets converted to ``36.2``
1067 * ``36`` gets converted to ``36``
1069 If used with a numeric integer argument, ``floatformat`` rounds a number to that
1070 many decimal places. For example:
1072 * ``36.1234`` with floatformat:3 gets converted to ``36.123``
1073 * ``36`` with floatformat:4 gets converted to ``36.0000``
1075 If the argument passed to ``floatformat`` is negative, it will round a number to
1076 that many decimal places -- but only if there's a decimal part to be displayed.
1079 * ``36.1234`` with floatformat:-3 gets converted to ``36.123``
1080 * ``36`` with floatformat:-4 gets converted to ``36``
1082 Using ``floatformat`` with no argument is equivalent to using ``floatformat`` with
1083 an argument of ``-1``.
1088 Given a whole number, returns the requested digit of it, where 1 is the
1089 right-most digit, 2 is the second-right-most digit, etc. Returns the original
1090 value for invalid input (if input or argument is not an integer, or if argument
1091 is less than 1). Otherwise, output is always an integer.
1096 Converts an IRI (Internationalized Resource Identifier) to a string that is
1097 suitable for including in a URL. This is necessary if you're trying to use
1098 strings containing non-ASCII characters in a URL.
1100 It's safe to use this filter on a string that has already gone through the
1101 ``urlencode`` filter.
1106 Joins a list with a string, like Python's ``str.join(list)``.
1111 Returns the length of the value. Useful for lists.
1116 Returns a boolean of whether the value's length is the argument.
1121 Converts newlines into ``<p>`` and ``<br />`` tags.
1126 Converts newlines into ``<br />`` tags.
1131 Displays text with line numbers.
1136 Left-aligns the value in a field of a given width.
1138 **Argument:** field size
1143 Converts a string into all lowercase.
1148 Returns the value turned into a list. For an integer, it's a list of
1149 digits. For a string, it's a list of characters.
1154 Converts a phone number (possibly containing letters) to its numerical
1155 equivalent. For example, ``'800-COLLECT'`` will be converted to
1158 The input doesn't have to be a valid phone number. This will happily convert
1164 Returns a plural suffix if the value is not 1. By default, this suffix is ``'s'``.
1168 You have {{ num_messages }} message{{ num_messages|pluralize }}.
1170 For words that require a suffix other than ``'s'``, you can provide an alternate
1171 suffix as a parameter to the filter.
1175 You have {{ num_walruses }} walrus{{ num_walrus|pluralize:"es" }}.
1177 For words that don't pluralize by simple suffix, you can specify both a
1178 singular and plural suffix, separated by a comma.
1182 You have {{ num_cherries }} cherr{{ num_cherries|pluralize:"y,ies" }}.
1187 A wrapper around pprint.pprint -- for debugging, really.
1192 Returns a random item from the list.
1197 Removes a space separated list of [X]HTML tags from the output.
1202 Right-aligns the value in a field of a given width.
1204 **Argument:** field size
1209 Returns a slice of the list.
1211 Uses the same syntax as Python's list slicing. See
1212 http://diveintopython.org/native_data_types/lists.html#odbchelper.list.slice
1213 for an introduction.
1215 Example: ``{{ some_list|slice:":2" }}``
1220 Converts to lowercase, removes non-word characters (alphanumerics and
1221 underscores) and converts spaces to hyphens. Also strips leading and trailing
1227 Formats the variable according to the argument, a string formatting specifier.
1228 This specifier uses Python string formating syntax, with the exception that
1229 the leading "%" is dropped.
1231 See http://docs.python.org/lib/typesseq-strings.html for documentation of
1232 Python string formatting
1237 Strips all [X]HTML tags.
1242 Formats a time according to the given format (same as the `now`_ tag).
1243 The time filter will only accept parameters in the format string that relate
1244 to the time of day, not the date (for obvious reasons). If you need to
1245 format a date, use the `date`_ filter.
1250 Formats a date as the time since that date (i.e. "4 days, 6 hours").
1252 Takes an optional argument that is a variable containing the date to use as
1253 the comparison point (without the argument, the comparison point is *now*).
1254 For example, if ``blog_date`` is a date instance representing midnight on 1
1255 June 2006, and ``comment_date`` is a date instance for 08:00 on 1 June 2006,
1256 then ``{{ comment_date|timesince:blog_date }}`` would return "8 hours".
1261 Similar to ``timesince``, except that it measures the time from now until the
1262 given date or datetime. For example, if today is 1 June 2006 and
1263 ``conference_date`` is a date instance holding 29 June 2006, then
1264 ``{{ conference_date|timeuntil }}`` will return "28 days".
1266 Takes an optional argument that is a variable containing the date to use as
1267 the comparison point (instead of *now*). If ``from_date`` contains 22 June
1268 2006, then ``{{ conference_date|timeuntil:from_date }}`` will return "7 days".
1273 Converts a string into titlecase.
1278 Truncates a string after a certain number of words.
1280 **Argument:** Number of words to truncate after
1285 Similar to ``truncatewords``, except that it is aware of HTML tags. Any tags
1286 that are opened in the string and not closed before the truncation point, are
1287 closed immediately after the truncation.
1289 This is less efficient than ``truncatewords``, so should only be used when it
1290 is being passed HTML text.
1295 Recursively takes a self-nested list and returns an HTML unordered list --
1296 WITHOUT opening and closing <ul> tags.
1298 The list is assumed to be in the proper format. For example, if ``var`` contains
1299 ``['States', [['Kansas', [['Lawrence', []], ['Topeka', []]]], ['Illinois', []]]]``,
1300 then ``{{ var|unordered_list }}`` would return::
1317 Converts a string into all uppercase.
1322 Escapes a value for use in a URL.
1327 Converts URLs in plain text into clickable links.
1329 Note that if ``urlize`` is applied to text that already contains HTML markup,
1330 things won't work as expected. Apply this filter only to *plain* text.
1335 Converts URLs into clickable links, truncating URLs longer than the given
1338 As with urlize_, this filter should only be applied to *plain* text.
1340 **Argument:** Length to truncate URLs to
1345 Returns the number of words.
1350 Wraps words at specified line length.
1352 **Argument:** number of characters at which to wrap the text
1357 Given a string mapping values for true, false and (optionally) None,
1358 returns one of those strings according to the value:
1360 ========== ====================== ==================================
1361 Value Argument Outputs
1362 ========== ====================== ==================================
1363 ``True`` ``"yeah,no,maybe"`` ``yeah``
1364 ``False`` ``"yeah,no,maybe"`` ``no``
1365 ``None`` ``"yeah,no,maybe"`` ``maybe``
1366 ``None`` ``"yeah,no"`` ``"no"`` (converts None to False
1367 if no mapping for None is given)
1368 ========== ====================== ==================================
1370 Other tags and filter libraries
1371 ===============================
1373 Django comes with a couple of other template-tag libraries that you have to
1374 enable explicitly in your ``INSTALLED_APPS`` setting and enable in your
1375 template with the ``{% load %}`` tag.
1377 django.contrib.humanize
1378 -----------------------
1380 A set of Django template filters useful for adding a "human touch" to data. See
1381 the `humanize documentation`_.
1383 .. _humanize documentation: ../add_ons/#humanize
1385 django.contrib.markup
1386 ---------------------
1388 A collection of template filters that implement these common markup languages:
1392 * ReST (ReStructured Text)
1394 django.contrib.webdesign
1395 ------------------------
1397 A collection of template tags that can be useful while designing a website,
1398 such as a generator of Lorem Ipsum text. See the `webdesign documentation`_.
1400 .. _webdesign documentation: ../webdesign/