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Javascript
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The "javascript" template tag library provides 3 template tags:
* javascript_assign: registers some Javascript code. Requires a
{% endjavascript_assign %} closing tag.
* javascript_render: displays all registered Javascript code
* javascript_reset: empties the Javascript registry
This template tag library has been written to help template designers implement
the following pattern:
* in templates, write Javascript fragments along with the corresponding HTML
code. This is done with the {% javascript_assign %} template tag.
* display the Javascript code at the end of the HTML document. This is done
by calling the {% javascript_render %} template tag at the end of the HTML
document.
* remove duplicate code fragments, e.g. do not call the same library twice.
This is done by the {% javascript_render %} template tag. Notice that, at
this time, only *strict* duplicates are ignored (i.e. if two Javascript
fragments have whitespace or attributes order differences, they won't be
considered as duplicate, even if they have the same meaning), so you may
have to respect some coding conventions about Javascript.
The main advantage of this template tag is that you can manage Javascript code
on a per-template basis. You no longer have to maintain both a specific
template for HTML code and a global template for all Javascript calls.
Let's review an example. We have 3 templates:
* base.html: the base template
* menu.html: include that display menus
* home.html: called when requesting / URL
base.html, template code:
.. code-block:: django
{% load javascript %}
{% javascript_assign %}{% endjavascript_assign %}
{% javascript_assign %}
{% endjavascript_assign %}
{% block content %}{% endblock content %}
{% javascript_render %}
menu.html, template code:
.. code-block:: django
{% load javascript %}
{% javascript_assign %}{% endjavascript_assign %}
{% javascript_assign %}
{% endjavascript_assign %}
home.html, template code:
.. code-block:: django
{% extends "base.html" %}
{% load javascript %}
{% block content %}
{% javascript_assign %}{% endjavascript_assign %}
{% javascript_assign %}{% endjavascript_assign %}
{% javascript_assign %}
{% endjavascript_assign %}
This is the content
{% endblock content %}
HTML output when requesting / URL (indentation and linebreaks have been
cleaned for improved lisibility):
.. code-block:: html
As you can see in the example above, the content of each {% javascript_assign %}
block has been saved. Then the {% javascript_render %} call removes duplicates
and displays all the code fragments, by order of appearance.
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javascript_assign
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Use it as container of each Javascript code fragment needed in your templates.
You should create separate {% javascript_assign %} blocks for each call to a
Javascript library.
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javascript_render
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Use it to render the Javascript code fragments *previously* registered in
{% javascript_assign %} blocks.
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javascript_reset
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Call it to empty the Javascript code fragments *previously* registered in
{% javascript_assign %} blocks. In general use case, you display Javascript
code once, so you do not need to use this tag.