
Templating
**********

Sphinx uses the Jinja templating engine for its HTML templates.  Jinja
is a text-based engine, and inspired by Django templates, so anyone
having used Django will already be familiar with it.  It also has
excellent documentation for those who need to make themselves familiar
with it.


Do I need to use Sphinx' templates to produce HTML?
===================================================

No.  You have several other options:

* You can write a ``TemplateBridge`` subclass that calls your template
  engine of choice, and set the ``template_bridge`` configuration
  value accordingly.

* You can *write a custom builder* that derives from
  ``StandaloneHTMLBuilder`` and calls your template engine of choice.

* You can use the ``PickleHTMLBuilder`` that produces pickle files
  with the page contents, and postprocess them using a custom tool, or
  use them in your Web application.


Jinja/Sphinx Templating Primer
==============================

The default templating language in Sphinx is Jinja.  It's
Django/Smarty inspired and easy to understand.  The most important
concept in Jinja is *template inheritance*, which means that you can
overwrite only specific blocks within a template, customizing it while
also keeping the changes at a minimum.

To customize the output of your documentation you can override all the
templates (both the layout templates and the child templates) by
adding files with the same name as the original filename into the
template directory of the structure the Sphinx quickstart generated
for you.

Sphinx will look for templates in the folders of ``templates_path``
first, and if it can't find the template it's looking for there, it
falls back to the selected theme's templates.

A template contains **variables**, which are replaced with values when
the template is evaluated, **tags**, which control the logic of the
template and **blocks** which are used for template inheritance.

Sphinx' *basic* theme provides base templates with a couple of blocks
it will fill with data.  These are located in the ``themes/basic``
subdirectory of the Sphinx installation directory, and used by all
builtin Sphinx themes. Templates with the same name in the
``templates_path`` override templates supplied by the selected theme.

For example, to add a new link to the template area containing related
links all you have to do is to add a new template called
``layout.html`` with the following contents:

   {% extends "!layout.html" %}
   {% block rootrellink %}
       <li><a href="http://project.invalid/">Project Homepage</a> &raquo;</li>
       {{ super() }}
   {% endblock %}

By prefixing the name of the overridden template with an exclamation
mark, Sphinx will load the layout template from the underlying HTML
theme.

**Important**: If you override a block, call ``{{ super() }}``
somewhere to render the block's content in the extended template --
unless you don't want that content to show up.


Working with the builtin templates
==================================

The builtin **basic** theme supplies the templates that all builtin
Sphinx themes are based on.  It has the following elements you can
override or use:


Blocks
------

The following blocks exist in the ``layout.html`` template:

*doctype*
   The doctype of the output format.  By default this is XHTML 1.0
   Transitional as this is the closest to what Sphinx and Docutils
   generate and it's a good idea not to change it unless you want to
   switch to HTML 5 or a different but compatible XHTML doctype.

*linktags*
   This block adds a couple of ``<link>`` tags to the head section of
   the template.

*extrahead*
   This block is empty by default and can be used to add extra
   contents into the ``<head>`` tag of the generated HTML file.  This
   is the right place to add references to JavaScript or extra CSS
   files.

*relbar1* / *relbar2*
   This block contains the *relation bar*, the list of related links
   (the parent documents on the left, and the links to index, modules
   etc. on the right).  *relbar1* appears before the document,
   *relbar2* after the document.  By default, both blocks are filled;
   to show the relbar only before the document, you would override
   *relbar2* like this:

      {% block relbar2 %}{% endblock %}

*rootrellink* / *relbaritems*
   Inside the relbar there are three sections: The *rootrellink*, the
   links from the documentation and the custom *relbaritems*.  The
   *rootrellink* is a block that by default contains a list item
   pointing to the master document by default, the *relbaritems* is an
   empty block.  If you override them to add extra links into the bar
   make sure that they are list items and end with the ``reldelim1``.

*document*
   The contents of the document itself.  It contains the block "body"
   where the individual content is put by subtemplates like
   ``page.html``.

*sidebar1* / *sidebar2*
   A possible location for a sidebar.  *sidebar1* appears before the
   document and is empty by default, *sidebar2* after the document and
   contains the default sidebar.  If you want to swap the sidebar
   location override this and call the *sidebar* helper:

      {% block sidebar1 %}{{ sidebar() }}{% endblock %}
      {% block sidebar2 %}{% endblock %}

   (The *sidebar2* location for the sidebar is needed by the
   ``sphinxdoc.css`` stylesheet, for example.)

*sidebarlogo*
   The logo location within the sidebar.  Override this if you want to
   place some content at the top of the sidebar.

*footer*
   The block for the footer div.  If you want a custom footer or
   markup before or after it, override this one.

The following four blocks are *only* used for pages that do not have
assigned a list of custom sidebars in the ``html_sidebars`` config
value.  Their use is deprecated in favor of separate sidebar
templates, which can be included via ``html_sidebars``.

*sidebartoc*
   The table of contents within the sidebar.

   Deprecated since version 1.0.

*sidebarrel*
   The relation links (previous, next document) within the sidebar.

   Deprecated since version 1.0.

*sidebarsourcelink*
   The "Show source" link within the sidebar (normally only shown if
   this is enabled by ``html_show_sourcelink``).

   Deprecated since version 1.0.

*sidebarsearch*
   The search box within the sidebar.  Override this if you want to
   place some content at the bottom of the sidebar.

   Deprecated since version 1.0.


Configuration Variables
-----------------------

Inside templates you can set a couple of variables used by the layout
template using the ``{% set %}`` tag:

reldelim1

   The delimiter for the items on the left side of the related bar.
   This defaults to ``' &raquo;'`` Each item in the related bar ends
   with the value of this variable.

reldelim2

   The delimiter for the items on the right side of the related bar.
   This defaults to ``' |'``.  Each item except of the last one in the
   related bar ends with the value of this variable.

Overriding works like this:

   {% extends "!layout.html" %}
   {% set reldelim1 = ' &gt;' %}

script_files

   Add additional script files here, like this:

      {% set script_files = script_files + [pathto("_static/myscript.js", 1)] %}


Helper Functions
----------------

Sphinx provides various Jinja functions as helpers in the template.
You can use them to generate links or output multiply used elements.

pathto(document)

   Return the path to a Sphinx document as a URL.  Use this to refer
   to built documents.

pathto(file, 1)

   Return the path to a *file* which is a filename relative to the
   root of the generated output.  Use this to refer to static files.

hasdoc(document)

   Check if a document with the name *document* exists.

sidebar()

   Return the rendered sidebar.

relbar()

   Return the rendered relation bar.


Global Variables
----------------

These global variables are available in every template and are safe to
use. There are more, but most of them are an implementation detail and
might change in the future.

builder

   The name of the builder (e.g. ``html`` or ``htmlhelp``).

copyright

   The value of ``copyright``.

docstitle

   The title of the documentation (the value of ``html_title``).

embedded

   True if the built HTML is meant to be embedded in some viewing
   application that handles navigation, not the web browser, such as
   for HTML help or Qt help formats.  In this case, the sidebar is not
   included.

favicon

   The path to the HTML favicon in the static path, or ``''``.

file_suffix

   The value of the builder's ``out_suffix`` attribute, i.e. the file
   name extension that the output files will get.  For a standard HTML
   builder, this is usually ``.html``.

has_source

   True if the reST document sources are copied (if
   ``html_copy_source`` is true).

last_updated

   The build date.

logo

   The path to the HTML logo image in the static path, or ``''``.

master_doc

   The value of ``master_doc``, for usage with ``pathto()``.

next

   The next document for the navigation.  This variable is either
   false or has two attributes *link* and *title*.  The title contains
   HTML markup.  For example, to generate a link to the next page, you
   can use this snippet:

      {% if next %}
      <a href="{{ next.link|e }}">{{ next.title }}</a>
      {% endif %}

pagename

   The "page name" of the current file, i.e. either the document name
   if the file is generated from a reST source, or the equivalent
   hierarchical name relative to the output directory
   (``[directory/]filename_without_extension``).

parents

   A list of parent documents for navigation, structured like the
   ``next`` item.

prev

   Like ``next``, but for the previous page.

project

   The value of ``project``.

release

   The value of ``release``.

rellinks

   A list of links to put at the left side of the relbar, next to
   "next" and "prev".  This usually contains links to the general
   index and other indices, such as the Python module index.  If you
   add something yourself, it must be a tuple ``(pagename, link title,
   accesskey, link text)``.

shorttitle

   The value of ``html_short_title``.

show_source

   True if ``html_show_sourcelink`` is true.

sphinx_version

   The version of Sphinx used to build.

style

   The name of the main stylesheet, as given by the theme or
   ``html_style``.

title

   The title of the current document, as used in the ``<title>`` tag.

use_opensearch

   The value of ``html_use_opensearch``.

version

   The value of ``version``.

In addition to these values, there are also all **theme options**
available (prefixed by ``theme_``), as well as the values given by the
user in ``html_context``.

In documents that are created from source files (as opposed to
automatically-generated files like the module index, or documents that
already are in HTML form), these variables are also available:

meta

   Document metadata (a dictionary), see *File-wide metadata*.

sourcename

   The name of the copied source file for the current document.  This
   is only nonempty if the ``html_copy_source`` value is true.

toc

   The local table of contents for the current page, rendered as HTML
   bullet lists.

toctree

   A callable yielding the global TOC tree containing the current
   page, rendered as HTML bullet lists.  Optional keyword arguments:

   * ``collapse`` (true by default): if true, all TOC entries that are
     not ancestors of the current page are collapsed

   * ``maxdepth`` (defaults to the max depth selected in the toctree
     directive): the maximum depth of the tree; set it to ``-1`` to
     allow unlimited depth

   * ``titles_only`` (false by default): if true, put only toplevel
     document titles in the tree
