docs/src/altsyntax.txt

==================
Alternative Syntax
==================

Jinja allows some syntax customization for the block delimiters. Depending on
the Jinja release more or less combinations are possible. The idea of an
customizable syntax is that you can update existing templates from other
template engines and programming languages easier and that you can replace
the django like default delimiters which are not everybody's favorite.


Configuring The Environment
===========================

For syntax configuration there are six arguments in the environment which
are the first six for convenience. Thus those two snippets do the same:

.. sourcecode:: python

    env = Environment(
         block_start_string='{%',
         block_end_string='%}',
         variable_start_string='{{',
         variable_end_string='}}',
         comment_start_string='{#',
         comment_end_string='#}',
    )

    env = Environment('{%', '%}', '{{', '}}', '{#', '#]')


Ruby Like Syntax
----------------

Here an example configuration for Ruby-like syntax:

.. sourcecode:: python

    env = Environment('<%', '%>', '<%=', '%>', '<%#', '%>')

An example template then looks like this:

.. sourcecode:: rhtml

    <%# example eruby like configuration for jinja %>
    <ul>
    <% for item in seq %>
      <li><%= item %></li>
    <% endfor %>
    </ul>


SGML Comment Syntax
-------------------

Here an example configuration that uses SGML comments to hide the
processing instructions. This can be useful if you work with an WYSIWYG
designer:

.. sourcecode:: python

    env = Environment('<!--', '-->', '${', '}', '<!--#', '-->')

.. sourcecode:: html

    <!--# example eruby like configuration for jinja -->
    <ul>
    <!-- for item in seq -->
      <li>${item}</li>
    <!-- endfor -->
    </ul>


Parenthesis Balancing
---------------------

Starting with Jinja 1.1 it's possible to use the block delimiter as a token
in the expression. That means that you can use small delimiters like single
braces or parenthesis. So if you want to have your variables to look like
``${expr}`` and you still want to use dicts in such expressions you need
Jinja 1.1 or higher.