Template Tags
==============

:synopsis: Template Tags in django-boost


Python built-in functions
--------------------------

Make Python built-in functions available in DjangoTemplate.

Some non-built-in functions are also provided as filters.

An example is ``isiterable`` filter.

Usage
~~~~~~~~~~~~

::

  {% load boost %}

isiterable
~~~~~~~~~~~

``isiterable`` filter returns True if it filters repeatable objects, and False otherwise.

::

  {% load boost %}

  {% if object|isiterable %}
    {% for i in object %}
      <p>{{ i }}</p>
    {% endfor %}
  {% else %}
    <p>{{ object }}</p>
  {% endif %}


literal
~~~~~~~~

Python literal from string.
Using backend ``ast.literal_eval``.

::

  {% load boost %}

  {% literal "[1, 2, 3]" as list %}

  {% for i in list %}
      <p>{{ i }}</p>
  {% endfor %}

chain
~~~~~~~~
Concatenate iterable objects

::

  {% load boost %}

  {% chain list1 list2 as concatenated_list %}

  {% for i in concatenated_list %}
    {{ i }}
  {% endfor %}


chunked
~~~~~~~~
Break *iterable* into lists of length *n*

::

  {% load boost %}

  {% for i in list|chunked:3 %}
    {% for j in i %}
      {{ j }}
    {% endfor %}
  {% endfor %}


URL Utility
------------

Usage
~~~~~~~~~~~~

::

  {% load boost_url %}

urlencode
~~~~~~~~~~

URL encode the filtered string.
You can specify non-conversion characters in the argument.

::

  {% load boost_url %}

  {{ url | urlencode }}

  {{ url | urlencode:'abc' }}


urldecode
~~~~~~~~~~

The reverse of ``urlencode``.

::

  {% load boost_url %}

  {{ url | urldecode }}

replace_parameters
~~~~~~~~~~~~~~~~~~~

Replace the query string of the current page URL with the argument.

::

  {% load boost_url %}

  {# case of current page's query string is `?id=2`#}
  {% replace_parameters request 'id' 1 'age' 20 %}

  {# The result of replacing is `?id=1&age=20` #}

Useful for pagination.

get_querystring
~~~~~~~~~~~~~~~~

return querystring value

::

  {% load boost_url %}

  {% get_querystring request 'id' %}

  {# return request.GET.get('id', None) #}


Queryset Utility
-----------------

Usage
~~~~~~~~~~~~

::

  {% load boost_query %}

Make the query set methods available in the template.

``filter``, ``exclude``, ``order_by`` are available.

If you use the LogicalDeletionMixin, you can also use ``alive`` and ``dead``

::

  {% qureyset|filter:"field=value"%}

  {% qureyset|exclude:"field=value"%}

  {% qureyset|order_by:"field"%}

  {# If it inherits LogicalDeletionMixin. #}

  {% qureyset|alive %}

  {% qureyset|dead %}


MimeType Utility
-----------------

Usage
~~~~~~~~~~~~

::

  {% load mimetype %}

mimetype
~~~~~~~~~

Guess mimetype from the extension at the end of the string.

Python ``mimetypes.guess_type`` is used internally.

::

  {{ "json"|mimetype }} {# "application/json" #}

  {{ ".json"|mimetype }} {# "application/json" #}

  {{ "sample.json"|mimetype }} {# "application/json" #}