[1.7.x] Fixed #23984 -- Added Javascript i18n documentation

    <script type="text/javascript" src="{% url 'django.views.i18n.javascript_catalog' %}"></script>

This uses reverse URL lookup to find the URL of the JavaScript catalog view.

When the catalog is loaded, your JavaScript code can use the standard

``gettext`` interface to access it::

When the catalog is loaded, your JavaScript code can use the following methods:

* ``gettext``

* ``ngettext``

* ``interpolate``

* ``get_format``

* ``gettext_noop``

* ``pgettext``

* ``npgettext``

* ``pluralidx``

``gettext``

~~~~~~~~~~~

The ``gettext`` function behaves similarly to the standard ``gettext``

interface within your Python code::

    document.write(gettext('this is to be translated'));

There is also an ``ngettext`` interface::

``ngettext``

~~~~~~~~~~~~

The ``ngettext`` function provides an interface to pluralize words and

phrases::

    var object_cnt = 1 // or 0, or 2, or 3, ...

    s = ngettext('literal for the singular case',

            'literal for the plural case', object_cnt);

and even a string interpolation function::

    function interpolate(fmt, obj, named);

``interpolate``

~~~~~~~~~~~~~~~

The ``interpolate`` function supports dynamically populating a format string.

The interpolation syntax is borrowed from Python, so the ``interpolate``

function supports both positional and named interpolation:

    // s is 'There are 11 objects. Remaining: 20'

* Named interpolation: This mode is selected by passing the optional

  boolean ``named`` parameter as true. ``obj`` contains a JavaScript

  boolean ``named`` parameter as ``true``. ``obj`` contains a JavaScript

  object or associative array. For example::

    d = {

cases where you really need it (for example, in conjunction with ``ngettext``

to produce proper pluralizations).

``get_format``

~~~~~~~~~~~~~~

The ``get_format`` function has access to the configured i18n formatting

settings and can retrieve the format string for a given setting name::

    document.write(get_format('DATE_FORMAT'));

    // 'N j, Y'

It has access to the following settings:

* :setting:`DATE_FORMAT`

* :setting:`DATE_INPUT_FORMATS`

* :setting:`DATETIME_FORMAT`

* :setting:`DATETIME_INPUT_FORMATS`

* :setting:`DECIMAL_SEPARATOR`

* :setting:`FIRST_DAY_OF_WEEK`

* :setting:`MONTH_DAY_FORMAT`

* :setting:`NUMBER_GROUPING`

* :setting:`SHORT_DATE_FORMAT`

* :setting:`SHORT_DATETIME_FORMAT`

* :setting:`THOUSAND_SEPARATOR`

* :setting:`TIME_FORMAT`

* :setting:`TIME_INPUT_FORMATS`

* :setting:`YEAR_MONTH_FORMAT`

This is useful for maintaining formatting consistency with the Python-rendered

values.

``gettext_noop``

~~~~~~~~~~~~~~~~

This emulates the ``gettext`` function but does nothing, returning whatever

is passed to it::

    document.write(gettext_noop('this will not be translated'));

This is useful for stubbing out portions of the code that will need translation

in the future.

``pgettext``

~~~~~~~~~~~~

The ``pgettext`` function behaves like the Python variant

(:func:`~django.utils.translation.pgettext()`), providing a contextually

translated word::

    document.write(pgettext('month name', 'May'));

``npgettext``

~~~~~~~~~~~~~

The ``npgettext`` function also behaves like the Python variant

(:func:`~django.utils.translation.npgettext()`), providing a **pluralized**

contextually translated word::

    document.write(npgettext('group', 'party', 1));

    // party

    document.write(npgettext('group', 'party', 2));

    // parties

``pluralidx``

~~~~~~~~~~~~~

The ``pluralidx`` function works in a similar way to the :tfilter:`pluralize`

template filter, determining if a given ``count`` should use a plural form of

a word or not::

    document.write(pluralidx(0));

    // true

    document.write(pluralidx(1));

    // false

    document.write(pluralidx(2));

    // true

In the simplest case, if no custom pluralization is needed, this returns

``false`` for the integer ``1`` and ``true`` for all other numbers.

However, pluralization is not this simple in all languages. If the language does

not support pluralization, an empty value is provided.

Additionally, if there are complex rules around pluralization, the catalog view

will render a conditional expression. This will evaluate to either a ``true``

(should pluralize) or ``false`` (should **not** pluralize) value.

Note on performance

-------------------