``dump``
========

The ``dump`` function dumps information about a template variable. This is
mostly useful to debug a template that does not behave as expected by
introspecting its variables:

.. code-block:: twig

    {{ dump(user) }}

.. note::

    The ``dump`` function is not available by default. You must add the
    ``\Twig\Extension\DebugExtension`` extension explicitly when creating your Twig
    environment::

        $twig = new \Twig\Environment($loader, [
            'debug' => true,
            // ...
        ]);
        $twig->addExtension(new \Twig\Extension\DebugExtension());

    Even when enabled, the ``dump`` function won't display anything if the
    ``debug`` option on the environment is not enabled (to avoid leaking debug
    information on a production server).

In an HTML context, wrap the output with a ``pre`` tag to make it easier to
read:

.. code-block:: twig

    <pre>
        {{ dump(user) }}
    </pre>

.. tip::

    Using a ``pre`` tag is not needed when `XDebug`_ is enabled and
    ``html_errors`` is ``on``; as a bonus, the output is also nicer with
    XDebug enabled.

You can debug several variables by passing them as additional arguments:

.. code-block:: twig

    {{ dump(user, categories) }}

If you don't pass any value, all variables from the current context are
dumped:

.. code-block:: twig

    {{ dump() }}

.. note::

    Internally, Twig uses the PHP `var_dump`_ function.

Arguments
---------

* ``context``: The context to dump

.. _`XDebug`:   https://xdebug.org/docs/display
.. _`var_dump`: https://secure.php.net/var_dump