vendor/twig/twig/doc/functions/dump.rst

   1 ``dump``
   2 ========
   3
   4 .. versionadded:: 1.5
   5     The dump function was added in Twig 1.5.
   6
   7 The ``dump`` function dumps information about a template variable. This is
   8 mostly useful to debug a template that does not behave as expected by
   9 introspecting its variables:
  10
  11 .. code-block:: jinja
  12
  13     {{ dump(user) }}
  14
  15 .. note::
  16
  17     The ``dump`` function is not available by default. You must add the
  18     ``Twig_Extension_Debug`` extension explicitly when creating your Twig
  19     environment::
  20
  21         $twig = new Twig_Environment($loader, array(
  22             'debug' => true,
  23             // ...
  24         ));
  25         $twig->addExtension(new Twig_Extension_Debug());
  26
  27     Even when enabled, the ``dump`` function won't display anything if the
  28     ``debug`` option on the environment is not enabled (to avoid leaking debug
  29     information on a production server).
  30
  31 In an HTML context, wrap the output with a ``pre`` tag to make it easier to
  32 read:
  33
  34 .. code-block:: jinja
  35
  36     <pre>
  37         {{ dump(user) }}
  38     </pre>
  39
  40 .. tip::
  41
  42     Using a ``pre`` tag is not needed when `XDebug`_ is enabled and
  43     ``html_errors`` is ``on``; as a bonus, the output is also nicer with
  44     XDebug enabled.
  45
  46 You can debug several variables by passing them as additional arguments:
  47
  48 .. code-block:: jinja
  49
  50     {{ dump(user, categories) }}
  51
  52 If you don't pass any value, all variables from the current context are
  53 dumped:
  54
  55 .. code-block:: jinja
  56
  57     {{ dump() }}
  58
  59 .. note::
  60
  61     Internally, Twig uses the PHP `var_dump`_ function.
  62
  63 Arguments
  64 ---------
  65
  66  * ``context``: The context to dump
  67
  68 .. _`XDebug`:   http://xdebug.org/docs/display
  69 .. _`var_dump`: http://php.net/var_dump