global_variables.rst

.. index::
   single: Templating; Global variables

Injecting variables into all templates (i.e. Global Variables)

Sometimes you want a variable to be accessible to all the templates you use. This is possible inside your app/config/config.yml file:

# app/config/config.yml
twig:
    # ...
    globals:
        ga_tracking: UA-xxxxx-x

Now, the variable ga_tracking is available in all Twig templates:

<p>Our google tracking code is: {{ ga_tracking }} </p>

It's that easy! You can also take advantage of the built-in :ref:`book-service-container-parameters` system, which lets you isolate or reuse the value:

; app/config/parameters.yml
[parameters]
    ga_tracking: UA-xxxxx-x

# app/config/config.yml
twig:
    globals:
        ga_tracking: %ga_tracking%

The same variable is available exactly as before.

More Complex Global Variables

If the global variable you want to set is more complicated - say an object - then you won't be able to use the above method. Instead, you'll need to create a :ref:`Twig Extension<reference-dic-tags-twig-extension>` and return the global variable as one of the entries in the getGlobals method.