How to get config parameters in Symfony2 Twig Templates

On newer versions of Symfony2 (using a parameters.yml instead of parameters.ini), you can store objects or arrays instead of key-value pairs, so you can manage your globals this way:

config.yml (edited only once):

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

parameters.yml:

# app/config/parameters.yml
project:
  name:       myproject.com
  version:    1.1.42

And then in a twig file, you can use {{ project.version }} or {{ project.name }}.

Note: I personally dislike adding things to app, just because that's the Symfony's variable and I don't know what will be stored there in the future.

You can use parameter substitution in the twig globals section of the config:

Parameter config:

parameters:
    app.version: 0.1.0

Twig config:

twig:
    globals:
        version: '%app.version%'

Twig template:

{{ version }}

This method provides the benefit of allowing you to use the parameter in ContainerAware classes as well, using:

$container->getParameter('app.version');

You can also take advantage of the built-in Service 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%"

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

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

The parameter is also available inside the controllers:

$this->container->getParameter('ga_tracking');

You can also define a service as a global Twig variable (Symfony2.2+):

# app/config/config.yml
twig:
    # ...
    globals:
        user_management: "@acme_user.user_management"

http://symfony.com/doc/current/templating/global_variables.html

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 Twig Extension and return the global variable as one of the entries in the getGlobals method.

Easily, you can define in your config file:

twig:
    globals:
        version: "0.1.0"

And access it in your template with

{{ version }}

Otherwise it must be a way with an Twig extension to expose your parameters.