@@ -41,7 +41,50 @@ Now, the variable ``ga_tracking`` is available in all Twig templates:
4141
4242 <p>The google tracking code is: {{ ga_tracking }}</p>
4343
44- It's that easy! You can also take advantage of the built-in:ref: `book-service-container-parameters `
44+ It's that easy!
45+
46+ Referencing Services
47+ --------------------
48+
49+ Instead of using static values, you can also set the value to a service.
50+ Whenever the global variabele is accessed in the template, the service will be
51+ requested from the service container and you get access to that object.
52+
53+ This is done by prefixing the string with ``@ ``, which you already know from
54+ injecting a service:
55+
56+ ..configuration-block ::
57+
58+ ..code-block ::yaml
59+
60+ # app/config/config.yml
61+ twig :
62+ # ...
63+ globals :
64+ user_management :" @acme_user.user_management"
65+
66+ code-block ::xml
67+
68+ <!-- app/config/config.xml-->
69+ <twig : config ...>
70+ <!-- ...-->
71+ <twig : global key =" user_management" twig : global >
72+ </twig : config >
73+
74+ code-block ::php
75+
76+ // app/config/config.php
77+ $container->loadFromExtension('twig', array(
78+ // ...
79+ 'globals' => array(
80+ 'user_management' => '@acme_user.user_management',
81+ ),
82+ ));
83+
84+
85+ ----------------------------------
86+
87+ You can also take advantage of the built-in:ref: `book-service-container-parameters `
4588system, which lets you isolate or reuse the value:
4689
4790..code-block ::yaml
@@ -77,8 +120,8 @@ system, which lets you isolate or reuse the value:
77120
78121
79122
80- More Complex Global Variables
81- -----------------------------
123+ Using a Twig Extension
124+ ----------------------
82125
83126If the global variable you want to set is more complicated - say an object -
84127then you won't be able to use the above method. Instead, you'll need to create