Sometimes you want a variable to be accessible to all the templates you use. This is possible inside your app/config/config.yml file:
有时您希望有个变量能够被您所使用的所有模板访问，这可以在您app/config/config.yml文件中设定：
- # app/config/config.yml
- twig:
- # ...
- globals:
- ga_tracking: UA-xxxxx-x
Now, the variable ga_tracking is available in all Twig templates:
现在，变量ga_tracking可以被所有Twig模板访问：
- <p>Our google tracking code is: {{ ga_tracking }} </p>
It's that easy! You can also take advantage of the built-in Service Parameters system, which lets you isolate or reuse the value:
这很容易！您也可以利用内建的服务参数系统，该系统可以让您隔离或重用该值：
- ; 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.
该变量同先前完全相同。
More Complex Global Variables
更复杂的全局变量
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.
如果您要设置的全局变量更复杂（如一个对象），那么您将无法使用上述方法。相反，您需要创建一个Twig扩展并返回全局变量。该全局变量作为getGlobals方法返回的全局变量列表中的成员。
本文转自 firehare 51CTO博客，原文链接：http://blog.51cto.com/firehare/1008587，如需转载请自行联系原作者
