在Symfony2中将Array的单个元素用作服务构造函数参数

Question

In the symfony2 docs at http://symfony.com/doc/current/components/dependency_injection/parameters.html it states that parameters (in service definitions) can be defined as arrays eg:

parameters:
    foo.class:"Foo"
    foo.args:
        - arg1
        - arg2

I want to know how to pass a single element of the foo.args array to the service constructor ie:

services:
    foo:
        class:"%foo.class%"
        arguments:["%foo.args.1%"] //this line is in question.does this resolve to
                                   //"arg1"?if not, what does?

Answer 1

Your current implementation won't work.

Internally symfony would try to access array['1'] (key=string) instead of array[1] (key=int).

Consider using a service factory that in turn creates the service with the desired element of the array as argument ...

... or just filter the array elements in the constructor of the class.