Your classes should not depend on any objects that are not either injected into the class or created in the class itself. If they do, you cannot ever change that dependency from outside, which reduces the flexibility and testability of the class.
If you use your class without having a context (f.i. in a task) you'll get the infamous error message that this thread is titled with. The problem is that this dependency is not visible from outside - there is no $context parameter in the constructor, nor a method ->setContext() or the like. Furthermore, no exception is thrown by the class itself that a context is required, thus the error is hard to debug. Regarding testability: In unit tests, you usually substitute most dependencies (the objects that the tested class depends on) by fake objects, that is, objects that act "as if" they were the real objects without having a real implementation. The benefit is that the test setup is much easier to do (imagine reading factories.yml before every unit test just because you need the context!), it runs much faster and it does not fail if the dependency is buggy (in that case, only the test for the dependency itself should fail). Now if your dependency is hardcoded in the class, you cannot ever substitute it by a fake implementation in the test. Thus, always inject all dependencies through the constructor (if they are required) or through a setter (if they are optional). If you want to learn more about dependency injection, I suggest to read Fabien's very good blog posts: http://fabien.potencier.org/article/11/what-is-dependency-injection Bernhard --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "symfony users" group. To post to this group, send email to symfony-users@googlegroups.com To unsubscribe from this group, send email to symfony-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/symfony-users?hl=en -~----------~----~----~----~------~----~------~--~---
