Silverstripe在Injector中查找类，以便可以通过依赖注入覆盖类

Question

According to the Silverstripe documentation:

Using the create() method provides chainability, which can add elegance and brevity to your code, e.g. Player::create()->write(). More importantly, however, it will look up the class in the Injector so that the class can be overriden by dependency injection.

Can somebody explain the "it will look up the class in the Injector so that the class can be overridden by dependency injection" part?

Answer 1

When your Player Class depends on AnotherClass it is good practice to pass an instance of AnotherClass to Player. You can read more about this here: What is dependency injection?

SilverStripe has a build in Solution for Dependecy Injection: The Injector Class. See https://docs.silverstripe.org/en/3.3/developer_guides/extending/injector/

So when you call Player::create(); SilverStripe will look up the correct Class to use (defaults to Player Class but can be overridden with config files), create a new instance of it, inject its Dependencies and return that to you.

If you are new to SilverStripe you can probably ignore all that.