Dependency Injection vs Factory Container

Showing differences between Dependency Injection and Service Locator (factory container)

What's the difference?

Service Locator

• Only defined services (Just knows about what it's told to know about)
• Have to configure everything manually

Dependency Injection

• Inspects constructor of classes in order to inject new instances of required parameters
• Uses Reflection to do this at the time the item is requested

Show our three layered classes and class requiring configuration

Service Locator

• Show initial Service Locator Container Bootstrap
• Weep at the amount of work just to instantiate a single complex object :(
• Run run-sl

Dependency Injection

• Show DI Container Bootstrap
• Totes Amazeballs - its so simple!
• Obviously need to write more code, no?
• Run run-di
• Profit

Oh wait, I need to configure something?

• Coding time!

What if my constructor requires an interface?

• More coding

What if I want an instance to be shared and not instantiated every time?

• So much more coding