Endovena: a dependency injection framework.

[Gary Willoughby via Digitalmars-d-announce]

On Saturday, 1 November 2014 at 16:36:02 UTC, JN wrote:
> I may be ignorant, can someone explain what's the difference 
> between:
>
> Container container;
> container.register!(IGreeter, Greeter);
> auto greeter = container.get!IGreeter();
> writefln(greeter.greet)
>
> and
>
> auto greeter = new Greeter();
> writefln(greeter.greet)
>
> ?

It's the fundamental way dependency injection containers are 
used. Instead of having complex dependencies on other resources 
you can just rely on the container to serve resources as needed.

For example if you have a class which needs the Greeter service 
you will either have to embed that service using composition or 
pass it into the class via a constructor or setter. A container 
is a single place where this and many other services can be 
retrieved. This also means that anything wanting to use the 
container is also dependent on it but this is sometimes less 
complicated than dealing with all the other dependencies 
individually. Also some dependencies have complicated rules for 
creating them which some dependency injection containers deal 
with, again removing this code from where the resource is 
actually being used.