Where should I put my CreateMap calls for AutoMapper?

Question

I'm creating WCF services that return data contract types by mapping Entity Framework types. What is the best place to put the Mapper.CreateMap calls? Should I do it in each service and only for that service, or should I do it on service startup?

Thoughts?

Answer 1

I think you can create it once and cache in static field:

private static MapClass _MapInstance;

public static MapClass Map
{
    get
    {
        if(_MapInstance == null)
           _MapInstance = Mapper.CreateMap();
        return _MapInstance;
    }
}

Also as far as I know creating mapper is performance-expencive operation, because it may use code generation, sou you shouldn't do it on each call.