This is what I came up with: http://pastie.org/539064

Let me know what you think of it.

-Mark

mappedObject = context.TryGetMappedObject(ctx=>mapper.CreateObject(ctx.DestinationType))

The lambda being a Func that gets called when the context could not resolve the mappedObject. The context can use the lambda’s result to add it to its cache if it so requires (answerable by context).

my 5 cent

TypeMap map = context.TypeMap;

map.BeforeMap(context.SourceValue, mappedObject);
map.AfterMap(context.SourceValue, mappedObject);

return mappedObject;
}

private object GetMappedObject(ResolutionContext context, IMappingEngineRunner mapper)
{
TypeMap map = context.TypeMap;
IConfigurationProvider configurationProvider = mapper.ConfigurationProvider;
var profileConfiguration = configurationProvider.GetProfileConfiguration(map.Profile);

if (map.CustomMapper != null)
{
return map.CustomMapper(context);
}

if (context.DestinationValue == null && context.InstanceCache.ContainsKey(context))
{
return context.InstanceCache[context];
}

if (context.SourceValue != null || !profileConfiguration.MapNullSourceValuesAsNull)
{
object mappedObject = context.DestinationValue ?? mapper.CreateObject(context.DestinationType);

context.InstanceCache.Add(context, mappedObject);

map.GetPropertyMaps().ToList().ForEach(pm => MapPropertyValue(context, mapper, mappedObject, pm));
}

return null;
}

http://pastebin.com/m4cb8f96c
^ if unreadable.

I would try and address this first…

Yes, not posting the tests was a bad idea. I think I’m also running into the issue where all my tests are black-box integration tests. With the design more locked down, I think it’s time to get unit tests in place.

You know, that’s how the code looked at first, multiple exit points. Flattening seems to be key here….

Yeah, there’s some of that going around. I don’t that will fix the levels of nested IFs, however.

@Neil

I do like that, I think it brings me one step closer to Chain of Responsibility.

I would solve it with a by implementing a Chain of Responsibility pattern. Worked out very well for me when I had a very similar issue a few weeks ago.

The bottom line, does it work? Do you have unit tests w/ coverage?

Nested if statements like the above is a classic case where it falls in the “bah” or “mmm”… let’s tackle things that are more pressing.

Also, it’s not that “very, very long” like you say, it fits on one page, and there’s only two “top level if”. Maybe adding comments would suffice for now.

no change: Don’t add code and/or complexity if the current solution works.

change: On the other hand, if you find the need to add comments then, yeah, time to refactor!

mappedObject = tryMethod1(..)

if (mappedObject != null)
mappedObject = tryMethod2(..)

if (mappedObject != null)
mappedObject = tryMethod3(..)

return mappedObject;