Add ability for model types to be placed on input fields [WIP] feedback wanted

[colanconnon]

Add the ability to have a model type on the input class in mutations for more code reuse. This is my first time contributing so some feedback is welcome! I am borrowing some ideas from #121

[coveralls]

Coverage decreased (-0.3%) to 93.476% when pulling 854e872 on colanconnon:master into 1e34dfb on graphql-python:master.

[coveralls]

Coverage increased (+0.1%) to 93.898% when pulling a719580 on colanconnon:master into 1e34dfb on graphql-python:master.

[coveralls]

Coverage increased (+0.1%) to 93.898% when pulling 3da4b2b on colanconnon:master into 1e34dfb on graphql-python:master.

[picturedots]

Thanks for this -- tried and it and I get errors when the reducer runs
unhashable type: 'String' --
/usr/local/lib/python3.5/site-packages/graphql/type/typemap.py in reducer

59.     if type.name in map: 
    

But it also might be an instance of this error: #139 or related to the fact the graphene reducer doesn't recognize the type DjanngoModelInput when running is_graphene_type() .

[spockNinja]

Thanks for the idea. An easy way to generate Input based on models is definitely useful.

I'll point out a few similar alternatives.

1. There is already support for mutations that utilize existing DRF Serializers. Docs here
2. There is another PR in the works to do the same with native Django Forms.

Both of those options allow for validation and such to be handled by the serializer/form. They also have a default mutate that does what you would expect, validating and saving the serializer/form. So I think those two approaches should cover this functionality.

Are there any advantages of this approach over those two solutions that I am not thinking of?

[firaskafri]

@colanconnon still interested to work on this?

[phalt]

I'd like to tidy up some of the PRs, so if we still want to work on this let me know or I will close this in 1 week.