Avoiding repeated type definition for each result when projecting in Breeze.js

Question

I'm currently querying an Entity using projections to avoid returning the entire object. It works flawlessly, however, when looking at the actual response from the server, I'm seeing the same type definition repeated for every single element.

For example:

["$type":"_IB_4NdB_p8LiaC3WlWHHQ_pZzrAC_plF4[[System.Int32, mscorlib],[System.String, mscorlib],[System.String, mscorlib],[System.String, mscorlib],[System.Nullable`1[[System.Int32, mscorlib]], mscorlib],[System.Int32, mscorlib],[System.Single, mscorlib]], _IB_4NdB_p8LiaC3WlWHHQ_pZzrAC_plF4_IdeaBlade"

Now, given that every item in the result is sharing the same projection for that query, is there a way to have Breeze only define the Type Description ONCE instead of for every element?

It may not seem like a big deal but as result size increases those bytes do start to add up. At the moment There is little difference between returning the projected values and the entire entity itself due to this overhead.

NOTE: As it turns out, since we use Dynamic Compression of JSON in our real environments, this actually turns out to be a minor issue, since 200KB responses actually turn into less than 20KB traffic after gzip compression. Will probably be closing this question, unless someone has something to add that could be of use to others.

Update 18 September 2014

I decided to "cure" the problem of the long ugly $type names in serialized data for both dynamic types from projection queries and anonymous types created for an endpoint such as "Lookups".

There's a new Breeze Labs nuget package, "Breeze.DynamicTypeRenaming" (search for "Breeze Dynamic Type Renaming"). This adds two files to your Web API project's "Controllers" folder. One is a CustomBreezeConfig which replaces Breeze's default config and resets the Json.Net "Binder" setting with the new DynamicTypeRenamingSerializationBinder; this binder does the type name magic.

Just install the nuget package in your Web API project and it should "just work". In your case, the $type value would become "_IB_4NdB_p8LiaC3WlWHHQ_pZzrAC_plF4, Dynamic".

See an example of it in the "DocCode" sample.

As always, this is a Breeze Lab product, not part of the core Breeze product. It is offered "as is" with no promise of support. I'm pretty sure it's good and has no adverse side-effects. No guarantees. I'm sure you'll let me know if there's a problem.

Answer 1

That IS atrocious, isn't it! That's the C# generated anonymous type. You can get rid of it by casting into a custom DTO type.

I don't know if it is actually harmful. I hate looking at it in any case.

Lately I've been thinking about adding a JSON.NET IContractResolver that detects such uglies and turns them into shorter uglies. Wouldn't be hard. Just haven't had the time.

Why not write that yourself and contribute to the community? We'd be grateful! :-)

Answer 2

Using Dynamic Compression of JSON output has turned this into a non-issue, at least for now, since all that repeated content is heavily compressed server-side.