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Cannot use Entities in Entity Framework directly with Web-API. RSS

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Last post Apr 25, 2012 12:27 AM by JTBS

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JTBS

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Cannot use Entities in Entity Framework directly with Web-API.

Apr 18, 2012 02:44 AM|LINK

I am not able to use Entities generated by Entity Framework directly in ASP.NET MVC Web-API.

I get error "IsReferenced=true" on class and cannot serialize.

Is there a way to EF in a disconnected way so that entites are generated without "IsReferenced" attribute and can be used directly in Web API for return values as objects.

Ideally don't want to create light weight C# class/entities just to avoid this issue.
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DPeden

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Re: Cannot use Entities in Entity Framework directly with Web-API.

Apr 18, 2012 03:41 PM|LINK

JTBS
Ideally don't want to create light weight C# class/entities just to avoid this issue.

http://en.wikipedia.org/wiki/Single_responsibility_principle
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JTBS

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Re: Cannot use Entities in Entity Framework directly with Web-API.

Apr 18, 2012 03:53 PM|LINK

I am little confused... it is easy to read things out of context and get different meaning...

Can someone with ASP.NET MVC WEB API team point me to how I get EF entities to work with Web API.

Closest solution I see is I create yet another set of light weight entities just for the purpose of API exposure but internally I do the mapping to/from Entity Framework generated entities.

OR is there a option in Entity Framework -to avoid this scenario and use it in disconnected fashion [Which generates entities without "IsReferenced" attribute]?

Any thoughts/pointers are appreciated
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Jay_Harlow

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Re: Cannot use Entities in Entity Framework directly with Web-API.

Apr 18, 2012 04:13 PM|LINK
JTBS

Is there a way to EF in a disconnected way so that entites are generated without "IsReferenced" attribute and can be used directly in Web API for return values as objects.

Ideally don't want to create light weight C# class/entities just to avoid this issue.

For JSON you want to use JSON.NET, which I understand will be included in the RC of the web-api.

For XML I want to say you want to use the Data Contract Serializer.
```
GlobalConfiguration.Configuration.Formatters.XmlFormatter.UseDataContractSerializer = true;
```
I don't have my web-api project handy, so I'm going from memory...

Hope this helps

Jay
- Marked as answer by jtbs on Apr 25, 2012 12:21 AM
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JTBS

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36 Posts
Re: Cannot use Entities in Entity Framework directly with Web-API.

Apr 25, 2012 12:27 AM|LINK
Thanks for the response.

I adde JSON.NET ... to help everyone following are detaisl:

1. Use Nuget to install JSON.NET and add to your web-api project

2. Add JsonNetFormatter from: http://blogs.msdn.com/b/henrikn/archive/2012/02/18/using-json-net-with-asp-net-web-api.aspx

3. Add following code to Application_Start in your Global.asax
```
GlobalConfiguration.Configuration.Formatters.Clear();
 JsonSerializerSettings serializerSettings = new JsonSerializerSettings();
 serializerSettings.Converters.Add(new IsoDateTimeConverter());
 GlobalConfiguration.Configuration.Formatters.Add(new JsonNetFormatter(serializerSettings));
```
I tested twice removing above code -I got expected error + adding it back worked great. Hope that helps.

Below are couple of useful alternatives: [If you don't want to use JSON.NET] But I am seeing enough references that WebAPI RC will have JSON.NET -so why not go that path..

http://www.strathweb.com/2012/03/serializing-entity-framework-objects-to-json-in-asp-net-web-api/
- Marked as answer by jtbs on Apr 25, 2012 12:27 AM