Building OData Services With ASP.NET Web API-Part1

Open Visual Studio 2012 >> File >> New >> Project >> Select ASP.NET MVC4 Web Application Template >> Select Web API Template
1
2
It will add automatically OData dependencies for us.Also you can install OData dependencies by using Nuget as well.
3

Create a new controller named CustomersController by rightclicking the Controller folder.
9

 

 

 

 

Then add new class named Customer in the Model folder and add some properties like below
4
Also add one more folder named Domain and add a class named CustomerDataContext, It contains a method Customers which return some customers informations.
5

For setting the OData first i need to do is set up my routing that can be get in to the Customers controller based on OData routing scheme not traditional web api routing schemes.Go to the WebApiConfig class in the App_Start folder and add a helper method GetImplicitEdm for defining entity data model.
6
This method will return IEdmModel which is a interface abstraction on the top of entity data models.ODataModelBuilder class will create set most of the entity data models automatically for you.The main thing you tell to the builder is entity sets are involved and then call the GetEdmModel method associated with the builder class,this will find all the properties on the object,find the types of those properties,look for navigation properties relates other objects in the model. Also add one more route (marked as yellow above) other than the web api route by calling the extension method MapODataRoute which accepts the parameters such as name of the route,a route prefix similar to the api route prefix in the default web api route and then call our helper method GetImplicitEdm.
Then the next step is go to the customers controller and change our base class ApiController to EntitySetController which is generic type takes two arguments,first one is the type of the entity controller represents and second one is the type of key property in that customer object and override Get method of type IQueryble and return our Customers.
8

Run the application and browse the url like below.It will return all the customers.

10

Then i am going to take individual customers. To do that there is a separate override base class called GetEntityByKey and querying by using linq.Note that this is a protected method it expose the service operation is actually a different public method on our base class and the public method will call this one.
11

Go and run the application and browse the url like below.It will return the customer with name “Jameel”

12

Enjoy reading…

Difference between WCF Data Services & ASP.NET WebApi OData

WCF Data Services

  • For this you don’t actually need WCF Knowledge.Coding WCF data services looks like coding normal WCF services. You no need to create service contract and implement those service contracts and configuration also.You just derive from a dataservice class in often running very quickly.
  • WCF Data Services is the most complete implementation of the latest OData specification  from Microsoft.
  • Great for exposing whole data stores with little intervening logic.So you really want to expose a pipeline to the web or to a network for people to come in and query your data store and possibly perform update against it.
  • Complicated to use with non-LINQ provider data
  • Not very extensible

ASP.NET Web API OData

  • New Addition to Web API stack
  • Gives you more control over underlying data sources,model definition and routing conventions.
  • Easier programming model for intervening business logic
  • Can support multiple models per site,mix non-OData with OData services
  • Very extensible

Enjoy reading..