WebAPI Fall Update 2012 : ResultLimit support on Queryable

In case you have missed this hidden gem from the update, Queryable now supports following four properties. I will cover other properties in separate blog post.

  • ResultLimit
  • StableOrdering
  • LamdaNestingLimit
  • HandleNullPropogation

Having support for ResultLimit is really great news for people using oData support in WebAPI.

This means that you can now set the upper limit on the amount of records that will be returned for a given resource when you apply Queryable attribute. This is very important step to make sure that the client of your API don’t unnecessarily run large queries therby limiting the system scalability.

If you want this capability on an existing system, ensure that oData version of API is latest. Mine is Microsoft.AspNet.WebApi.OData.0.2.0-alpha-121031\lib\net40\System.Web.Http.OData.dll. I have also applied the fall 2012 update.

Let’s say you this method on /webapi/Accounts

image1

and you perform simple Get operation /webapi.

image2

This returns count of 3.

Now add the ResultLimit property on Queryable  Attribute and set this value to 2.

image3

Let’s execute the same query again.

image4

It returns 2 as expected.

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