What does PathTemplate.StartsWith("~/entityset") exactly do in Odata Web API Routing

Question

I can't figure out what this code does.

public override string SelectController(ODataPath odataPath, HttpRequestMessage request)
{
    return odataPath != null &&
           odataPath.PathTemplate.StartsWith("~/entityset", 
                                  StringComparison.OrdinalIgnoreCase) ? "A" : null;
}

I know the syntactic meaning, but what does StartsWith("~/entityset" do ?

The problem is ~/entityset. I have no reference of what this entity set is and where is it taken from. I guess it could represent some entity set , which one ?

Is it some default OData mechanish to check URLs?

I would look at OdataPath.PathTemplate configuration on your middleware. Also can be that someone changed the "~/entityset" to be "A". — Bart Calixto, Jun 23 '15 at 10:19
@Bart Middleware ? I am using EF to create model and then the standard SelectController and SelectAction functions in my routing. — Novak007, Jun 23 '15 at 10:20
Possibly relevant: http://stackoverflow.com/questions/3077558/use-of-tilde-in-asp-net-path — fk2, Jun 23 '15 at 10:20
btw, this *may* help: http://www.asp.net/web-api/overview/odata-support-in-aspnet-web-api/odata-routing-conventions — Bart Calixto, Jun 23 '15 at 10:25

score 1 · Answer 1 · answered Jul 03 '15 at 15:55

This is used to decide on the routing within OData. Here some example URLs and what their path templates would be that all start with ~/entityset

http://localhost/odata/Students

"~/entityset"

http://localhost/odata/Students(1)

"~/entityset/key"

http://localhost/odata/Students(1)/Teachers

"~/entityset/key/navigation"

To find out which entity set it is you can look at the segments making up the path

((EntitySetPathSegment)request.ODataProperties().Segments.First()).EntitySetName

Segments.First() won't necessarily be a EntitySetPathSegment unless the path starts with ~/entityset so make sure you make that check first.

What does PathTemplate.StartsWith("~/entityset") exactly do in Odata Web API Routing

1 Answers1