How to format UriTemplate for multiple parameters

Question

I am working on sample application to get employment data from a server using a REST API.

[OperationContract]
[WebGet(UriTemplate = "/employ?id={empIDs}", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json)]
List GetEmpList(string empIDs);

To get the employ details I called it and it worked fine.

GetEmpList("1");

Above code takes only one ID, but I want multiple employ details. Then to get multiple employ I need to use URL <root>/employ?1d=1&id=41&id=45

But to solve this I called the GetEmpList() API as below

GetEmpList("1&id=41&id=45"); 

But it give me an exception:

System.ServiceModel.EndpointNotFoundException

Message :
There was no endpoint listening at https://sample.com/rest/employ?id=221%26id%3d211%26id%3d%26id%3d1057%26id%3d%26id%3d445 that could accept the message. This is often caused by an incorrect address or SOAP action. See InnerException, if present, for more details.

If I hard code URL as

[OperationContract]
[WebGet(UriTemplate = "/employ?id={empIDs}&id={empIDs2}&id={empIDs3}", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json)]
List GetEmpList(string empIDs, string empIDs2, string empIDs3);

then it works, but the problem is number of employ varies based on request.

My question is how to pass multiple parameter to an UriTemplate ?

Answer 1

There is no standard way to pass in an array-type argument in a query string, but you can do so yourself fairly easily. Assuming all your employee IDs are going to be integers, probably the easiest way (from a technical and a human-readable standpoint) is to pass them in as a comma-delimited string.

Example (unchanged from your original code):

[OperationContract]
[WebGet(UriTemplate = "/employ?id={empIDs}", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json)]
List GetEmpList(string empIDs);

Call:

GetEmpList("1,2,13");

In the method implementation, you simply do:

var ids = empIDs.Split(new [] { ',' }).Select(id => Int32.Parse(id));

See also this answer .