What is the best way to retrieve data using Web API 2 and AngularJS - angularjs

Question

I am just learning on how to use Web API with angular but I am having a few issues on retrieving data and I would appreciate it if someone could help me.
I have a controller called GetUserController with the following methods.
public class GetUserController : ApiController
{
[HttpGet]
public string GetUserName()
{
var user = "John Doe"
return user;
}
[HttpGet]
public string GetUserName2()
{
string user = "Jane Doe";
return user;
}
}
//Angular side of things
function getUser() {
return $http.get('/api/GetUser').then(function (data) {
return data;
});
}
The above code works fine and and returns the first user from the controller . however when I try to get the second by using the below angular code:
function getUser() {
return $http.get('/api/GetUser/GetUserName2').then(function (data) {
return data;
});
}
This does not work for some reason it says it can't find the GetUserName2 method. Am I missing something ? Please help?
EDIT: The error i'm getting is : Multiple actions were found that match the request

Answer 1

As #shammelburg has pointed out, this is as a result of Web.API not being able to match your request to a controller/method.
It's not so much that it's not RESTful, and has nothing to do with the verb you are using... it's just that an appropriate route map was not found.
Per the accepted answer, you can add another generic route map to enable the method of access you are attempting, however a more specific option exists using attribute routing:-
public class GetUserController : ApiController
{
[Route("api/getuser")]
[HttpGet]
public string GetUserName()
{
var user = "John Doe"
return user;
}
[Route("api/getuser/getusername2")]
[HttpGet]
public string GetUserName2()
{
string user = "Jane Doe";
return user;
}
}
And to enable the use of attribute routes, add this to your WebApiConfig class:-
config.MapHttpAttributeRoutes();
This method allows you to setup specific custom mappings of URLs to controllers/methods at the individual method level, without having to make a global route map that may conflict with something else in your application at a later date.
You can find more info on attribute routing here
Whilst the above will resolve the specific issue you are having, there would in practice be a different way to implement the example you gave:-
public class GetUserController : ApiController
{
[Route("api/user/{id}")]
[HttpGet]
public string GetUserName(int id)
{
// this would be replaced with some sort of data lookup...
var user = "unknown";
if (id == 1) {
user = "John Doe";
} else if (id == 2) {
user = "Jane Doe";
} // and so on...
return user;
}
}
In the above, the URL api/user/x where x is a number, e.g. api/user/1 will match the GetUserName method of the GetUserController and pass the number as an argument to the method.
This would be accessed using something like this in Angular:-
function getUser(id) {
return $http.get('/api/user/' + id).then(function (data) {
return data;
});
}

Answer 2

This is caused because it is not a true RESTful call which use HTTP verbs, GET, POST, PUT, DELETE.
The way to get your code to work is by altering your WebApiConfig.cs file.
From:
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
To:
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
As you can see we've added the {action} to the routeTemplate which makes this very much like a MVC Controller.
This allows you to call your API methods (GetUserName & GetUserName2) name like you are trying to do in your angular $http function.
Example:
return $http.get('/api/GetUser/GetUserName')
return $http.get('/api/GetUser/GetUserName2')