How to call web api multiple GET methods through AJAX

Question

I have added two GET methods into webapi as follow:

    public IList<ProductDTO> GetAllProducts()
    {
        ProductManager pm = new ProductManager();

        return pm.RetrieveAllProducts();
        //return pm.RetrieveAllProducts();
    }

    public ProductDTO GetProduct(int i)
    {
        ProductManager pm = new ProductManager();

        return pm.RetrieveAllProducts().Where(c => c.Id == i).FirstOrDefault();
        //return pm.RetrieveAllProducts();
    }

Problem, when i only kept one get method GetAllProducts() then it works fine. but when i added GetProduct(int i) then giving me error as Not found 404 error.

Please guide me how i could keep both the mthod and allow to access method having argument.

calling as follow:

           $.ajax({
            type: 'GET',
            url: 'api/values/GetProduct/1',   //giving error as NOT FOUND
            contentType: 'json',
            dataType: 'json',
            success: function (data) {
                $.each(data, function (key, value) {
                    //stringify
                    alert(key);
                    alert(value);
                    var jsonData = JSON.stringify(value);

                    //Parse JSON
                    var objData = $.parseJSON(jsonData);
                    var id = objData.Id;
                    var Cost = objData.Cost;
                    var ProductName = objData.ProductName;
                    var Description = objData.Description;
                    $('<tr><td>' + id + '</td><td>' + ProductName +
                    '</td><td>' + Cost + '</td></tr>').appendTo('#ProductDivWebApi');
                });
            },
            error: function (xhr) {
                alert(xhr.responseText);
            }
        });

i have added this WEBAPI into MVC 4 project.

its route shows as below:

   public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "ProductManagement", action = "Index", id = UrlParameter.Optional }
        );
      }

Please guide

Answer 1

The routes on the ASP.NET WEB API is different than ASP.NET MVC. You have the GET methods, so, just call the controller using the GET verb and the framework will solve it for you. I recommend you rename the methods to a verb, Get, Post, Put, Delete, etc.

In your case, call the method by /api/{controller}/{id}. In this case, data is a single object (because you have returned only a ProductDTO), so do not loop in it.

You have specified json, so jquery will be deserialized it in a object for you. For sample:

$.ajax({
    type: 'GET',
    url: 'api/values/1', 
    contentType: 'json',
    dataType: 'json',
    success: function (data) {
        // data is a single object, do not loop in it.
        // you have specified json, so, it will be deserialized     

        var id = data.Id;
        var Cost = data.Cost;
        var ProductName = data.ProductName;
        var Description = data.Description;

        $('<tr><td>' + id + '</td><td>' + ProductName +
        '</td><td>' + Cost + '</td></tr>').appendTo('#ProductDivWebApi');
        });
    },
    error: function (xhr) {
        alert(xhr.responseText);
    }
});

I also recommend you to do some things like this on Web API:

[HttpGet]
public HttpResponseMessage GetProduct(int id)
{
   ProductManager pm = new ProductManager();

   var result = pm.RetrieveAllProducts().Where(c => c.Id == id).FirstOrDefault();

   return Request.CreateResponse(HttpStatusCode.OK, result);
}

On the WebApiConfig.cs file I recommend you configure the routes like this:

public static void Register(HttpConfiguration config)
{
    config.Routes.MapHttpRoute("DefaultApiGet",
                                "api/{controller}",
                                new {action = "Get"},
                                new {httpMethod = new HttpMethodConstraint(HttpMethod.Get)});

    config.Routes.MapHttpRoute("DefaultApiGetWithId",
                                "api/{controller}/{id}",
                                new {id = RouteParameter.Optional, action = "Get"},
                                new {id = @"\d+"});

    config.Routes.MapHttpRoute("DefaultApiWithAction",
                                "api/{controller}/{action}");

    config.Routes.MapHttpRoute("DefaultApiWithActionAndId",
                                "api/{controller}/{action}/{id}",
                                new {id = RouteParameter.Optional},
                                new {id = @"\d+(_\d+)?"});
}