How to create customers api using ASP.NET MVC4 and Web API for predefined json result

Question

In ASP.NEt MVC4 application Json Web api needs to be created to serve requests which can expressed using the urls like:

1. http://localhost:52216/erp/api/customers return all customers

2. http://localhost:52216/erp/api/customers?term=soft return list of customers whose same contains "soft". Used for autocomplete.

Result from those requests must be json object which contains single property , customers which contain array of customers found.

3. post request to http://localhost:52216/erp/api/customers should add new customer which is specified in request body as json

Result from this method must be json object which contains single property, customer which contain saved customer with some properties changed.

For this API controller below is tried to use. Typing browser http://localhost:52216/erp/api/customers returns error in xml format

<Error><Message>No HTTP resource was found that matches the request URI 'http://localhost:52216/erp/api/customers'.</Message>
<MessageDetail>No action was found on the controller 'Customers' that matches the request.</MessageDetail>
</Error>

How to fix this ? Which is propery way to crete API class for such request?

Request return data format cannot changed. Class method names can changed and separate methods with different names can created if required.

using Erp.Models;
using System.Web.Http;

namespace Erp.Controllers
{
    [Authorize]
    public class CustomersController : ApiController
    {
        public object Get(string term)
        { 
            Customer[] res = CustomerRepository.GetAllOrForTerm(term);
            return new { customers = res };
        }

        public object Post([FromBody]Customer customer)
        {
            Customer res = CustomerRepository.Save(customer);
            return new { customer = res };
        }
    }
}

default routing is used:

    config.Routes.MapHttpRoute(
        name: "DefaultApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional }
    );

Update

Application is running from erp virtual directory so removing it does not help.

I tried also in browser

http://localhost:52216/erp/api/customers/get

and

http://localhost:52216/erp/api/customers/Get

but got error

<Error>
<Message>
No HTTP resource was found that matches the request URI 'http://localhost:52216/erp/api/customers/get'.
</Message>
<MessageDetail>
No action was found on the controller 'Customers' that matches the request.
</MessageDetail>
</Error>

Answer 1

The following controller should work fine with the default routes configuration:

public class CustomersController : ApiController
{
    // This will match GET /api/customers
    public HttpResponseMessage Get()
    {
        Customer[] res = CustomerRepository.GetAllCustomers();
        return Request.CreateResponse(HttpStatusCode.OK, result);
    }

    // This will match GET /api/customers?term=foo_bar
    public HttpResponseMessage Get(string term)
    {
        Customer[] res = CustomerRepository.GetAllOrForTerm(term);
        return Request.CreateResponse(HttpStatusCode.OK, res);
    }

    // This should match POST /api/customers
    public HttpResponseMessage Post(Customer customer)
    {
        ...
        return Request.CreateResponse(HttpStatusCode.Created, customer);
    }
}

Also in your code you seem to have decorated your CustomersController with the [Authorize] attribute without actually explaining what kind of authorization mechanism you are using. But anyway, if you are using authorization, make sure you provide valid credentials with the request.

And while you are on it, checkout ServiceStack as an alternative to the Web API. You will be mesmerized by how much easier it is to write RESTful web services in .NET. In Web API v2 they did a step closer to ServiceStack by introducing attribute based routing (which simplified routing) but they have yet another step to make which is message based services. Then the Web API will really be useful. Until they make this final step, personally I will continue using ServiceStack which offers such a simplicity to write RESTfule services.