REST Service in ASP.NET Web API

We select the empty template for the creation of the MVC4 application.

In the Global.asax.cs. there are two routes defined; the first is MVC controller and the second is API controller, as in the following.

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

    routes.MapHttpRoute(
        name: "default_Api",
        routeTemplate: "api/{controller}/{t_id}",
        defaults: new { id = RouteParameter.Optional }
    );

    routes.MapRoute(
        name: "default_app",
        url: "{controller}/{action}/{t_id}",
        defaults: new { controller = "home", action = "Index", t_id = UrlParameter.Optional }
    );
}

Now we create a service that removes the data and correspondingly modifies the other data, as in the following.

public static void RegisterRoutes(RouteCollection routes)
{
    routes.MapHttpRoute(
        name: "Default_app",
        routeTemplate: "{controller}/{t_id}",
        defaults: new { t_id = RouteParameter.Optional }
    );
}

Now we create a resource task1, as in the following.

public class Task1
{
    public int T_Id { get; set; }
    public string T_Description { get; set; }
    public int T_Priority { get; set; }
    public DateTime Created { get; set; }
}

We create the controller that exposes various methods that perform the resource, as in the following.

public class Task_Control : ApiController
{
    public IEnumerable<string> Get()
    {
        return new string[] { "val1", "val" };
    }

    public string Get(int t_id)
    {
        return "val";
    }

    public void Post(string val)
    {
    }

    public void Put(int t_id, string val)
    {
    }
}

In this code, we can see that the class Task_Control is derived from ApiController. It has a method for Getting all the tasks, Getting a single task, creating a new task, and editing the task.

now we describe the return type of method.

public class Task_Control : ApiController
{
    public IEnumerable<Task> Get()
    {
        throw new NotImplementedException();
    }

    public Task Get(int t_id)
    {
        throw new NotImplementedException();
    }

    public HttpResponseMessage<Task> Post(Task t_task)
    {
        throw new NotImplementedException();
    }

    public Task Put(Task task)
    {
        throw new NotImplementedException();
    }
}

When we implement the task, first we need to store our task.

public interface ITaskRepository
{
    IEnumerable<Task> Get();
    Task Get(int taskId);
    Task Post(Task task);
    Task Put(Task task);
}

public class TaskRepository : ITaskRepository
{
    private List<Task> Tasks
    {
        get
        {
            if (HttpContext.Current.Cache["Tasks"] == null)
                HttpContext.Current.Cache["Tasks"] = new List<Task>();
            return HttpContext.Current.Cache["Tasks"] as List<Task>;
        }
        set
        {
            HttpContext.Current.Cache["Tasks"] = value;
        }
    }

    public IEnumerable<Task> Get()
    {
        return Tasks;
    }

    public Task Get(int taskId)
    {
        return Tasks.Find(p => p.TaskId == taskId);
    }

    public Task Post(Task task)
    {
        task.TaskId = Tasks.Max(t => t.TaskId) + 1;
        Tasks.Add(task);
        return task;
    }

    public Task Put(Task updatedTask)
    {
        var existingTask = Get(updatedTask.TaskId);
        if (existingTask == null)
            throw new Exception("The Task does not exist.");
        existingTask.Description = updatedTask.Description;
        existingTask.Priority = updatedTask.Priority;
        return existingTask;
    }
}

In this code, Task_Repos is a class that is derived from the ITask_Repos interface. In it, we use the HttpContext.Current.A cache that stores the task.

private readonly ITask_Repos _task_Repos;

public Tasks_Contrl(ITask_Repos task_Repos)
{
    _task_Repos = task_Repos;
}

GET() Method

This method returns all the tasks.

public IEnumerable<Task> Get()
{
    return _task_Repos.Get();
}

GET(T_id) Method

This method is used for a single variable.

public Task Get(int t_id)
{
    var t_task = _task_Repos.Get(t_id);
    if (t_task == null)
    {
        throw new HttpResponseException(new HttpResponseMessage
        {
            StatusCode = HttpStatusCode.NotFound,
            Content = new StringContent("This task is not available")
        });
    }

    return t_task;
}

Post(Task Task) Method

This method adds a resource.

public async Task<HttpResponseMessage> Post(Task task)
{
    var createdTask = _task_Repos.Post(task);

    var response = new HttpResponseMessage(HttpStatusCode.Created)
    {
        Content = new ObjectContent<Task>(createdTask, new JsonMediaTypeFormatter())
    };

    string uri = Url.Route(null, new { id = createdTask.t_Id });
    response.Headers.Location = new Uri(Request.RequestUri, uri);

    return response;
}