September 2014

I am currently learning how to implement a RESTful API and am using RESTful API Tutorial as a resource. I quickly needed to add functionality to my existing ASP.NET MVC site that I am building hence the need to document my steps for others who might have a need in doing this also.

I am working in Visual Studio 2013 and ASP.NET MVC 5.

Add a New Controller

This is fairly easy to do. Right click on the Controllers folder. Select “Add > Controller”. The “Add Scaffold” dialog will appear.

At this point, you can choose the Web API you would like to add. I chose “Web API 2 Controller with read/write actions” to get some samples to start working with.

Visual Studio will then add the new controller, references to System.Web.Http and System.Web.Routing and open a new readme.txt document with additional instructions. I will be documenting these instructions below.

Add Using Statements

At the beginning of the Global.asax.cs file, add the following:

using System.Web.Http;
using System.Web.Routing;

Add Application_Start in the Global.asax

If you don’t already have it, add Application_Start() to your Global.asax.cs file.

protected void Application_Start()
{

}

Add GlobalConfiguration.Configure(WebApiConfig.Register) to the beginning of Application_Start(). Here is what mine looks like now:

protected void Application_Start()
{
     GlobalConfiguration.Configure(WebApiConfig.Register);
     AreaRegistration.RegisterAllAreas();
     FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
     RouteConfig.RegisterRoutes(RouteTable.Routes);
     BundleConfig.RegisterBundles(BundleTable.Bundles);
     BundleMobileConfig.RegisterBundles(BundleTable.Bundles);
}

And that is all you need to do. You can use RESTful Api Tutorial to learn more about RESTful API’s.

I recently needed to find a solution where I could run/schedule jobs within an ASP.NET website. The site is hosted where we do not have access to the server and cannot use Windows Services. Historically, it has been a problem running scheduled jobs within a web environment up until now. A hot new project called Hangfire has come up with a solution and is built with Katana, Microsofts’s OWIN implementation.

In this tutorial, I will cover the steps needed to run Hangfire within a project that does not use the ASP.NET MVC framework. I am using the Quick Start steps from Hangfire as a reference point.

Installing Hangfire
Add an OWIN Startup Class
Configure Hangfire
Add a job or recurring task
Using the Dashboard

Installing Hangfire

Use Nuget and install Hangfire (comes with SQL Server Storage) in your project. You could also use the Package Manager Console.

PM> Install-Package Hangfire

Add an OWIN Startup Class

Create a Startup.cs file in the root of your website and add the following:

using Hangfire;
using Hangfire.SqlServer;
using Microsoft.Owin;
using Owin;

[assembly: OwinStartup(typeof(YourNamespace.Startup))]
namespace YourNamespace
{
    public partial class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            Hangfire.ConfigureHangfire(app);
            Hangfire.InitializeJobs();            
        }
    }
}

Notice the [assembly: OwinStartup(typeof(YourNamespace.Startup))] line. This hooks up YourNamespace.Startup to OWIN and the IIS integrated pipeline.

Configure Hangfire

Create another file called Hangfire.cs. It’s not required but I did it to centralize my custom Hangfire code. Here is a sample of what I put in this file:

using Hangfire;
using Hangfire.SqlServer;
using Hangfire.Dashboard;
using Microsoft.Owin;
using Owin;

namespace YourNamespace
{
    public class Hangfire
    {
        public static void ConfigureHangfire(IAppBuilder app)
        {
            app.UseHangfire(config =>
            {
                config.UseSqlServerStorage("HangFireDB");
                config.UseServer();
                config.UseAuthorizationFilters(); //allow all users to access the dashboard
            });
        }

        public static void InitializeJobs()
        {
            RecurringJob.AddOrUpdate<AccountStatusJob>(j => j.Execute(), "0 1,21 * * *");
        }
    }
}

The Job or Recurring Task

In the example above, I created a method called InitializeJobs(). This is where you create the job/task(s) using CRON expressions. Keep in mind that Hangfire uses UTC for its time scheduling so base your times accordingly.

I created another class called AccountStatusJob with a static method called Execute() which is what the job will call when it runs. This particular job has a CRON expression setting it to run everyday at 2pm and 6pm Pacific time (converted to UTC). Here is a nice expression builder from ABunchOfUtils.com to help you along.

Using the Dashboard

The Dashboard is really handy! This is where you can see the jobs you have configured, when they ran, when they will run again and you can trigger or delete them! In order to use the Dashboard, you need to navigate to it like so:

http://<yoursite>/Hangfire

The Dashboard is setup to run when you are accessing it locally (such as localhost) but when it is in production it requires authorization. You need to use Nuget or the Package Manager Console and install Hangfire Dashboard Authorization Filters.

PM>Install-Package Hangfire.Dashboard.Authorization

What I did to get around this security and not have to implement any ASP.NET Identity was add the following line in the example above:

config.UseAuthorizationFilters();

Read more about the Dashboard authorization.

The days of web forms are quickly passing and ASP.NET MVC is running strong. What a great time to find solutions to run the new with the old.

Archives for September 2014

How To: Add WebAPI to an Existing ASP.NET MVC Project