Custom .NET Controller

In this article, we will demonstrate how to extend the M.App Enterprise Server with a custom C#.NET Controller. Additionally, we will show how to protect the controller from external access using API Key Authentication.

Install the NuGet Package Microsoft.AspNet.WebApi.Core for your project.

In order to derive from our .NET controller, the corresponding dependencies must be created in the project. To do this, go to the project in Visual Studio, right-click on “References” and select “Add Reference…”. In the following dialog, select the “Browse” option and add the two dll files, MApp.Code.dll and MApp.Endpoints.dll. You can find these in the bin directory in the installation folder of M.App Enterprise. We recommend copying the dll files to your own project directory first and creating the reference from there.

Create a C# class file and add following sample code, which contains a simple controller and an [HttpGet] action.

using MApp.Endpoints;
using MApp.Core;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using System.Web.Http;
using MApp.Data;
using System.Collections.Generic;
using System.Linq;
using Newtonsoft.Json;

namespace CustomControllers
{
    [MAppAuthentication(AllowedClients.ApiKey)]
    public class CustomController : MAppTenantController
    {
        [HttpGet]
        [Route("api/v1/custom/action1")]
        public async Task<IHttpActionResult> Action1()
        {
            //Fetch and process data
            var responseObject = new
            {
                message = "Hello World!"
            };

            return this.JsonData(JsonConvert.SerializeObject(responseObject));
        }
    }
}

Now you have a custom controller which extends our basic controller MAppTenantController. In this example we also added an ApiKey authentication attribute, which limits the public access to the actions of this controller. So calling this action is only allowed with a valid access token.

Furthermore, it would also be possible to allow access only for requests from M.App Enterprise Apps. To do this, you need to change the authorization attribute to [MAppAuthentication(AllowedClients.App)] only.

The [Route("...")] attribute defines the public url for this action. In our case the http-get will be available at http://{YOUR MAE WEB PATH}/api/v1/custom/action1.

By extending from our basic controller MAppTenantController you get access to various functions and properties provided by M.App Enterprise Server.

For example:

Selecting the Database Connections stored in your M.App Enterprise environment.

List<Connection> connections = (await GetTenant().Database.SelectAsync<Connection>()).ToList();

Executing a SQL query command.

Database database = new Database({ConnectionString}, DbProviderType.PostgreSql);
database.ExecuteNonQuery("UPDATE mytable SET column1 = 'value1'");

Build your Visual Studio solution and copy the compiled .dll files to your M.App Enterprise installation directory and paste the files into the bin folder

After placing the .dll files into the bin folder of M.App Enterprise, your controller actions become available to be called.

As an example, you can call a function to fetch the data in your app:

  //custom script placed in M.App Enterprise AppEngine 
  function fetchData() {
    fetch('../api/v1/custom/action1', { 
      headers: { 
        'Tenant': {TENANT}, 
        'Authorization': `ApiKey {ACCESS TOKEN}` 
      } 
    })
    .then(response => {
        debugger;
        return response.json();
    })
    .then(data => {
        debugger;
        console.log(data);
    });
  }
  
  fetchData();

Congratulations! You have created your first custom controller and extended successfully our base M.App Enterprise controller.