problem of using data from different repositories

Problem

Sometimes there is a need to use the same application objects that must be stored in different storage types. For example, statistical data that can accumulate in significant quantities, in this case, there is no need in complex samples and their frequent changes. The solution of such problems can be the use for such data NoSQL repositories, e.g. MongoDB.

Solutions

more ODataService’s

By default, the service definition data ODataService is performed using the mechanism of dependency injection Unity Container. To change the logic definition of the service data by replacing the service that implements the interface IHttpControllerActivator, as shown in the example below:

namespace IIS.MyProject
{
    using System;

    internal static class ODataConfig
    {
        public static void Configure(HttpConfiguration config, IUnityContainer container)
        {
            // Use Unity as the WebAPI dependency resolver 
            config.DependencyResolver = new UnityDependencyResolver(container);

            // Map an OData Service with basic objects 
            config.MapODataServiceDataObjectRoute(new DefaultDataObjectEdmModelBuilder(new[]
            {
                Assembly.Load("MyProject.Objects"),
            }));

            // Map an OData Service with service objects 
            config.MapODataServiceDataObjectRoute(new DefaultDataObjectEdmModelBuilder(new[]
            {
                typeof(ApplicationLog).Assembly,
                typeof(UserSetting).Assembly,
                typeof(FlexberryUserSetting).Assembly,
                typeof(Lock).Assembly
            }), "service", "service");

            // Replace IHttpControllerActivator service 
            config.Services.Replace(typeof(IHttpControllerActivator), new ControllerActivator(container));
        }
    }
}

Important: Replacement service should vypolnyaetsya after a method invocation MapODataServiceDataObjectRoute, otherwise it will be replaced once again by the realization NewPlatform.Flexberry.ORM.The ODataService.DataObjectControllerActivator

The service that implements the interface IHttpControllerActivator may be similar to the following:

namespace IIS.MyProject
{
    using System;

    public class ControllerActivator : IHttpControllerActivator
    {
        private readonly IUnityContainer _container;
        private readonly IHttpControllerActivator _defaultActivator;

        public ControllerActivator(IUnityContainer container)
        {
            _container = container;
            _defaultActivator = new DefaultHttpControllerActivator();
        }

        public IHttpController Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
        {
            if (controllerDescriptor.ControllerName == "DataObject")
            {
                ManagementToken token = request.GetODataServiceToken();

                string dataServiceName = null;
                if (token.Route.RoutePrefix == "odata")
                    dataServiceName = "MSSQLDataService";
                else if (token.Route.RoutePrefix == "service")
                    dataServiceName = "MongoDbDataService";

                return new DataObjectController(_container.Resolve<IDataService>(dataServiceName), token.Model, token.Events, token.Functions);
            }

            return _defaultActivator.Create(request, controllerDescriptor, controllerType);
        }
    }
}

In this case, when referring to ODataService was on the route service will be used named check IDataService with the name MongoDbDataService, when referring to ODataService was on the route odata will be used named check IDataService with the name MSSQLDataService.

An example configuration for this service:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <!-- ... -->
  <unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
    <container>
      <register name="MongoDbDataService" type="ICSSoft.STORMNET.Business.IDataService, ICSSoft.STORMNET.Business" mapTo="NewPlatform.Flexberry.ORM.MongoDbDataService, NewPlatform.Flexberry.ORM.MongoDbDataService">
        <constructor />
        <property name="CustomizationString" value="SERVER=server;Trusted_connection=yes;DATABASE=database;" />
      </register>
      <register name="MSSQLDataService" type="ICSSoft.STORMNET.Business.IDataService, ICSSoft.STORMNET.Business" mapTo="ICSSoft.STORMNET.Business.MSSQLDataService, ICSSoft.STORMNET.Business.MSSQLDataService">
        <constructor />
        <property name="CustomizationString" value="SERVER=server;Trusted_connection=yes;DATABASE=database;" />
      </register>
      <!-- ... -->
    </container>
  </unity>
</configuration>

Note: When you use this solution, ember application will need tuning adapters](efd2_adapters.html).

the definition of the type of the service data object type

Also define the type of data service is possible, based on the type of data objects to which there is an appeal, in this case, you can register one ODataService, as in the example below:

namespace IIS.MyProject
{
    using System;

    internal static class ODataConfig
    {
        public static void Configure(HttpConfiguration config, IUnityContainer container)
        {
            // Use Unity as the WebAPI dependency resolver 
            config.DependencyResolver = new UnityDependencyResolver(container);

            // Map The OData Service 
            config.MapODataServiceDataObjectRoute(new DefaultDataObjectEdmModelBuilder(new[]
            {
                Assembly.Load("MyProject.Objects"),
                typeof(ApplicationLog).Assembly,
                typeof(UserSetting).Assembly,
                typeof(FlexberryUserSetting).Assembly,
                typeof(Lock).Assembly
            }));

            // Replace IHttpControllerActivator service 
            config.Services.Replace(typeof(IHttpControllerActivator), new ControllerActivator(container));
        }
    }
}

Now the service that implements the interface IHttpControllerActivator may be similar to the following:

namespace IIS.MyProject
{
    using System;

    public class ControllerActivator : IHttpControllerActivator
    {
        private readonly IUnityContainer _container;
        private readonly IHttpControllerActivator _defaultActivator;

        public ControllerActivator(IUnityContainer container)
        {
            _container = container;
            _defaultActivator = new DefaultHttpControllerActivator();
        }

        public IHttpController Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
        {
            if (controllerDescriptor.ControllerName == "DataObject")
            {
                string dataServiceName = null;
                switch (request.GetRouteData().Values["odataPath"])
                {
                    case "ODataPathToMyObject":
                    case "ODataPathToMyOtherObject":
                        dataServiceName = "MSSQLDataService";
                        break;
                    default:
                        dataServiceName = "MongoDbDataService";
                        break;
                }

                ManagementToken token = request.GetODataServiceToken();
                return new DataObjectController(_container.Resolve<IDataService>(dataServiceName), token.Model, token.Events, token.Functions);
            }

            return _defaultActivator.Create(request, controllerDescriptor, controllerType);
        }
    }
}

Source code for this example can be found in the repository FlexberryOrmMongoDbDataServiceDemo.ODataBackend.