Implementation Of Dependency Injection Support in Existing Applications

• May 12, 2023
• 3 minutes to read

This article describes how to implement dependency injection support in the following applications:

• Standalone Web API applications created before v23.1
• XAF ASP.NET Core Blazor applications that don’t include the Application Builder

Project Converter Tool

Use the Project Converter tool to update your application to the latest XAF version. Note that this technique only works if your application code base does not differ significantly from the application code generated by the Solution Wizard.

Manual Update Of a Standalone Web API Application

Standalone Web API applications use the IObjectSpaceProviderFactory service autogenerated by the XAF Solution Wizard. This service creates two default IObjectSpaceProvider objects: for persistent and non-persistent data. To pass IServiceProvider to IObjectSpaceProvider objects, follow the steps below:

1. In the ObjectSpaceProviderFactory.cs file, add the IServiceProvider parameter to the ObjectSpaceProviderFactory constructor.
2. Pass the IServiceProvider object to the NonPersistentObjectSpaceProvider constructor.

EF Core

using DevExpress.EntityFrameworkCore.Security; 
using DevExpress.ExpressApp; 
using DevExpress.ExpressApp.Core; 
using DevExpress.ExpressApp.DC; 
using DevExpress.ExpressApp.EFCore; 
using DevExpress.ExpressApp.Security;   

public sealed class ObjectSpaceProviderFactory : IObjectSpaceProviderFactory { 
    readonly ISecurityStrategyBase security; 
    readonly ITypesInfo typesInfo; 
    readonly IXafDbContextFactory<AppDbContext> dbFactory; 
    readonly IServiceProvider serviceProvider;   

    public ObjectSpaceProviderFactory(IServiceProvider serviceProvider, ISecurityStrategyBase security, ITypesInfo typesInfo, IXafDbContextFactory<AppDbContext> dbFactory) { 
        this.serviceProvider = serviceProvider; 
        this.security = security; 
        this.typesInfo = typesInfo; 
        this.dbFactory = dbFactory; 
    }   

    IEnumerable<IObjectSpaceProvider> IObjectSpaceProviderFactory.CreateObjectSpaceProviders() { 
        yield return new SecuredEFCoreObjectSpaceProvider<AppDbContext>((ISelectDataSecurityProvider)security, dbFactory, typesInfo); 
        yield return new NonPersistentObjectSpaceProvider(serviceProvider, typesInfo, null); 
    } 
}  

Additionally, in the Startup.cs file, in the ConfigureServices method, call the DbContextOptionsBuilder.UseXafServiceProviderContainer method and pass IServiceProvider as its parameter.

services.AddDbContextFactory<AppDbContext>((serviceProvider, options) => { 
    //... 
    options.UseSecurity(serviceProvider); 
    options.UseXafServiceProviderContainer(serviceProvider); 
}, ServiceLifetime.Scoped); 
services.AddDbContextFactory<AuditingDbContext>((serviceProvider, options) => { 
    //... 
    options.UseLazyLoadingProxies(); 
    options.UseXafServiceProviderContainer(serviceProvider); 
}, ServiceLifetime.Scoped); 

XPO Secured

using DevExpress.ExpressApp; 
using DevExpress.ExpressApp.Core; 
using DevExpress.ExpressApp.DC; 
using DevExpress.ExpressApp.Security; 
using DevExpress.ExpressApp.Security.ClientServer; 
using DevExpress.ExpressApp.Xpo;    

public sealed class ObjectSpaceProviderFactory : IObjectSpaceProviderFactory { 
    readonly ISecurityStrategyBase security; 
    readonly ITypesInfo typesInfo; 
    readonly IXpoDataStoreProvider dataStoreProvider; 
    readonly IServiceProvider serviceProvider;   

    public ObjectSpaceProviderFactory(IServiceProvider serviceProvider, ISecurityStrategyBase security, ITypesInfo typesInfo, IXpoDataStoreProvider dataStoreProvider) { 
        this.serviceProvider = serviceProvider; 
        this.security = security; 
        this.typesInfo = typesInfo; 
        this.dataStoreProvider = dataStoreProvider; 
    } 

    public IEnumerable<IObjectSpaceProvider> CreateObjectSpaceProviders() { 
        return new IObjectSpaceProvider[] { 
                new SecuredObjectSpaceProvider((ISelectDataSecurityProvider)security, dataStoreProvider, true), 
                new NonPersistentObjectSpaceProvider(serviceProvider, typesInfo, null) 
            }; 
    } 
} 

XPO Non-Secured

If your XAF XPO application uses non-secured XPObjectSpaceProvider, pass the IServiceProvider object to the XPObjectSpaceProvider constructor.

using DevExpress.ExpressApp; 
using DevExpress.ExpressApp.Core; 
using DevExpress.ExpressApp.DC; 
using DevExpress.ExpressApp.Xpo;   

public sealed class ObjectSpaceProviderFactory : IObjectSpaceProviderFactory { 
    readonly ITypesInfo typesInfo; 
    readonly IXpoDataStoreProvider dataStoreProvider; 
    readonly IServiceProvider serviceProvider;   

    public ObjectSpaceProviderFactory(ITypesInfo typesInfo, IXpoDataStoreProvider dataStoreProvider, IServiceProvider serviceProvider) { 
        this.typesInfo = typesInfo; 
        this.dataStoreProvider = dataStoreProvider; 
        this.serviceProvider = serviceProvider; 
    } 
    public IEnumerable<IObjectSpaceProvider> CreateObjectSpaceProviders() { 
        yield return new XPObjectSpaceProvider(serviceProvider, dataStoreProvider, true); 
        yield return new NonPersistentObjectSpaceProvider(serviceProvider, typesInfo, null); 
    } 
} 

Manual Update of an ASP.NET Core Blazor Application

To update an XAF ASP.NET Core Blazor application without the Application Builder, go to the YourApplicationName.Blazor.Server\YourApplicationNameBlazorApplication.cs file and override the XafApplication.CreateDefaultObjectSpaceProvider method as shown in the examples below:

EF Core Secured

protected override void CreateDefaultObjectSpaceProvider(CreateCustomObjectSpaceProviderEventArgs args) { 
    IXafDbContextFactory<YourSolutionNameDbContext> dbFactory = 
    ServiceProvider.GetService<IXafDbContextFactory<YourSolutionNameDbContext>>(); 
    SecuredEFCoreObjectSpaceProvider efCoreObjectSpaceProvider = 
    new SecuredEFCoreObjectSpaceProvider((ISelectDataSecurityProvider)Security, dbFactory, TypesInfo); 
    args.ObjectSpaceProviders.Add(efCoreObjectSpaceProvider); 
    args.ObjectSpaceProviders.Add(new NonPersistentObjectSpaceProvider(ServiceProvider, TypesInfo, null)); 
}   

Additionally, in the ConfigureServices method of the YourApplicationName.Blazor.Server\Startup.cs file, call the DbContextOptionsBuilder.UseXafServiceProviderContainer method and pass the IServiceProvider as its parameter.

XPO Secured

protected override void CreateDefaultObjectSpaceProvider(CreateCustomObjectSpaceProviderEventArgs args) { 
    IXpoDataStoreProvider dataStoreProvider = GetDataStoreProvider(args.ConnectionString, args.Connection); 
    args.ObjectSpaceProviders.Add(new SecuredObjectSpaceProvider((ISelectDataSecurityProvider)Security, dataStoreProvider, true)); 
    args.ObjectSpaceProviders.Add(new NonPersistentObjectSpaceProvider(ServiceProvider, TypesInfo, null)); 
} 

XPO Non-Secured

In non-secure XAF XPO applications, navigate to the YourApplicationName.Blazor.Server\BlazorApplication.cs file and pass the IServiceParameter as shown in the example above: XPO: Non-Secured Standalone Web API Application.