Added ability to set/create service provider without initializing the ABP application.

framework/src/Volo.Abp.Core/Volo/Abp/AbpApplicationWithExternalServiceProvider.cs

@@ -18,7 +18,24 @@ namespace Volo.Abp
             services.AddSingleton<IAbpApplicationWithExternalServiceProvider>(this);
         }
 
-        public void Initialize(IServiceProvider serviceProvider)
+        void IAbpApplicationWithExternalServiceProvider.SetServiceProvider([NotNull] IServiceProvider serviceProvider)
+        {
+            Check.NotNull(serviceProvider, nameof(serviceProvider));
+            
+            if (ServiceProvider != null)
+            {
+                if (ServiceProvider != serviceProvider)
+                {
+                    throw new AbpException("Service provider was already set before to another service provider instance.");
+                }
+                
+                return;
+            }
+            
+            SetServiceProvider(serviceProvider);
+        }
+
+        public void Initialize([NotNull] IServiceProvider serviceProvider)
         {
             Check.NotNull(serviceProvider, nameof(serviceProvider));
 

framework/src/Volo.Abp.Core/Volo/Abp/AbpApplicationWithInternalServiceProvider.cs

@@ -31,11 +31,22 @@ namespace Volo.Abp
             Services.AddSingleton<IAbpApplicationWithInternalServiceProvider>(this);
         }
 
-        public void Initialize()
+        public IServiceProvider CreateServiceProvider()
         {
+            if (ServiceProvider != null)
+            {
+                return ServiceProvider;
+            }
+            
             ServiceScope = Services.BuildServiceProviderFromFactory().CreateScope();
             SetServiceProvider(ServiceScope.ServiceProvider);
             
+            return ServiceProvider;
+        }
+
+        public void Initialize()
+        {
+            CreateServiceProvider();
             InitializeModules();
         }
 

framework/src/Volo.Abp.Core/Volo/Abp/IAbpApplicationWithExternalServiceProvider.cs

@@ -5,6 +5,16 @@ namespace Volo.Abp
 {
     public interface IAbpApplicationWithExternalServiceProvider : IAbpApplication
     {
+        /// <summary>
+        /// Sets the service provider, but not initializes the modules.
+        /// </summary>
+        void SetServiceProvider([NotNull] IServiceProvider serviceProvider);
+        
+        /// <summary>
+        /// Sets the service provider and initializes all the modules.
+        /// If <see cref="SetServiceProvider"/> was called before, the same
+        /// <see cref="serviceProvider"/> instance should be passed to this method.
+        /// </summary>
         void Initialize([NotNull] IServiceProvider serviceProvider);
     }
 }

framework/src/Volo.Abp.Core/Volo/Abp/IAbpApplicationWithInternalServiceProvider.cs

@@ -1,7 +1,20 @@
-namespace Volo.Abp
+using System;
+
+namespace Volo.Abp
 {
     public interface IAbpApplicationWithInternalServiceProvider : IAbpApplication
     {
+        /// <summary>
+        /// Creates the service provider, but not initializes the modules.
+        /// Multiple calls returns the same service provider without creating again.
+        /// </summary>
+        IServiceProvider CreateServiceProvider();
+
+        /// <summary>
+        /// Creates the service provider and initializes all the modules.
+        /// If <see cref="CreateServiceProvider"/> method was called before,
+        /// it does not re-create it, but uses the previous one.
+        /// </summary>
         void Initialize();
     }
 }