PropertyForwardingInterceptor -> DirectiveInterceptor

Author: YuriyDurov

src/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/DirectiveInterceptorConfigurationBuilder.cs

@@ -0,0 +1,20 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace BitzArt.CA.Persistence;
+
+internal class DirectiveInterceptorConfigurationBuilder<TEntity>
+    (DirectiveInterceptor<TEntity> interceptor)
+    : IDirectiveInterceptorConfigurationBuilder<TEntity>
+    where TEntity : class
+{
+    DirectiveInterceptor<TEntity> IDirectiveInterceptorConfigurationBuilder<TEntity>.Interceptor => interceptor;
+
+    public IDirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty> Forward<TProperty>(Func<DbContext, TEntity, TProperty> originValueGetter)
+        => new DirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty>(this, originValueGetter);
+
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> Invoke(Action<DbContext, TEntity> action)
+    {
+        interceptor.AddDirective(action);
+        return this;
+    }
+}

src/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/DirectiveInterceptorForwardingRuleBuilder.cs

@@ -0,0 +1,19 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace BitzArt.CA.Persistence;
+
+internal class DirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty>
+    (IDirectiveInterceptorConfigurationBuilder<TEntity> builder, Func<DbContext, TEntity, TProperty> originValueGetter)
+    : IDirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty>
+    where TEntity : class
+{
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> To(Action<DbContext, TEntity, TProperty> targetValueSetter)
+    {
+        builder.Interceptor.AddDirective((dbContext, entity) =>
+        {
+            var value = originValueGetter.Invoke(dbContext, entity);
+            targetValueSetter.Invoke(dbContext, entity, value);
+        });
+        return builder;
+    }
+}

src/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/IDirectiveInterceptorConfigurationBuilder.cs

@@ -0,0 +1,54 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace BitzArt.CA.Persistence;
+
+/// <summary>
+/// Builder for configuring property forwarding rules.
+/// </summary>
+/// <typeparam name="TEntity">Entity type.</typeparam>
+public interface IDirectiveInterceptorConfigurationBuilder<TEntity>
+    where TEntity : class
+{
+    internal DirectiveInterceptor<TEntity> Interceptor { get; }
+
+    /// <inheritdoc/>
+    public IDirectiveInterceptorForwardingRuleBuilder<TEntity, object> Forward(string propertyName)
+        => Forward<object>(propertyName);
+
+    /// <summary>
+    /// Specifies the source property from which the value will be forwarded.
+    /// </summary>
+    /// <typeparam name="TProperty">Property type.</typeparam>
+    /// <param name="propertyName">Name of the property to get the value from.</param>
+    /// <returns><see cref="IDirectiveInterceptorForwardingRuleBuilder{TEntity, TProperty}"/> for further configuration.</returns>
+    public IDirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty> Forward<TProperty>(string propertyName)
+        => Forward((dbContext, entity) =>
+        {
+            var entry = dbContext.Entry(entity);
+            var property = entry.Property<TProperty>(propertyName);
+            return property.CurrentValue;
+        });
+
+    /// <inheritdoc cref="Forward{TProperty}(Func{DbContext, TEntity, TProperty})"/>
+    public IDirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty> Forward<TProperty>(Func<TEntity, TProperty> originValueGetter)
+        => Forward((_, entity) => originValueGetter(entity));
+
+    /// <summary>
+    /// Specifies the source property from which the value will be forwarded.
+    /// </summary>
+    /// <typeparam name="TProperty">Property type.</typeparam>
+    /// <param name="originValueGetter">Function to get the value from the source property.</param>
+    /// <returns><see cref="IDirectiveInterceptorForwardingRuleBuilder{TEntity, TProperty}"/> for further configuration.</returns>
+    public IDirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty> Forward<TProperty>(Func<DbContext, TEntity, TProperty> originValueGetter);
+
+    /// <inheritdoc cref="Invoke(Action{DbContext, TEntity})"/>
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> Invoke(Action<TEntity> action)
+        => Invoke((_, entity) => action(entity));
+
+    /// <summary>
+    /// Adds a custom action to be executed for each entity of type <typeparamref name="TEntity"/> being saved or updated.
+    /// </summary>
+    /// <param name="action">The action to execute.</param>
+    /// <returns><see cref="IDirectiveInterceptorConfigurationBuilder{TEntity}"/> to allow further configuration.</returns>
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> Invoke(Action<DbContext, TEntity> action);
+}

…ngInterceptorConfigurationRuleBuilder.cs …ctiveInterceptorForwardingRuleBuilder.cssrc/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/IPropertyForwardingInterceptorConfigurationRuleBuilder.cs renamed to src/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/IDirectiveInterceptorForwardingRuleBuilder.cs src/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/IPropertyForwardingInterceptorConfigurationRuleBuilder.cs renamed to src/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/IDirectiveInterceptorForwardingRuleBuilder.cs

@@ -9,15 +9,15 @@ namespace BitzArt.CA.Persistence;
 /// </summary>
 /// <typeparam name="TEntity">Entity type.</typeparam>
 /// <typeparam name="TProperty">Property type.</typeparam>
-public interface IPropertyForwardingInterceptorConfigurationRuleBuilder<TEntity, TProperty>
+public interface IDirectiveInterceptorForwardingRuleBuilder<TEntity, TProperty>
     where TEntity : class
 {
     /// <summary>
     /// Specifies the target property to which the value will be forwarded.
     /// </summary>
     /// <param name="propertyName">Name of the property to set the value to.</param>
-    /// <returns><see cref="IPropertyForwardingInterceptorConfigurationBuilder{TEntity}"/> to allow further configuration.</returns>
-    public IPropertyForwardingInterceptorConfigurationBuilder<TEntity> To(string propertyName)
+    /// <returns><see cref="IDirectiveInterceptorConfigurationBuilder{TEntity}"/> to allow further configuration.</returns>
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> To(string propertyName)
         => To((dbContext, entity, value) =>
         {
             var entry = dbContext.Entry(entity);
@@ -29,8 +29,8 @@ public IPropertyForwardingInterceptorConfigurationBuilder<TEntity> To(string pro
     /// Specifies the target property to which the value will be forwarded.
     /// </summary>
     /// <param name="targetPropertyExpression">Expression to specify the target property.</param>
-    /// <returns><see cref="IPropertyForwardingInterceptorConfigurationBuilder{TEntity}"/> to allow further configuration.</returns>
-    public IPropertyForwardingInterceptorConfigurationBuilder<TEntity> To(Expression<Func<TEntity, TProperty>> targetPropertyExpression)
+    /// <returns><see cref="IDirectiveInterceptorConfigurationBuilder{TEntity}"/> to allow further configuration.</returns>
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> To(Expression<Func<TEntity, TProperty>> targetPropertyExpression)
     {
         var memberExpression = targetPropertyExpression.Body as MemberExpression
             ?? throw new ArgumentException("The expression must be a member expression.", nameof(targetPropertyExpression));
@@ -48,13 +48,13 @@ public IPropertyForwardingInterceptorConfigurationBuilder<TEntity> To(Expression
     }
 
     /// <inheritdoc cref="To(Action{DbContext, TEntity, TProperty})"/>
-    public IPropertyForwardingInterceptorConfigurationBuilder<TEntity> To(Action<TEntity, TProperty> targetValueSetter)
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> To(Action<TEntity, TProperty> targetValueSetter)
         => To((_, entity, value) => targetValueSetter(entity, value));
 
     /// <summary>
     /// Specifies the target property to which the value will be forwarded.
     /// </summary>
     /// <param name="targetValueSetter">Action to set the value to the target property.</param>
-    /// <returns><see cref="IPropertyForwardingInterceptorConfigurationBuilder{TEntity}"/> to allow further configuration.</returns>
-    public IPropertyForwardingInterceptorConfigurationBuilder<TEntity> To(Action<DbContext, TEntity, TProperty> targetValueSetter);
+    /// <returns><see cref="IDirectiveInterceptorConfigurationBuilder{TEntity}"/> to allow further configuration.</returns>
+    public IDirectiveInterceptorConfigurationBuilder<TEntity> To(Action<DbContext, TEntity, TProperty> targetValueSetter);
 }

src/BitzArt.CA.Persistence.EntityFrameworkCore/Interceptors/PropertyForwarding/Configuration/IPropertyForwardingInterceptorConfigurationBuilder.cs

@@ -0,0 +1,49 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace BitzArt.CA.Persistence;
+
+/// <summary>
+/// An interceptor built using directives for handling entities of type <typeparamref name="TEntity"/>.
+/// </summary>
+public sealed class DirectiveInterceptor<TEntity> : OnSaveInterceptorBase
+    where TEntity : class
+{
+    private readonly List<Action<DbContext, TEntity>> _directives = [];
+
+    /// <summary>
+    /// Creates a new instance of <see cref="DirectiveInterceptor{TEntity}"/>.
+    /// </summary>
+    /// <param name="configure"></param>
+    public DirectiveInterceptor(Action<IDirectiveInterceptorConfigurationBuilder<TEntity>> configure)
+    {
+        var configurationBuilder = new DirectiveInterceptorConfigurationBuilder<TEntity>(this);
+        configure.Invoke(configurationBuilder);
+    }
+
+    /// <inheritdoc/>
+    protected override void OnSave(DbContext dbContext)
+    {
+        var entities = dbContext.ChangeTracker
+            .Entries<TEntity>()
+            .Where(e => e.State > EntityState.Unchanged)
+            .Select(e => e.Entity);
+
+        foreach (var entity in entities)
+        {
+            ApplyDirectives(dbContext, entity);
+        }
+    }
+
+    private void ApplyDirectives(DbContext dbContext, TEntity entity)
+    {
+        foreach (var rule in _directives)
+        {
+            rule.Invoke(dbContext, entity);
+        }
+    }
+
+    internal void AddDirective(Action<DbContext, TEntity> rule)
+    {
+        _directives.Add(rule);
+    }
+}