Feature: Add ApplyFilterAfterProjection option to control OData filter timing (#247)

* feature: add option apply filtering after projection

* No need to map the filter for projections.

---------

Co-authored-by: Amir Emil <[email protected]>
Co-authored-by: Blaise Taylor <[email protected]>

Author: 3 people

AutoMapper.AspNetCore.OData.EFCore/ProjectionSettings.cs

@@ -10,5 +10,6 @@ namespace AutoMapper.AspNet.OData
     public class ProjectionSettings
     {
         public object Parameters { get; set; }
+        public bool ApplyFilterAfterProjection { get; set; }
     }
 }

AutoMapper.AspNetCore.OData.EFCore/QueryableExtensions.cs

@@ -154,19 +154,24 @@ private static IQueryable<TModel> GetQuery<TModel, TData>(this IQueryable<TData>
             IEnumerable<Expression<Func<TModel, object>>> includeProperties = null,
             ProjectionSettings projectionSettings = null)
         {
-            Expression<Func<TData, bool>> f = mapper.MapExpression<Expression<Func<TData, bool>>>(filter);
             Func<IQueryable<TData>, IQueryable<TData>> mappedQueryFunc = mapper.MapExpression<Expression<Func<IQueryable<TData>, IQueryable<TData>>>>(queryFunc)?.Compile();
 
-            if (filter != null)
-                query = query.Where(f);
+            if (filter != null && !FilterAfterProjection())
+                query = query.Where(mapper.MapExpression<Expression<Func<TData, bool>>>(filter));
 
-            return mappedQueryFunc != null
+            var projectedQuery = mappedQueryFunc != null
                     ? mapper.ProjectTo(mappedQueryFunc(query), projectionSettings?.Parameters, GetIncludes())
                     : mapper.ProjectTo(query, projectionSettings?.Parameters, GetIncludes());
 
+            if (filter != null && FilterAfterProjection())
+                projectedQuery = projectedQuery.Where(filter);
+
+            return projectedQuery;
+
+            bool FilterAfterProjection() => projectionSettings?.ApplyFilterAfterProjection ?? false;
             Expression<Func<TModel, object>>[] GetIncludes() => includeProperties?.ToArray() ?? new Expression<Func<TModel, object>>[] { };
         }
-
+        
         private static void ApplyOptions<TModel, TData>(this IQueryable<TData> query, IMapper mapper, Expression<Func<TModel, bool>> filter, ODataQueryOptions<TModel> options, QuerySettings querySettings)
         {
             ApplyOptions(options, querySettings);

AutoMapper.OData.EFCore.Tests/GetQueryTests.cs

@@ -416,7 +416,85 @@ void Test(ICollection<OpsTenant> collection)
                 Assert.Equal("Two", collection.First().Name);
             }
         }
+        [Fact]
+        public async Task FilterByDynamicParameterValueAfterProjectionReturnExpectedResults()
+        {
+            // Arrange
+            string buildingParameterValue = Guid.NewGuid().ToString();
+
+            var parameters = new { buildingParameter = buildingParameterValue };
+
+            var projectionSettings = new ProjectionSettings
+            {
+                Parameters = parameters,
+                //if false test will fail
+                ApplyFilterAfterProjection = true
+            };
+
+            var odataSettings = new ODataSettings
+            {
+                HandleNullPropagation = HandleNullPropagationOption.False
+            };
+
+            string query = $"/corebuilding?$filter=Parameter eq '{buildingParameterValue}'";
+
+            // Act
+            var result = await GetAsync<CoreBuilding, TBuilding>(
+                query,
+                null,
+                new QuerySettings
+                {
+                    ProjectionSettings = projectionSettings,
+                    ODataSettings = odataSettings
+                });
+
+            // Assert
+            if (result.Count == 0)
+            {
+                throw new Xunit.Sdk.XunitException(
+                    "Expected at least one CoreBuilding with matching Parameter value, " +
+                    "but none were returned. This replicates the case where a runtime parameter " +
+                    "(like CurrentUserId) was not propagated during OData filter translation."
+                );
+            }
 
+            Assert.All(result, b => Assert.Equal(buildingParameterValue, b.Parameter));
+        }
+
+        [Fact]
+        public async Task FilterByDynamicParameterValueBeforeProjectionReturnZeroResults()
+        {
+            // Arrange
+            string buildingParameterValue = Guid.NewGuid().ToString();
+
+            var parameters = new { buildingParameter = buildingParameterValue };
+
+            var projectionSettings = new ProjectionSettings
+            {
+                Parameters = parameters,
+                ApplyFilterAfterProjection = false
+            };
+
+            var odataSettings = new ODataSettings
+            {
+                HandleNullPropagation = HandleNullPropagationOption.False
+            };
+
+            string query = $"/corebuilding?$filter=Parameter eq '{buildingParameterValue}'";
+
+            // Act
+            var result = await GetAsync<CoreBuilding, TBuilding>(
+                query,
+                null,
+                new QuerySettings
+                {
+                    ProjectionSettings = projectionSettings,
+                    ODataSettings = odataSettings
+                });
+
+            // Assert
+            Assert.Empty(result);
+        }
         [Fact]
         public async Task BuildingExpandBuilderTenantFilterEqAndOrderByWithParameter()
         {