v1.3.1

src/JsonApiDotNetCore/Controllers/JsonApiControllerMixin.cs

@@ -2,9 +2,9 @@
 
 namespace JsonApiDotNetCore.Controllers
 {
-    public class JsonApiControllerMixin : Controller
+    public abstract class JsonApiControllerMixin : Controller
     {
-        public JsonApiControllerMixin()
+        protected JsonApiControllerMixin()
         { }
 
         protected IActionResult UnprocessableEntity()

src/JsonApiDotNetCore/Data/DefaultEntityRepository.cs

@@ -56,10 +56,10 @@ public virtual IQueryable<TEntity> Filter(IQueryable<TEntity> entities,  FilterQ
             if(filterQuery == null)
                 return entities;
 
-            var attributeFilterQuery = new AttrFilterQuery(_jsonApiContext, filterQuery);
-
-            return entities
-                .Filter(attributeFilterQuery);
+            if(filterQuery.IsAttributeOfRelationship)
+                return entities.Filter(new RelatedAttrFilterQuery(_jsonApiContext, filterQuery));
+            else
+                return entities.Filter(new AttrFilterQuery(_jsonApiContext, filterQuery));
         }
 
         public virtual IQueryable<TEntity> Sort(IQueryable<TEntity> entities, List<SortQuery> sortQueries)

src/JsonApiDotNetCore/Extensions/IQueryableExtensions.cs

@@ -86,36 +86,7 @@ public static IQueryable<TSource> Filter<TSource>(this IQueryable<TSource> sourc
                 // {1}
                 var right = Expression.Constant(convertedValue, property.PropertyType);
 
-                Expression body;
-                switch (filterQuery.FilterOperation)
-                {
-                    case FilterOperations.eq:
-                        // {model.Id == 1}
-                        body = Expression.Equal(left, right);
-                        break;
-                    case FilterOperations.lt:
-                        // {model.Id < 1}
-                        body = Expression.LessThan(left, right);
-                        break;
-                    case FilterOperations.gt:
-                        // {model.Id > 1}
-                        body = Expression.GreaterThan(left, right);
-                        break;
-                    case FilterOperations.le:
-                        // {model.Id <= 1}
-                        body = Expression.LessThanOrEqual(left, right);
-                        break;
-                    case FilterOperations.ge:
-                        // {model.Id <= 1}
-                        body = Expression.GreaterThanOrEqual(left, right);
-                        break;
-                    case FilterOperations.like:
-                        // {model.Id <= 1}
-                        body = Expression.Call(left, "Contains", null, right);
-                        break;
-                    default:
-                        throw new JsonApiException("500", $"Unknown filter operation {filterQuery.FilterOperation}");
-                }
+                var body = GetFilterExpressionLambda(left, right, filterQuery.FilterOperation);
 
                 var lambda = Expression.Lambda<Func<TSource, bool>>(body, parameter);
 
@@ -126,27 +97,109 @@ public static IQueryable<TSource> Filter<TSource>(this IQueryable<TSource> sourc
                 throw new JsonApiException("400", $"Could not cast {filterQuery.PropertyValue} to {property.PropertyType.Name}");
             }
         }
+
+        public static IQueryable<TSource> Filter<TSource>(this IQueryable<TSource> source, RelatedAttrFilterQuery filterQuery)
+        {
+            if (filterQuery == null)
+                return source;
+
+            var concreteType = typeof(TSource);
+            var relation = concreteType.GetProperty(filterQuery.FilteredRelationship.InternalRelationshipName);
+            if (relation == null)
+                throw new ArgumentException($"'{filterQuery.FilteredRelationship.InternalRelationshipName}' is not a valid relationship of '{concreteType}'");
+
+            var relatedType = filterQuery.FilteredRelationship.Type;
+            var relatedAttr = relatedType.GetProperty(filterQuery.FilteredAttribute.InternalAttributeName);
+            if (relatedAttr == null)
+                throw new ArgumentException($"'{filterQuery.FilteredAttribute.InternalAttributeName}' is not a valid attribute of '{filterQuery.FilteredRelationship.InternalRelationshipName}'");
+
+            try
+            {
+                // convert the incoming value to the target value type
+                // "1" -> 1
+                var convertedValue = TypeHelper.ConvertType(filterQuery.PropertyValue, relatedAttr.PropertyType);
+                // {model}
+                var parameter = Expression.Parameter(concreteType, "model");
+
+                // {model.Relationship}
+                var leftRelationship = Expression.PropertyOrField(parameter, relation.Name);
+
+                // {model.Relationship.Attr}
+                var left = Expression.PropertyOrField(leftRelationship, relatedAttr.Name);
+
+                // {1}
+                var right = Expression.Constant(convertedValue, relatedAttr.PropertyType);
+
+                var body = GetFilterExpressionLambda(left, right, filterQuery.FilterOperation);
+
+                var lambda = Expression.Lambda<Func<TSource, bool>>(body, parameter);
+
+                return source.Where(lambda);
+            }
+            catch (FormatException)
+            {
+                throw new JsonApiException("400", $"Could not cast {filterQuery.PropertyValue} to {relatedAttr.PropertyType.Name}");
+            }
+        }
+
+        private static Expression GetFilterExpressionLambda(Expression left, Expression right, FilterOperations operation)
+        {
+            Expression body;
+            switch (operation)
+            {
+                case FilterOperations.eq:
+                    // {model.Id == 1}
+                    body = Expression.Equal(left, right);
+                    break;
+                case FilterOperations.lt:
+                    // {model.Id < 1}
+                    body = Expression.LessThan(left, right);
+                    break;
+                case FilterOperations.gt:
+                    // {model.Id > 1}
+                    body = Expression.GreaterThan(left, right);
+                    break;
+                case FilterOperations.le:
+                    // {model.Id <= 1}
+                    body = Expression.LessThanOrEqual(left, right);
+                    break;
+                case FilterOperations.ge:
+                    // {model.Id <= 1}
+                    body = Expression.GreaterThanOrEqual(left, right);
+                    break;
+                case FilterOperations.like:
+                    // {model.Id <= 1}
+                    body = Expression.Call(left, "Contains", null, right);
+                    break;
+                default:
+                    throw new JsonApiException("500", $"Unknown filter operation {operation}");
+            }
+
+            return body;
+        }
+
+
         public static IQueryable<TSource> Select<TSource>(this IQueryable<TSource> source, IEnumerable<string> columns)
         {
-            if(columns == null || columns.Count() == 0)
+            if (columns == null || columns.Count() == 0)
                 return source;
 
             var sourceType = source.ElementType;
-            
+
             var resultType = typeof(TSource);
 
             // {model}
             var parameter = Expression.Parameter(sourceType, "model");
-            
+
             var bindings = columns.Select(column => Expression.Bind(
                 resultType.GetProperty(column), Expression.PropertyOrField(parameter, column)));
-            
+
             // { new Model () { Property = model.Property } }
             var body = Expression.MemberInit(Expression.New(resultType), bindings);
-            
+
             // { model => new TodoItem() { Property = model.Property } }
             var selector = Expression.Lambda(body, parameter);
-            
+
             return source.Provider.CreateQuery<TSource>(
                 Expression.Call(typeof(Queryable), "Select", new Type[] { sourceType, resultType },
                 source.Expression, Expression.Quote(selector)));

src/JsonApiDotNetCore/Internal/DasherizedRoutingConvention.cs

@@ -1,5 +1,6 @@
 // REF: https://github.com/aspnet/Entropy/blob/dev/samples/Mvc.CustomRoutingConvention/NameSpaceRoutingConvention.cs
 // REF: https://github.com/aspnet/Mvc/issues/5691
+using JsonApiDotNetCore.Controllers;
 using JsonApiDotNetCore.Extensions;
 using Microsoft.AspNetCore.Mvc.ApplicationModels;
 
@@ -12,17 +13,25 @@ public DasherizedRoutingConvention(string nspace)
         {
             _namespace = nspace;
         }
-        
+
         public void Apply(ApplicationModel application)
         {
             foreach (var controller in application.Controllers)
-            {
-                var template = $"{_namespace}/{controller.ControllerName.Dasherize()}";
-                controller.Selectors[0].AttributeRouteModel = new AttributeRouteModel()
+            {                
+                if (IsJsonApiController(controller))
                 {
-                    Template = template
-                };
+                    var template = $"{_namespace}/{controller.ControllerName.Dasherize()}";
+                    controller.Selectors[0].AttributeRouteModel = new AttributeRouteModel()
+                    {
+                        Template = template
+                    };
+                }
             }
         }
+
+        private bool IsJsonApiController(ControllerModel controller)
+        {
+            return controller.ControllerType.IsSubclassOf(typeof(JsonApiControllerMixin));
+        }
     }
 }

src/JsonApiDotNetCore/Internal/Query/AttrFilterQuery.cs

@@ -1,51 +1,39 @@
-using System;
 using System.Linq;
 using JsonApiDotNetCore.Models;
 using JsonApiDotNetCore.Services;
 
 namespace JsonApiDotNetCore.Internal.Query
 {
-  public class AttrFilterQuery
-  {
-    private readonly IJsonApiContext _jsonApiContext;
-
-    public AttrFilterQuery(
-        IJsonApiContext jsonApiCopntext,
-        FilterQuery filterQuery)
-    {
-      _jsonApiContext = jsonApiCopntext;
-
-      var attribute = GetAttribute(filterQuery.Key);
-
-      if (attribute == null)
-        throw new JsonApiException("400", $"{filterQuery.Key} is not a valid property.");
-
-      FilteredAttribute = attribute;
-      PropertyValue = filterQuery.Value;
-      FilterOperation = GetFilterOperation(filterQuery.Operation);
-    }
-
-    public AttrAttribute FilteredAttribute { get; set; }
-    public string PropertyValue { get; set; }
-    public FilterOperations FilterOperation { get; set; }
-
-    private FilterOperations GetFilterOperation(string prefix)
-    {
-      if (prefix.Length == 0) return FilterOperations.eq;
-
-      FilterOperations opertion;
-      if (!Enum.TryParse<FilterOperations>(prefix, out opertion))
-        throw new JsonApiException("400", $"Invalid filter prefix '{prefix}'");
-
-      return opertion;
-    }
-
-    private AttrAttribute GetAttribute(string propertyName)
+    public class AttrFilterQuery : BaseFilterQuery
     {
-      return _jsonApiContext.RequestEntity.Attributes
-          .FirstOrDefault(attr =>
-              attr.InternalAttributeName.ToLower() == propertyName.ToLower()
-      );
+        private readonly IJsonApiContext _jsonApiContext;
+
+        public AttrFilterQuery(
+            IJsonApiContext jsonApiCopntext,
+            FilterQuery filterQuery)
+        {
+            _jsonApiContext = jsonApiCopntext;
+
+            var attribute = GetAttribute(filterQuery.Key);
+
+            if (attribute == null)
+                throw new JsonApiException("400", $"{filterQuery.Key} is not a valid property.");
+
+            FilteredAttribute = attribute;
+            PropertyValue = filterQuery.Value;
+            FilterOperation = GetFilterOperation(filterQuery.Operation);
+        }
+
+        public AttrAttribute FilteredAttribute { get; set; }
+        public string PropertyValue { get; set; }
+        public FilterOperations FilterOperation { get; set; }
+
+        private AttrAttribute GetAttribute(string propertyName)
+        {
+            return _jsonApiContext.RequestEntity.Attributes
+                .FirstOrDefault(attr =>
+                    attr.InternalAttributeName.ToLower() == propertyName.ToLower()
+            );
+        }
     }
-  }
 }

src/JsonApiDotNetCore/Internal/Query/BaseFilterQuery.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace JsonApiDotNetCore.Internal.Query
+{
+    public class BaseFilterQuery
+    {
+        protected FilterOperations GetFilterOperation(string prefix)
+        {
+            if (prefix.Length == 0) return FilterOperations.eq;
+
+            FilterOperations opertion;
+            if (!Enum.TryParse<FilterOperations>(prefix, out opertion))
+                throw new JsonApiException("400", $"Invalid filter prefix '{prefix}'");
+
+            return opertion;
+        }
+    }
+}

src/JsonApiDotNetCore/Internal/Query/FilterQuery.cs

@@ -12,5 +12,6 @@ public FilterQuery(string key, string value, string operation)
         public string Key { get; set; }
         public string Value { get; set; }
         public string Operation { get; set; }
+        public bool IsAttributeOfRelationship => Key.Contains(".");
     }
 }

src/JsonApiDotNetCore/Internal/Query/RelatedAttrFilterQuery.cs

@@ -0,0 +1,51 @@
+using System.Linq;
+using JsonApiDotNetCore.Models;
+using JsonApiDotNetCore.Services;
+
+namespace JsonApiDotNetCore.Internal.Query
+{
+    public class RelatedAttrFilterQuery : BaseFilterQuery
+    {
+        private readonly IJsonApiContext _jsonApiContext;
+
+        public RelatedAttrFilterQuery(
+            IJsonApiContext jsonApiCopntext,
+            FilterQuery filterQuery)
+        {
+            _jsonApiContext = jsonApiCopntext;
+
+            var relationshipArray = filterQuery.Key.Split('.');
+
+            var relationship = GetRelationship(relationshipArray[0]);
+            if (relationship == null)
+                throw new JsonApiException("400", $"{relationshipArray[0]} is not a valid relationship.");
+
+            var attribute = GetAttribute(relationship, relationshipArray[1]);
+            if (attribute == null)
+                throw new JsonApiException("400", $"{relationshipArray[1]} is not a valid attribute on {relationshipArray[0]}.");
+
+            FilteredRelationship = relationship;
+            FilteredAttribute = attribute;
+            PropertyValue = filterQuery.Value;
+            FilterOperation = GetFilterOperation(filterQuery.Operation);
+        }
+
+        public AttrAttribute FilteredAttribute { get; set; }
+        public string PropertyValue { get; set; }
+        public FilterOperations FilterOperation { get; set; }
+        public RelationshipAttribute FilteredRelationship { get; private set; }
+
+        private RelationshipAttribute GetRelationship(string propertyName)
+        {
+            return _jsonApiContext.RequestEntity.Relationships
+              .FirstOrDefault(r => r.InternalRelationshipName.ToLower() == propertyName.ToLower());
+        }
+
+        private AttrAttribute GetAttribute(RelationshipAttribute relationship, string attribute)
+        {
+            var relatedContextExntity = _jsonApiContext.ContextGraph.GetContextEntity(relationship.Type);
+            return relatedContextExntity.Attributes
+              .FirstOrDefault(a => a.InternalAttributeName.ToLower() == attribute.ToLower());
+        }
+    }
+}

src/JsonApiDotNetCore/JsonApiDotNetCore.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <VersionPrefix>1.3.0</VersionPrefix>
+    <VersionPrefix>1.3.1</VersionPrefix>
     <TargetFramework>netcoreapp1.0</TargetFramework>
     <AssemblyName>JsonApiDotNetCore</AssemblyName>
     <PackageId>JsonApiDotNetCore</PackageId>