private Expression CreateLambdaBodyInitializer(IDictionary <ResourceFieldAttribute, QueryLayer> selectors, ResourceContext resourceContext,
LambdaScope lambdaScope, bool lambdaAccessorRequiresTestForNull)
{
var propertySelectors = ToPropertySelectors(selectors, resourceContext, lambdaScope.Parameter.Type);
MemberBinding[] propertyAssignments = propertySelectors.Select(selector => CreatePropertyAssignment(selector, lambdaScope)).Cast <MemberBinding>().ToArray();
NewExpression newExpression = _resourceFactory.CreateNewExpression(lambdaScope.Accessor.Type);
Expression memberInit = Expression.MemberInit(newExpression, propertyAssignments);
if (lambdaScope.HasManyThrough != null)
{
MemberBinding outerPropertyAssignment = Expression.Bind(lambdaScope.HasManyThrough.RightProperty, memberInit);
NewExpression outerNewExpression = _resourceFactory.CreateNewExpression(lambdaScope.HasManyThrough.ThroughType);
memberInit = Expression.MemberInit(outerNewExpression, outerPropertyAssignment);
}
if (!lambdaAccessorRequiresTestForNull)
{
return(memberInit);
}
return(TestForNull(lambdaScope.Accessor, memberInit));
}
public override Expression VisitCollectionNotEmpty(CollectionNotEmptyExpression expression, Type argument)
{
Expression property = Visit(expression.TargetCollection, argument);
Type elementType = CollectionConverter.TryGetCollectionElementType(property.Type);
if (elementType == null)
{
throw new InvalidOperationException("Expression must be a collection.");
}
Expression predicate = null;
if (expression.Filter != null)
{
var hasManyThrough = expression.TargetCollection.Fields.Last() as HasManyThroughAttribute;
var lambdaScopeFactory = new LambdaScopeFactory(_nameFactory, hasManyThrough);
using LambdaScope lambdaScope = lambdaScopeFactory.CreateScope(elementType);
var builder = new WhereClauseBuilder(property, lambdaScope, typeof(Enumerable), _nameFactory);
predicate = builder.GetPredicateLambda(expression.Filter);
}
return(AnyExtensionMethodCall(elementType, property, predicate));
}
private Expression CreateCollectionInitializer(LambdaScope lambdaScope, PropertyInfo collectionProperty,
Type elementType, QueryLayer layer, LambdaScopeFactory lambdaScopeFactory)
{
MemberExpression propertyExpression = Expression.Property(lambdaScope.Accessor, collectionProperty);
var builder = new QueryableBuilder(propertyExpression, elementType, typeof(Enumerable), _nameFactory,
_resourceFactory, _resourceContextProvider, _entityModel, lambdaScopeFactory);
Expression layerExpression = builder.ApplyQuery(layer);
Type enumerableOfElementType = typeof(IEnumerable <>).MakeGenericType(elementType);
Type typedCollection = TypeHelper.ToConcreteCollectionType(collectionProperty.PropertyType);
ConstructorInfo typedCollectionConstructor = typedCollection.GetConstructor(new[]
{
enumerableOfElementType
});
if (typedCollectionConstructor == null)
{
throw new Exception(
$"Constructor on '{typedCollection.Name}' that accepts '{enumerableOfElementType.Name}' not found.");
}
return(Expression.New(typedCollectionConstructor, layerExpression));
}
private Expression CreateCollectionInitializer(LambdaScope lambdaScope, PropertyInfo collectionProperty, Type elementType, QueryLayer layer,
LambdaScopeFactory lambdaScopeFactory)
{
MemberExpression propertyExpression = Expression.Property(lambdaScope.Accessor, collectionProperty);
var builder = new QueryableBuilder(propertyExpression, elementType, typeof(Enumerable), _nameFactory, _resourceFactory, _resourceContextProvider,
_entityModel, lambdaScopeFactory);
Expression layerExpression = builder.ApplyQuery(layer);
// Earlier versions of EF Core 3.x failed to understand `query.ToHashSet()`, so we emit `new HashSet(query)` instead.
// Interestingly, EF Core 5 RC1 fails to understand `new HashSet(query)`, so we emit `query.ToHashSet()` instead.
// https://github.com/dotnet/efcore/issues/22902
if (EntityFrameworkCoreSupport.Version.Major < 5)
{
Type enumerableOfElementType = typeof(IEnumerable <>).MakeGenericType(elementType);
Type typedCollection = CollectionConverter.ToConcreteCollectionType(collectionProperty.PropertyType);
ConstructorInfo typedCollectionConstructor = typedCollection.GetConstructor(enumerableOfElementType.AsArray());
if (typedCollectionConstructor == null)
{
throw new InvalidOperationException($"Constructor on '{typedCollection.Name}' that accepts '{enumerableOfElementType.Name}' not found.");
}
return(Expression.New(typedCollectionConstructor, layerExpression));
}
string operationName = CollectionConverter.TypeCanContainHashSet(collectionProperty.PropertyType) ? "ToHashSet" : "ToList";
return(CopyCollectionExtensionMethodCall(layerExpression, operationName, elementType));
}
public IncludeClauseBuilder(Expression source, LambdaScope lambdaScope, ResourceContext resourceContext,
IResourceContextProvider resourceContextProvider)
: base(lambdaScope)
{
_source = source ?? throw new ArgumentNullException(nameof(source));
_resourceContext = resourceContext ?? throw new ArgumentNullException(nameof(resourceContext));
_resourceContextProvider = resourceContextProvider ?? throw new ArgumentNullException(nameof(resourceContextProvider));
}
protected virtual Expression ApplyFilter(Expression source, FilterExpression filter)
{
using LambdaScope lambdaScope = _lambdaScopeFactory.CreateScope(_elementType);
var builder = new WhereClauseBuilder(source, lambdaScope, _extensionType, _nameFactory);
return(builder.ApplyWhere(filter));
}
protected virtual Expression ApplyInclude(Expression source, IncludeExpression include, ResourceContext resourceContext)
{
using LambdaScope lambdaScope = _lambdaScopeFactory.CreateScope(_elementType);
var builder = new IncludeClauseBuilder(source, lambdaScope, resourceContext, _resourceContextProvider);
return(builder.ApplyInclude(include));
}
protected virtual Expression ApplyPagination(Expression source, PaginationExpression pagination)
{
using LambdaScope lambdaScope = _lambdaScopeFactory.CreateScope(_elementType);
var builder = new SkipTakeClauseBuilder(source, lambdaScope, _extensionType);
return(builder.ApplySkipTake(pagination));
}
protected virtual Expression ApplySort(Expression source, SortExpression sort)
{
using LambdaScope lambdaScope = _lambdaScopeFactory.CreateScope(_elementType);
var builder = new OrderClauseBuilder(source, lambdaScope, _extensionType);
return(builder.ApplyOrderBy(sort));
}
public WhereClauseBuilder(Expression source, LambdaScope lambdaScope, Type extensionType)
: base(lambdaScope)
{
ArgumentGuard.NotNull(source, nameof(source));
ArgumentGuard.NotNull(extensionType, nameof(extensionType));
_source = source;
_extensionType = extensionType;
}
protected virtual Expression ApplyProjection(Expression source, IDictionary <ResourceFieldAttribute, QueryLayer> projection,
ResourceContext resourceContext)
{
using LambdaScope lambdaScope = _lambdaScopeFactory.CreateScope(_elementType);
var builder = new SelectClauseBuilder(source, lambdaScope, _entityModel, _extensionType, _nameFactory, _resourceFactory, _resourceContextProvider);
return(builder.ApplySelect(projection, resourceContext));
}
public SelectClauseBuilder(Expression source, LambdaScope lambdaScope, IModel entityModel, Type extensionType,
LambdaParameterNameFactory nameFactory, IResourceFactory resourceFactory, IResourceContextProvider resourceContextProvider)
: base(lambdaScope)
{
_source = source ?? throw new ArgumentNullException(nameof(source));
_entityModel = entityModel ?? throw new ArgumentNullException(nameof(entityModel));
_extensionType = extensionType ?? throw new ArgumentNullException(nameof(extensionType));
_nameFactory = nameFactory ?? throw new ArgumentNullException(nameof(nameFactory));
_resourceFactory = resourceFactory ?? throw new ArgumentNullException(nameof(resourceFactory));
_resourceContextProvider = resourceContextProvider ?? throw new ArgumentNullException(nameof(resourceContextProvider));
}
public WhereClauseBuilder(Expression source, LambdaScope lambdaScope, Type extensionType, LambdaParameterNameFactory nameFactory)
: base(lambdaScope)
{
ArgumentGuard.NotNull(source, nameof(source));
ArgumentGuard.NotNull(extensionType, nameof(extensionType));
ArgumentGuard.NotNull(nameFactory, nameof(nameFactory));
_source = source;
_extensionType = extensionType;
_nameFactory = nameFactory;
}
public IncludeClauseBuilder(Expression source, LambdaScope lambdaScope, ResourceContext resourceContext,
IResourceContextProvider resourceContextProvider)
: base(lambdaScope)
{
ArgumentGuard.NotNull(source, nameof(source));
ArgumentGuard.NotNull(resourceContext, nameof(resourceContext));
ArgumentGuard.NotNull(resourceContextProvider, nameof(resourceContextProvider));
_source = source;
_resourceContext = resourceContext;
_resourceContextProvider = resourceContextProvider;
}
private MemberAssignment CreatePropertyAssignment(PropertySelector selector, LambdaScope lambdaScope)
{
MemberExpression propertyAccess = Expression.Property(lambdaScope.Accessor, selector.Property);
Expression assignmentRightHandSide = propertyAccess;
if (selector.NextLayer != null)
{
HasManyThroughAttribute hasManyThrough = selector.OriginatingField as HasManyThroughAttribute;
var lambdaScopeFactory = new LambdaScopeFactory(_nameFactory, hasManyThrough);
assignmentRightHandSide = CreateAssignmentRightHandSideForLayer(selector.NextLayer, lambdaScope, propertyAccess,
selector.Property, lambdaScopeFactory);
}
return(Expression.Bind(selector.Property, assignmentRightHandSide));
}
public SelectClauseBuilder(Expression source, LambdaScope lambdaScope, IModel entityModel, Type extensionType, LambdaParameterNameFactory nameFactory,
IResourceFactory resourceFactory, IResourceContextProvider resourceContextProvider)
: base(lambdaScope)
{
ArgumentGuard.NotNull(source, nameof(source));
ArgumentGuard.NotNull(entityModel, nameof(entityModel));
ArgumentGuard.NotNull(extensionType, nameof(extensionType));
ArgumentGuard.NotNull(nameFactory, nameof(nameFactory));
ArgumentGuard.NotNull(resourceFactory, nameof(resourceFactory));
ArgumentGuard.NotNull(resourceContextProvider, nameof(resourceContextProvider));
_source = source;
_entityModel = entityModel;
_extensionType = extensionType;
_nameFactory = nameFactory;
_resourceFactory = resourceFactory;
_resourceContextProvider = resourceContextProvider;
}
private Expression CreateAssignmentRightHandSideForLayer(QueryLayer layer, LambdaScope outerLambdaScope, MemberExpression propertyAccess,
PropertyInfo selectorPropertyInfo, LambdaScopeFactory lambdaScopeFactory)
{
Type collectionElementType = TypeHelper.TryGetCollectionElementType(selectorPropertyInfo.PropertyType);
Type bodyElementType = collectionElementType ?? selectorPropertyInfo.PropertyType;
if (collectionElementType != null)
{
return(CreateCollectionInitializer(outerLambdaScope, selectorPropertyInfo, bodyElementType, layer, lambdaScopeFactory));
}
if (layer.Projection == null || !layer.Projection.Any())
{
return(propertyAccess);
}
using var scope = lambdaScopeFactory.CreateScope(bodyElementType, propertyAccess);
return(CreateLambdaBodyInitializer(layer.Projection, layer.ResourceContext, scope, true));
}
protected QueryClauseBuilder(LambdaScope lambdaScope)
{
ArgumentGuard.NotNull(lambdaScope, nameof(lambdaScope));
LambdaScope = lambdaScope;
}
public OrderClauseBuilder(Expression source, LambdaScope lambdaScope, Type extensionType)
: base(lambdaScope)
{
_source = source ?? throw new ArgumentNullException(nameof(source));
_extensionType = extensionType ?? throw new ArgumentNullException(nameof(extensionType));
}
protected QueryClauseBuilder(LambdaScope lambdaScope)
{
LambdaScope = lambdaScope ?? throw new ArgumentNullException(nameof(lambdaScope));
}