public QueryableBuilder(Expression source, Type elementType, Type extensionType, LambdaParameterNameFactory nameFactory,
IResourceFactory resourceFactory, IResourceContextProvider resourceContextProvider, IModel entityModel,
LambdaScopeFactory lambdaScopeFactory = null)
{
_source = source ?? throw new ArgumentNullException(nameof(source));
_elementType = elementType ?? throw new ArgumentNullException(nameof(elementType));
_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));
_entityModel = entityModel ?? throw new ArgumentNullException(nameof(entityModel));
_lambdaScopeFactory = lambdaScopeFactory ?? new LambdaScopeFactory(_nameFactory);
}
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));
}
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 = collectionProperty.PropertyType.ToConcreteCollectionType();
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 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));
}