private ExpressionInfo FetchFromPath(ExpressionInfo expressionInfo, string path, bool root)
{
var expression = expressionInfo.Expression;
var currentType = Type;
var metas = Session.Factory.GetAllClassMetadata()
.Select(o => o.Value)
.Where(o => Type.IsAssignableFrom(o.MappedClass))
.ToList();
if (!metas.Any())
{
throw new HibernateException($"Metadata for type '{Type}' was not found");
}
var meta = metas.Count == 1 ? metas.First() : metas.First(x => x.MappedClass == Type);
var paths = path.Split('.');
var index = 0;
foreach (var propName in paths)
{
if (meta == null)
{
throw new InvalidOperationException($"Unable to fetch property {propName} from path '{path}', no class metadata found");
}
var propType = meta.GetPropertyType(propName);
if (propType == null)
{
throw new Exception($"Property '{propName}' does not exist in the type '{meta.MappedClass.FullName}'");
}
if (!(propType is IAssociationType assocType))
{
throw new Exception($"Property '{propName}' does not implement IAssociationType interface");
}
if (assocType.IsCollectionType)
{
var collectionType = assocType as CollectionType;
var collectionPersister = (IQueryableCollection)Session.Factory.GetCollectionPersister(collectionType.Role);
meta = collectionPersister.ElementType.IsEntityType
? Session.Factory.GetClassMetadata(collectionPersister.ElementPersister.EntityName)
: null;
var collPath = string.Join(".", paths.Take(index + 1));
//Check if we can fetch the collection without create a cartesian product
//Fetch can occur only for nested collection
if (!string.IsNullOrEmpty(expressionInfo.CollectionPath) &&
!collPath.StartsWith(expressionInfo.CollectionPath + "."))
{
//We have to continue fetching within a new base query
var nextQueryInfo = expressionInfo.GetOrCreateNext();
return(FetchFromPath(nextQueryInfo, path, true));
}
expressionInfo.CollectionPath = collPath;
}
else
{
meta = Session.Factory.GetClassMetadata(assocType.GetAssociatedEntityName(Session.Factory));
}
MethodInfo fetchMethod;
//Try to get the actual property type (so we can skip casting as relinq will throw an exception)
var relatedProp = currentType.GetProperty(propName);
var relatedType = relatedProp != null ? relatedProp.PropertyType : meta?.MappedClass;
if (propType.IsCollectionType && relatedProp != null && relatedType.IsGenericType)
{
relatedType = propType.GetType().IsAssignableToGenericType(typeof(GenericMapType <,>))
? typeof(KeyValuePair <,>).MakeGenericType(relatedType.GetGenericArguments())
: relatedType.GetGenericArguments()[0];
}
var convertToType = propType.IsCollectionType
? typeof(IEnumerable <>).MakeGenericType(relatedType)
: null;
var propertyExpression = CreatePropertyExpression(currentType, propName, convertToType);
//No fetch before
if (root)
{
fetchMethod = propType.IsCollectionType
? FetchManyMethod.MakeGenericMethod(Type, relatedType)
: FetchMethod.MakeGenericMethod(Type, relatedType);
}
else
{
fetchMethod = propType.IsCollectionType
? ThenFetchManyMethod.MakeGenericMethod(Type, currentType, relatedType)
: ThenFetchMethod.MakeGenericMethod(Type, currentType, relatedType);
}
expression = Expression.Call(fetchMethod, expression, propertyExpression);
currentType = relatedType;
index++;
root = false;
}
expressionInfo.Expression = expression;
return(expressionInfo);
}
private ExpressionInfo FetchFromPath(ExpressionInfo expressionInfo, string path)
{
var meta = expressionInfo.Metadata;
var root = true;
var expression = expressionInfo.Expression;
var currentType = Type;
string collectionPath = null;
var includedPaths = new List <string>();
var paths = path.Split('.');
var index = 0;
foreach (var propName in paths)
{
if (meta == null)
{
throw new InvalidOperationException($"Unable to fetch property {propName} from path '{path}', no class metadata found");
}
var propType = meta.GetPropertyType(propName);
if (propType == null)
{
throw new Exception($"Property '{propName}' does not exist in the type '{meta.MappedClass.FullName}'");
}
if (!(propType is IAssociationType assocType))
{
throw new Exception($"Property '{propName}' does not implement IAssociationType interface");
}
if (_includeOptions.IgnoreIncludedRelationFunction?.Invoke(Session.Factory, assocType) == true)
{
break;
}
IQueryableCollection collectionPersister = null;
if (assocType.IsCollectionType)
{
var collectionType = (CollectionType)assocType;
collectionPersister = (IQueryableCollection)Session.Factory.GetCollectionPersister(collectionType.Role);
meta = collectionPersister.ElementType.IsEntityType
? Session.Factory.GetClassMetadata(collectionPersister.ElementPersister.EntityName)
: null; // Will happen for dictionaries
var collPath = string.Join(".", paths.Take(index + 1));
//Check if we can fetch the collection without create a cartesian product
//Fetch can occur only for nested collection
if (!string.IsNullOrEmpty(expressionInfo.CollectionPath) &&
!collPath.StartsWith(expressionInfo.CollectionPath + "."))
{
//We have to continue fetching within a new base query
return(FetchFromPath(expressionInfo.GetOrCreateNext(), path));
}
collectionPath = collPath;
}
else
{
meta = Session.Factory.GetClassMetadata(assocType.GetAssociatedEntityName(Session.Factory));
}
var includedPath = expressionInfo.AddIncludedProperty(propName, meta, collectionPersister, root);
if (includedPath != null)
{
includedPaths.Add(includedPath);
}
MethodInfo fetchMethod;
//Try to get the actual property type (so we can skip casting as relinq will throw an exception)
var relatedProp = currentType.GetProperty(propName);
var relatedType = relatedProp != null ? relatedProp.PropertyType : meta?.MappedClass;
if (propType.IsCollectionType && relatedProp != null && relatedType.IsGenericType)
{
relatedType = propType.GetType().IsAssignableToGenericType(typeof(GenericMapType <,>))
? typeof(KeyValuePair <,>).MakeGenericType(relatedType.GetGenericArguments())
: relatedType.GetGenericArguments()[0];
}
var convertToType = propType.IsCollectionType
? typeof(IEnumerable <>).MakeGenericType(relatedType)
: null;
var propertyExpression = CreatePropertyExpression(currentType, propName, convertToType);
//No fetch before
if (root)
{
fetchMethod = propType.IsCollectionType
? FetchManyMethod.MakeGenericMethod(Type, relatedType)
: FetchMethod.MakeGenericMethod(Type, relatedType);
}
else
{
fetchMethod = propType.IsCollectionType
? ThenFetchManyMethod.MakeGenericMethod(Type, currentType, relatedType)
: ThenFetchMethod.MakeGenericMethod(Type, currentType, relatedType);
}
expression = Expression.Call(fetchMethod, expression, propertyExpression);
currentType = relatedType;
index++;
root = false;
}
if (_includeOptions.MaximumColumnsPerQuery.HasValue &&
expressionInfo.TotalColumns > _includeOptions.MaximumColumnsPerQuery.Value &&
expressionInfo.IsExpressionModified)
{
// Remove the included paths as we have to rebuild the expression from start
foreach (var includedPath in includedPaths)
{
expressionInfo.RemoveIncludedProperty(includedPath);
}
return(FetchFromPath(expressionInfo.GetOrCreateNext(), path));
}
if (!string.IsNullOrEmpty(collectionPath))
{
expressionInfo.CollectionPath = collectionPath;
}
expressionInfo.Expression = expression;
return(expressionInfo);
}
private ExpressionInfo FetchFromPath(ExpressionInfo expressionInfo, string path)
{
return(FetchFromPath(expressionInfo, path, true));
}
