private static ISelect <T1> IncludeLevel <T1>(this ISelect <T1> select, int level, TableRefTree tree, ParameterExpression parameterExpression = null, MemberExpression bodyExpression = null)
{
var includeMethod = select.GetType().GetMethod("Include");
var includeManyMethod = select.GetType().GetMethod("IncludeMany");
parameterExpression ??= Expression.Parameter(tree.TableInfo.Type, "t");
foreach (var sub in tree.Subs)
{
switch (sub.TableRef.RefType)
{
case TableRefType.ManyToOne:
case TableRefType.OneToOne:
{
var body = bodyExpression == null?Expression.Property(parameterExpression, sub.TableRef.Property) : Expression.Property(bodyExpression, sub.TableRef.Property);
if (sub.Subs.Count == 0)
{
var funcType = typeof(Func <,>).MakeGenericType(parameterExpression.Type, sub.TableRef.RefEntityType);
var navigateSelector = Expression.Lambda(funcType, body, parameterExpression);
includeMethod.MakeGenericMethod(sub.TableRef.RefEntityType).Invoke(select, new object[] { navigateSelector });
}
else
{
select.IncludeLevel(level, sub, parameterExpression, body);
}
}
break;
case TableRefType.ManyToMany:
case TableRefType.OneToMany:
{
var body = bodyExpression == null?Expression.Property(parameterExpression, sub.TableRef.Property) : Expression.Property(bodyExpression, sub.TableRef.Property);
object then = null;
if (sub.Subs.Count > 0)
{
//var thenSelectType = select.GetType().GetGenericTypeDefinition().MakeGenericType(sub.TableRef.RefEntityType);
var thenSelectType = typeof(ISelect <>).MakeGenericType(sub.TableRef.RefEntityType);
var thenType = typeof(Action <>).MakeGenericType(thenSelectType);
var thenParameter = Expression.Parameter(thenSelectType, "then");
var thenMethod = typeof(FreeSql_1113_Extensions).GetMethod(nameof(IncludeLevel)).MakeGenericMethod(sub.TableRef.RefEntityType);
var thenLevelConst = Expression.Constant(level - sub.Level + 1);
var thenBody = Expression.Call(null, thenMethod, thenParameter, thenLevelConst);
var thenExpression = Expression.Lambda(thenType, thenBody, thenParameter);
then = thenExpression.Compile();
}
var funcType = typeof(Func <,>).MakeGenericType(parameterExpression.Type, typeof(IEnumerable <>).MakeGenericType(sub.TableRef.RefEntityType));
var navigateSelector = Expression.Lambda(funcType, body, parameterExpression);
includeManyMethod.MakeGenericMethod(sub.TableRef.RefEntityType).Invoke(select, new object[] { navigateSelector, then });
}
break;
}
}
return(select);
}
public static ISelect <T1> IncludeLevel <T1>(this ISelect <T1> select, int level)
{
var tree = TableRefTree.GetTableRefTree(select, level);
return(select.IncludeLevel(level, tree));
}