private MethodInfo GetExpandMethodInfo <TElement, TTarget>(Expression <Func <TElement, TTarget> > navigationPropertyAccessor)
{
var dsq = (DataServiceQuery <TElement>)DbFixtureInitDb.GetQuerableOe(_container, navigationPropertyAccessor.Parameters[0].Type);
Func <Expression <Func <TElement, TTarget> >, DataServiceQuery <TElement> > expand = dsq.Expand;
return(expand.GetMethodInfo());
}
protected override Expression VisitMember(MemberExpression node)
{
if (node.Expression is ConstantExpression && node.Type.IsGenericType && node.Type.GetGenericTypeDefinition() == typeof(IQueryable <>))
{
Type entityType = node.Type.GetGenericArguments()[0];
IQueryable source = DbFixtureInitDb.GetQuerableOe(_container, entityType);
return(source.Expression);
}
return(Expression.MakeMemberAccess(base.Visit(node.Expression), Map(node.Member)));
}
protected override Expression VisitParameter(ParameterExpression node)
{
if (typeof(IQueryable).IsAssignableFrom(node.Type))
{
Type entityType = node.Type.GetGenericArguments()[0];
IQueryable source = DbFixtureInitDb.GetQuerableOe(_container, entityType);
return(source.Expression);
}
if (_parameters.TryGetValue(node, out ParameterExpression parameter))
{
return(parameter);
}
parameter = Expression.Parameter(Map(node.Type), node.Name);
_parameters.Add(node, parameter);
return(parameter);
}