Validate delete in WCF RIA service

[Henk]

Hi,

In the implementation of the delete method on an OA WCF RIA service I want to check if a value of a property of the object to delete has a specific value to check if the user has the rights to delete the object. If the user doesn't have the rights to delete the object I want to raise an exception. But if I try to read a value of a property of the object to delete in this method I get an exception that I cannot read values from objects which are marked for deletion. How can I achieve this?

Kind Regards.

[Jan Blessenohl]

Hello Henk,
that is a little tricky. Our Ria provider uses the empty ctor of the context class. To get it working you have to implement this ctor differently.
1. Add a new class derived from the generated context class and implement it like this:

namespace SilverlightApplication2.Web
{
    public partial class NorthwindEntityDiagramsSpecial : NorthwindEntityDiagrams
    {
        public NorthwindEntityDiagramsSpecial(bool readAfterDelete) : base()
        {
            GetScope().TransactionProperties.ReadAfterDelete = readAfterDelete;
        }
        public NorthwindEntityDiagramsSpecial() : this(true)
        {
            // used by OpenAccess Ria provider
        }
    }
}

Now open the Ria tt file and change the line:

string contextTypeName = "NorthwindEntityDiagrams";

to

string contextTypeName = "NorthwindEntityDiagramsSpecial";

after saving the tt file your Ria provider should use the new ctor and the additional setting.

Best wishes,
Jan Blessenohl
the Telerik team