CODEWITHSUNDEEP
c#.netwcflinq-to-sqldbml
Matthew James Davis
Matthew James Davis

Reputation: 12295

linq-to-sql won't serialize references

So I have a couple of tables in a linq-to-sql dbml file:

my dbml layout

I have set up a WCF REST get endpoint to user. I cannot get it to pass back a JSON structured like this:

{
    ID: '123',
    Username: 'fdsaf',
    ...
    Role: 
    {
        ID: '123',
        ...
    }
}

If I set the DBML serialization mode from "None" to "Unidirectional," I can get the user object without the role. If I leave the serialization mode on none and remove the association, I can also get the user object. As a sanity check, I can also get the role with no user. As soon as I try to include a reference, it attempts to serialize twice (in the debugger) and I get the following error after what appears to be a successful function call on the client:

client error

Additionally, I can get what I'm looking for if I open the association and turn the child property access to internal. However, I will sometimes want to pass back roles with collections of users, so this will not be sufficient.

insufficient workaround

I include this piece of information because it seems to indicate that the serializer is trying to serialize User > Role > User > Role ... etc., which is obviously insufficient. But there must be a middle ground between a circular and a zero-level-deep reference.

Code below:

using (DataContext context = new DataContext())
{
    DataLoadOptions opts = new DataLoadOptions();
    opts.LoadWith<User>(u => u.Role);
    context.LoadOptions = opts;

    return context.Users
        .Where(u => u.ID == id)
        .Where(u => u.Hash == hash)
        .FirstOrDefault();
}

Upvotes: 3

Views: 1222

Answers (1)

finman
finman

Reputation: 545

I would create a mapped object instead of a user and give it an array of roles, Mainly because you are passing back a raw data object which includes the password and raw hash of a user. You can then hide these in the mapping

Have one model for each, UserObject with a child of Roles and a RolesObject with a child of User.

Alternatively, have a property that you can serialize on each that will return pseudo objects so roles could be an array of id/strings and so could users (then you ignore serialization on the relationship and serialize that instead, no circular reference problems)

Upvotes: 1

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