CODEWITHSUNDEEP
mongodbmongodb-.net-driverneventstore
anon
anon

Reputation:

MongoDB Unknown discriminator value

I've added the code in the answer to this question: Unknown discriminator value 'MyEvent', but it didn't help.

An error occurred while deserializing the Body property of class EventStore.EventMessage: Unknown discriminator value : "Insert event name". Error only occurs when you try to rehydrate a saved object after program restart.

Running latest MyGet Build

Sample Repository:https://github.com/tonyeung/EventStore-MongoDB

To replicate the issue:

run the program
press c to create a new record
press q to quit
run the program again
but press r to rehydrate
error triggers

If you run the program, press c, press enter to continue, and press r to rehydrate without quitting, the object is rehydrated without a problem. WAT?

        using (var eventStore = WireupEventStore())
        {
            var snapshot = eventStore.Advanced.GetSnapshot(ID, int.MaxValue);
            if (snapshot == null)
            {
                // ERRORS HERE
                using (var stream = eventStore.OpenStream(ID, 0, int.MaxValue))
                {
                    var events = from s in stream.CommittedEvents
                                 select s.Body as IEvent;

                    obj.LoadsFromHistory(events);
                }
            }
        }

github issue: https://github.com/NEventStore/NEventStore/issues/203

Upvotes: 4

Views: 3931

Answers (1)

anon
anon

Reputation:

I figured it out, since I was using an interface as a marker for my events, I had to change the query from the SO question from

        var types = Assembly.GetAssembly(typeof(SimpleCQRS.Event))
                .GetTypes()
                .Where(type => type.IsSubclassOf(typeof(SimpleCQRS.Event)));

to

        var type = typeof(IEvent);
        var types = Assembly.GetAssembly(typeof(IEvent))
                .GetTypes()
                .Where(t => type.IsAssignableFrom(t))
                .Where(t => t.IsClass);

Upvotes: 4

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