ValidationContext is always null

Question

User299025995 posted

Hi,

I'm using VS 2012 and I created an Asp.Net Dynamic Data Entities website with Entity Framework 5 DbContext.

I would like to perform validation reading some data from the DbContext so I created a custom validation attribute and I overriden IsValid method.
The problem is that validationContext parameter is always null.

I also tried to override DbContext SaveChanges to perform custom validation but it seems that SaveChanges isn't invoked.

How can I perform custom validation reading data from DbContext and having entity (validation context) that is being validated?

Answer 1

User-330204900 posted

Hi OasisLiveFor, I don;t do things liek that I get the saving changes event and then do my validation there are I always had issues doing things the other way.

Also I'm not sure that the Validation Context is for that can you post some sample code please?

Answer 2

User299025995 posted

public partial class TestDynamicDataEntitiesContext : DbContext
    {
        public TestDynamicDataEntitiesContext(string nameOrConnectionString)
            : base(nameOrConnectionString)
        {

            ObjectContext context = ((IObjectContextAdapter)this).ObjectContext;
            context.SavingChanges += Context_SavingChanges;
        }

        private void Context_SavingChanges(object sender, EventArgs e)
        {
            ObjectContext context = (ObjectContext)sender;
            TestDynamicDataEntities entities = new TestDynamicDataEntities();

            foreach (ObjectStateEntry entry in context.ObjectStateManager.GetObjectStateEntries(EntityState.Modified))
            {
                if (entry.Entity != null)
                {
                    if (entry.Entity.GetType() == typeof(#MyEntityType#))
                    {
						#MyEntityType# myEntity = entry.Entity as #MyEntityType#;
					
                        // Perform custom validation on myEntity reading from TestDynamicDataEntities context.
                    }
                }
            }

        }
    }

Hi,

I created a base class that inherits from DbContext and I changed t4 template to inherits form this custom base class. I attached to SavingChanges and perrmed custom validation.
Everything works fine.

Is this approach correct?

Answer 3

User697462465 posted

Hi OasisLive,

I suggest you to pass the ValidationContext you need to override DbContext.ValidateEntity(). The method takes two parameters - entity entry and items. You would pass your validation context in the items dictionary. Take a look at the "Customizing Validation" section of a blog :

 http://blogs.msdn.com/b/adonet/archive/2010/12/15/ef-feature-ctp5-validation.aspx

Hope this helps.

Best Regards,
Terry Guo

Answer 4

User299025995 posted

Hi,

ValidateEntity is not invoked.

As you can see from my previous post, I use DBContext but I register an ObjectContext in global.asax.cs:

 

 DefaultModel.RegisterContext(() =>
             {
                 return ((IObjectContextAdapter)new TestDynamicDataEntities()).ObjectContext;
             },