CODEWITHSUNDEEP
mdriven
Michael Q
Michael Q

Reputation: 71

Mdriven Designer class attribute Allow Null=False not working

I have a class named "Project" with attribute "Name" having type of String. I have changed it from Allow Null=True to False and then I have saved the model and restarted the WECPOF prototyper in xml mode. But it still allows me to create and save instances of Project without adding a name. What might I be doing wrong?

Upvotes: 1

Views: 44

Answers (2)

Lars
Lars

Reputation: 201

Try to keep your attributes "nullable", i.e. Allow null = True. Why? Because you usually end up wanting to see the difference between "nothing" and "empty".

As Hans suggested, add a contraint on the class with a expression like this "not self.Name.isNullOrEmpty".

Upvotes: 1

Hans Karlsen
Hans Karlsen

Reputation: 2435

I guess the string is not null but empty "". Strings are tricky that way - the only type that is presented the same as null and as its simplest possible value.

To signal to user that you do not allow a null or empty you can do a constraint on the class or add a validation expression in the ViewModel.

Upvotes: 1

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