Wrong foreign key field pass the validation if the field is optional

[AnastassiyaP]

It happens because get_model doesn't fail on DoesNotExist https://github.com/coleifer/wtf-peewee/blob/master/wtfpeewee/fields.py#L229

Could you please change this behavior?

[coleifer]

"It happens" -- what happens? Can you clarify? What are you wanting to happen?

[AnastassiyaP]

Happens that form.validate() returns True and then on saving the object, I get database error because foreign key constraint fails.
I want to get an error like "Object does not exist" if I pass the wrong param

[AnastassiyaP]

I have another issue with this
When I try to use custom validators on foreign key field, I get an error, because wtf-peewee redefines field.data as a property here https://github.com/coleifer/wtf-peewee/blob/master/wtfpeewee/fields.py#L233
So field.validate() tries to get object.data to validate, and gets the peewee object, if it exists. And empty string if does not.

[coleifer]

Hmm... As I recall the way wtforms manages field data and handles validation was really weird and I had to make many workarounds. Not sure? Can you create a failing test-case in the test-suite?

[AnastassiyaP]

Yes, sure.
Take a look, please, I created the commit that illustrates this two situations: https://github.com/coleifer/wtf-peewee/compare/master...AnastassiyaP:test_opt_fk?expand=1