Where is Rails Validations Value Hash Initialization?

rubyonrails-talk
1

I have run into a problem with Rails "validates_uniqueness_of". The evidence indicates that this method does not get attribute values set in the model but rather uses raw data passed from the view. I have traced through the process with the debugger but my knowledge of rails internals is too sketchy for me to pinpoint where and how the value initialization is taking place.

The symptom of the difficulty is demonstrated below. Given an input string for @entity.entity_name of "A TEST CLIENT" the model invokes an override on the default accessors to produce a final string of entity.entity_name = "a test client". The validates_uniqueness_of :entity_name for the above situation passes even if "a test client" is already on file but the subsequent SQL INSERT statement generated fails because the value passed is "a test client" and this triggers an SQL exception because of an INDEX UNIQUE constraint on that column.

My questions are these:

1. Why does the validation_uniqueness_of NOT use the value that is going to be inserted into the database for its check?

2. Is this a feature or a bug?

3. Where is this value passed to validate_uniqueness_of if not from the model; from the controller?

4. Do I have to replicate model code in the controller to achieve the effect desired, a validation check using the values that will be used for insertion?

X-Posted to WWR-Forum

2

I found the source of my confusion. I had redefined the getter method for entity_name to provide a titlecase display to the view. It is this value that the validates_uniqueness_of is using, which is different than the value provided from the overloaded setter method (keycase).

I am still not sure why the validates would use a value from one source for validation and a value from another source for the actual update but at least I can now get this to work.

3

James Byrne wrote:

I am still not sure why the validates would use a value from one source for validation and a value from another source for the actual update but at least I can now get this to work.

Evidently, I was up too late chasing this down and did not have enough coffee this morning to wake me. Of course the validator is going to take the value from the attribute getter and of course it is my job to make sure that the getter and setter say the same things.

Sigh...