ActiveRecord not saving after updating attribute
activerecord, json, ruby-on-rails
Solution
`will_change!`
You can also use:
test.json_data_will_change! # Goes before the save.
This will tell ActiveModel that the attribute, `json_data`, has changed (i.e. it's dirty ← there's a joke there somewhere) and will update the value properly on save.
See Rails is not saving an attribute that is changed for some more details as well.
Problem
I'm wondering if there is something at work here that I don't understand or if I've run into a bug in ActiveRecord (4.1.1). I have a database full of records with only one attribute, a field a bit of JSON in it. I take one and try to update it like so. ``` test = Submission.find(1) test.update_attribute('json_data',similar_but_different_json(test.json_data)) ``` Let's assume the method `similar_but_different_json` makes a small update to that JSON. In my case I'm fixing some data errors that were created by a broken form. When doing this, I don't get any errors, I show a commit in the console but no data submitted and get a return of `true`. In order to actually update the record I have to do this. ``` test = Submission.find(1) old_json_data = test.json_data test.json_data = "" test.json_data = similar_but_different_json(old_json_data) test.save ``` What seems to be happening is that ActiveRecord doesn't identify that a change has been made that has to be saved. Could this be why setting the field to an empty string then back to JSON allows the record to save?