I'm using PostgreSQL which supports arrays, which is very convenient. Sometimes I need to see if an element have been changed.
I know we can do this:
MyActiveRecordArray.changed?
=> true
But is there a way do this:
MyActiveRecordArray[0].changed?
Thank you for your answers and help!
Although you can't do it directly, you may use the changes method:
model = Model.new
model.array_field = [1]
model.changed?
=> true
model.changes['array_field']
=> [[], [1]]
doc: https://api.rubyonrails.org/classes/ActiveModel/Dirty.html#method-i-changes
Here is the solution I come up with, thanks to your answer
changes_index = []
old_array, new_array = model.changes['array_field']
new_array.each_with_index { |x, i| changes_index << i if x != old_array[i] }
You can ask directly your ActiveRecord instance if a specific attribute has changed by using attribute_name_changed? method.
On your case:
MyModel.active_record_array_changed?
This would return true or false depending whether the specific attribute has changed.