Ignoring Redis fields that are missing in the model?

[rgaufman]

When I change my model, any fields that are still present in Redis cause a NoMethodError, e.g.

> Device.all.entries[0]
Traceback (most recent call last):
        2: from (irb):5
        1: from (irb):5:in `entries'
NoMethodError (undefined method `created_at=' for #<Device:0x0000000004c48278 @attributes={}, @_memo={}>)

Is there any way to get Ohm to ignore any fields from Redis that are not in the model? - or is there some other recommended strategy to handle this?

[soveran]

@rgaufman I will work on this. I did some experiments in the past and it's true that those cases should be handled in a better way.

[carina-akaia]

irb(main):012:0> Transaction[3].remove NoMethodError: undefined method 'timestamp=' for #<Transaction:0x0000561b588b76e8>
I have the same problem when try to delete object with the attribute, deleted from model before

[pote]

Maybe just having more explicit exceptions that suggest the standard solution to the problem would be enough?

@katecanaveral this happens because you'd have to set to nil the attribute in all objects before you remove attribute :timestamp from your code, since the Transaction#timestamp and Transaction#timestamp= methods are defined by Ohm when attribute is present.

If I'm not mistaken, the process would be:

1. Set all Transaction#timestamp to nil - with a migration-like script or manually.
2. Remove attribute :timestamp.
3. Deploy the new code.

[carina-akaia]

@pote thanks for the solution