Switch in readonly does not change when i change model

How can I do for change the state of the switch when the switch is in readonly.

For example my switch is linked with a model. If I change the model and my switch is not in readonly everything is OK, the state of my switch change.
But if my switch is in readonly and I change the model, the state of my switch does not change :(

http://embed.plnkr.co/I85Ddhyrm1tUVoLXjrFC/