ERP5Form: new gadget boolean option to serialize value to JSON
We have started to use Gadget fields in a project and for most of them, we have to exchange more than 1 text value with the client part. Currently, our TALES expressions are polluted with
JSON.parse calls on client side.
But the most important change in this commit is that it encourages to use proper serialization when needed (it's a common trap to do quick&dirty serialization, for example by joining/splitting with a particular char).
It's a small change and I doubt there would be a choice than JSON here.