Support passing function type in request instead of hardcoded __callback()

[axic]

This would allow clean separation of unrelated callbacks.

See "example that uses external function types" here: http://solidity.readthedocs.io/en/develop/types.html#function-types

Also as of 0.4.10, the address of the function type can be easily retrieved by typecasting to address to allow further verification if needed.

[D-Nice]

@axic The callback with this implementation is forced to be an either or external/internal type. It of course would need to be an external type to be a proper callback, how then are you supposed to pass along this external function type to the API, if the originating contract is unable to actually see the callback (shows up as 'Undeclared identifier'), as it's forced to be external?

[axic]

if the originating contract is unable to actually see the callback (shows up as 'Undeclared identifier'), as it's forced to be external?

It can be looked up via this.<name> in the contract. However, this should be improved at some point in the future 😉

[D-Nice]

Ah ok, thanks :)

[bertani]

Just to give a quick update on this, we have decided to postpone the implementation of this feature in production as it could lead to extra complexity and we do not believe that there is enough user demand for this.

[D-Nice]

This was available on the contract side of our connector for a while, but never enabled within the backend infrastructure. Due to some new updates, the custom callback functionality has been removed, as it was using up major codespace, which was needed for other new features, and if there is interest, may be re-included in a future iteration.