[PATCH] Add priorities to components

[Paolo Capriotti]

This patch adds support for priorities in components. Whenever a component declares to implement an extension point interface, it can specify a priority. Components are then ordered (hence retrieved) by priorities. The syntax is:

class MyComponent(Component):
  implements(IRequestHandler, priority = -5)

The priority must be an integer (or convertible to integer), and applies to all interfaces in the implements function call. If not specified is considered to be 0. A lower number means higher priority. In the example, MyComponent has a higher priority than any built-in request handler, hence its match_request method ends up being called first.

[Noah Kantrowitz]

There are already workarounds for this, though they should be considered hacks at best. -1.

[Christopher Lenz]

Though I do think there's a problem here that may need to be properly addressed at some point, hardcoding a numeric priority in components is not a proper solution, in my humble opinion. We'd need something more dynamic that can be influenced by the user/admin, because that's where the conflicts are going to come up.

[Christian Boos]

Paolo, when an ordering is actually required among specific components, we already have a mechanism for this: trac.config.OrderedExtensionOption. This might be what you were looking for. If instead you wanted a way to override any component, then we should wait for the more generic solution suggested in the above comment:2 (which I think this ticket should be dedicated to, hence the 1.0).

[Christian Boos]

Milestone 1.0 deleted

[Ryan J Ollos]

The proposed patch has been voted down and the alternate proposed solution is vague, so closing this ticket.