// Watch takes a variable number of events to match against. The subscriber
// will receive events that match any of the arguments passed to Watch.
//
// Examples:
//
// // subscribe to all events
// Watch(q)
//
// // subscribe to all UpdateTask events
// Watch(q, EventUpdateTask{})
//
// // subscribe to all task-related events
// Watch(q, EventUpdateTask{}, EventCreateTask{}, EventDeleteTask{})
//
// // subscribe to UpdateTask for node 123
// Watch(q, EventUpdateTask{Task: &api.Task{NodeID: 123},
// Checks: []TaskCheckFunc{TaskCheckNodeID}})
//
// // subscribe to UpdateTask for node 123, as well as CreateTask
// // for node 123 that also has ServiceID set to "abc"
// Watch(q, EventUpdateTask{Task: &api.Task{NodeID: 123},
// Checks: []TaskCheckFunc{TaskCheckNodeID}},
// EventCreateTask{Task: &api.Task{NodeID: 123, ServiceID: "abc"},
// Checks: []TaskCheckFunc{TaskCheckNodeID,
// func(t1, t2 *api.Task) bool {
// return t1.ServiceID == t2.ServiceID
// }}})
func Watch(queue *watch.Queue, specifiers ...Event) (eventq chan events.Event, cancel func()) {
if len(specifiers) == 0 {
return queue.Watch()
}
return queue.CallbackWatch(events.MatcherFunc(func(event events.Event) bool {
for _, s := range specifiers {
if s.matches(event) {
return true
}
}
return false
}))
}
// Watch takes a variable number of events to match against. The subscriber
// will receive events that match any of the arguments passed to Watch.
//
// Examples:
//
// // subscribe to all events
// Watch(q)
//
// // subscribe to all UpdateTask events
// Watch(q, EventUpdateTask{})
//
// // subscribe to all task-related events
// Watch(q, EventUpdateTask{}, EventCreateTask{}, EventDeleteTask{})
//
// // subscribe to UpdateTask for node 123
// Watch(q, EventUpdateTask{Task: &api.Task{NodeID: 123},
// Checks: []TaskCheckFunc{TaskCheckNodeID}})
//
// // subscribe to UpdateTask for node 123, as well as CreateTask
// // for node 123 that also has ServiceID set to "abc"
// Watch(q, EventUpdateTask{Task: &api.Task{NodeID: 123},
// Checks: []TaskCheckFunc{TaskCheckNodeID}},
// EventCreateTask{Task: &api.Task{NodeID: 123, ServiceID: "abc"},
// Checks: []TaskCheckFunc{TaskCheckNodeID,
// func(t1, t2 *api.Task) bool {
// return t1.ServiceID == t2.ServiceID
// }}})
func Watch(queue *watch.Queue, specifiers ...Event) (eventq chan events.Event, cancel func()) {
if len(specifiers) == 0 {
return queue.Watch()
}
return queue.CallbackWatch(Matcher(specifiers...))
}
