ios - Selectively push in viewWillAppear in a UIViewControllerContainer -

we have app model object can pass through various states in progressive fashion - think of order progressing sale, example. each state of order handled different view controller.

each view controller recognizes state(s) can handle, , when state has been reached cannot handle, pushes subsequent view controller handle next state. various events can cause vc update view; method setupviewbyorderstate called @ point. same method called in viewdidappear.

for example, order can pass through states 1-10. viewcontroller handles states 1-2, b handles 3-5, , c handles 6-10.

if handed order in state 1 or 2, configures itself. if handed order in state 3 or greater, pushes b, , hands off order. etc.

one advantage of technique first vc 'entry point' - hand given order , push necessary vcs until 1 reached can handle order in current state, without logic explicitly coding state->vc correspondences ever needing exist outside each vc.

a problem arises, though, should 1 wish pop backward through view stack or dismiss modals. c popped, viewdidappear of b called, puts on (to handle order in state) -- puts c on.

what's appropriate pattern dealing this?

checking isbeingpresented doesn't work. these view controllers in custom uiviewcontrollercontainer, well. flag read-only, knowledge how gets set great.

just don't use viewdidappear that. when create "next" view controller, create , call view controller specific initialization method handle have been handling in viewdidappear.

you want decouple view appearance order state.