event hijacking - flash gaia framework

gaia event hijacking 可是相當博大精深的呀~~
首先要知道有哪些 gaia flow events 可用
beforeGoto
afterGoto
beforeTransitionOut
afterTransitionOut
beforePreload
afterPreload
beforeTransitionIn
afterTransitionIn
afterComplete(no hijacking)

假設要在 transitionIn 之前做一些事，
先宣告
private var releaseGaia:Function;
// in constructor
releaseGaia = Gaia.api.beforeTransitionIn(onBeforeTransitionIn,true);

private function onBeforeTransitionIn(event:GaiaEvent):void {
  // do something...
  releaseGaia();
}

另外在 Navigation 裡常用的手法，
// in init
Gaia.api.afterGoto(setPageId, false, false);

private function setPageId(e:GaiaEvent):void {
  trace(e.validBranch);
}

用來做 breadcrumb  還蠻方便的。

[ref]
http://www.gaiaflashframework.com/wiki/index.php?title=Events_and_Hijacking