javascript - $scope.$on & controller load timing/speeds -

i'm curious timing of when angular controllers loaded versus $scope/event listeners in controllers. could provide documentation or explanation how works?

i've looked while, , not find clear answer on this.

i have example load filter options database, , $emit parent controller, $broadcast event other controllers when occurs. (code abbreviated)

filtercontroller.js

app.controller("filtercontroller", ["$scope", "$q", function($scope, $q) {      (function getinitialfilters() {         $q.all([             // few promises call database information , sets filters         ]).then(function(){             // after promises finish, $emit event parent controller,              // appcontroller             $scope.$emit("heyappcontrollerfiltershaveloaded")           })         }();  }]) 

appcontroller.js (parent controller of filtercontroller , dashboardcontroller)

app.controller("appcontroller", ["$scope", function($scope) {      $scope.$on("heyappcontrollerfiltershaveloaded", function() {         $scope.$broadcast("allchildcontrollersfiltershaveloaded");         console.log('broadcast sent');     }); }]); 

the problem is, when $broadcast occurs, $scope.$on / event listener in child controller misses it, though seems controller has loaded , $emit , $broadcast occurs after longest roundtrip database finishes. (granted, it's not long of trip)

dashboardcontroller.js

app.controller("dashboardcontroller", ["$scope", function($scope) {     console.log('dashboardcontroller loaded');      $scope.$on("allchildcontrollersfiltershaveloaded", function() {         console.log('listener listened');         dosomestuffwithfilters();     }); }]); 

the console prints out in following order:

"dashboardcontroller loaded"

"broadcast sent"

the quick fix solution found here add 500ms timeout $broadcast, , dashboardcontroller catches event.

my question though, controller load, , takes while add $scope.$on / event listener? longer short roundtrip database , longer registering $emit , $broadcast in other controllers? or how timing work here?