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Broadcasting and Event Handling with $broadcast and $on in Angular
Understanding the Problem
Angular's event handling is a fundamental aspect of communication between components. This particular scenario involves triggering an event in a footer component and handling it within a code scanner component. The question explores how to achieve this using $broadcast and $on.
Using $broadcast for Event Emitting
In the footer component's controller, the $rootScope can be utilized for event broadcasting:
<code class="javascript">$scope.startScanner = function() { $rootScope.$broadcast('scanner-started'); }</code>
This line emits an event named 'scanner-started' when the button in the footer is clicked.
Using $on for Event Listening
In the code scanner component's controller, the $scope can be used to listen for the broadcasted event:
<code class="javascript">$scope.$on('scanner-started', function(event, args) { // Handle event });</code>
This event listener will be triggered whenever the 'scanner-started' event is emitted.
Passing Arguments with $broadcast
Arguments can be passed along with the broadcasted event using the $broadcast method:
<code class="javascript">$rootScope.$broadcast('scanner-started', { any: {} });</code>
Retrieving Arguments in $on
The passed arguments can be retrieved in the $on event listener:
<code class="javascript">$scope.$on('scanner-started', function(event, args) { var anyThing = args.any; // Handle event });</code>
Additional Considerations
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