Lightning Aura Components Developer Guide

Introducing Aura Components
Quick Start
Creating Components
Using Components
Communicating with Events
Actions and Events
Handling Events with Client-Side Controllers
Component Events
Application Events
Event Handler Behavior for Active Components
Event Handling Lifecycle
Advanced Events Example
Firing Events from Non-Aura Code
Events Best Practices
Events Anti-Patterns
Events Fired During the Rendering Lifecycle
Events Handled in the Salesforce Mobile App and Lightning Experience
System Events
Communicating Across the DOM with Lightning Message Service
Creating Apps
Styling Apps
Developing Secure Code
Using JavaScript
Working with Salesforce Data
Testing Components
Debugging
Performance
Reference
PDF

Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Events Anti-Patterns

These are some anti-patterns that you should avoid when using events.

Don't Fire an Event in a Renderer

Firing an event in a renderer can cause an infinite rendering loop.

Don’t do this!

1afterRender: function(cmp, helper) {
2    this.superAfterRender();
3    $A.get("e.myns:mycmp").fire();
4}

Instead, use the init hook to run a controller action after component construction but before rendering. Add this code to your component:

1<aura:handler name="init" value="{!this}" action="{!c.doInit}"/>

For more details, see .Invoking Actions on Component Initialization.

Don’t Use onclick and ontouchend Events

You can’t use different actions for onclick and ontouchend events in a component. The framework translates touch-tap events into clicks and activates any onclick handlers that are present.