Lightning Aura Components Developer Guide

Introducing Aura Components
Quick Start
Creating Components
Using Components
Communicating with 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
Lightning Component Library
System Tag Reference
aura:application
aura:dependency
aura:event
aura:interface
aura:method
aura:set
JavaScript API
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.

aura:method

Use <aura:method> to define a method as part of a component's API. This enables you to directly call a method in a component’s client-side controller instead of firing and handling a component event. Using <aura:method> simplifies the code needed for a parent component to call a method on a child component that it contains.

The <aura:method> tag has these system attributes.

Attribute Type Description
name String The method name. Use the method name to call the method in JavaScript code. For example:
1cmp.sampleMethod(param1);
action Expression The client-side controller action to execute. For example:
1action="{!c.sampleAction}"

sampleAction is an action in the client-side controller. If you don’t specify an action value, the controller action defaults to the value of the method name.
access String The access control for the method. Valid values are:
  • public—Any component in the same namespace can call the method. This is the default access level.
  • global—Any component in any namespace can call the method.
description String The method description.

Declaring Parameters

An <aura:method> can optionally include parameters. Use an <aura:attribute> tag within an <aura:method> to declare a parameter for the method. For example:

1<aura:method name="sampleMethod" action="{!c.doAction}" 
2  description="Sample method with parameters"> 
3    <aura:attribute name="param1" type="String" default="parameter 1"/> 
4    <aura:attribute name="param2" type="Object" /> 
5</aura:method>

For more information, see the Returning a Value section below.

You don’t need an access system attribute in the <aura:attribute> tag for a parameter.

Note

Creating a Handler Action

This handler action shows how to access the arguments passed to the method.

1({
2    doAction : function(cmp, event) {
3        var params = event.getParam('arguments');
4        if (params) {
5            var param1 = params.param1;
6            // add your code here
7        }
8    }
9})

Retrieve the arguments using event.getParam('arguments'). It returns an object if there are arguments or an empty array if there are no arguments.

Returning a Value

aura:method executes synchronously.

  • A synchronous method finishes executing before it returns. Use the return statement to return a value from synchronous JavaScript code. See Return Result for Synchronous Code.
  • An asynchronous method may continue to execute after it returns. Use a callback to return a value from asynchronous JavaScript code. See Return Result for Asynchronous Code.