A Simple Example of Application Event Handling Between two Custom Lightning Components in Salesforce
Source Page:- w3web.net
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Real time scenarios:- Create an event in Salesforce lightning, and Checked the Value of Checkbox from parent component to child component on click button in Lightning Component using Application event.
Files we used in this post example:-
eventApp1.appLightning ApplicationIt is used for call the component to preview on browser.
eventRegisterCmp1.cmp
Lightning ComponentIt is a parent component and hold a click button.
eventRegisterCmp1Controller.js
JavaScript Controller FileIt is used for click function for Checkbox Checked the Value.eventHandlerCmp1.cmpLightning ComponentIt is a child component of eventRegisterCmp1.cmp, It is hold checkbox input.eventHandlerCmp1Controller.jsJavaScript Controller FileIt is fire automatically and get the value of event from parent component and set value of attribute.repCheckboxEvent.evtLightning EventCreat a application event, hold a boolean type attribute that default value is false.
Live Demo

Step 1:- Create Lightning Application : eventApp1.app
From Developer Console >> File >> New >> Lightning Application
eventApp1.app [Component Application File]
<aura:application extends=”force:slds”>
<c:eventRegisterCmp1/>
</aura:application>
Step 2:- Create Lightning Component : eventRegisterCmp1.cmp
From Developer Console >> File >> New >> Lightning Component
eventRegisterCmp1.cmp [Lightning Component File]
<aura:component >
<aura:registerEvent name=”repCheck” type=”c:repCheckboxEvent”/>
<div class=”slds slds-p-around — medium”>
<button class=”slds-button slds-button — brand” onclick=”{!c.checkVal}”>
checkValue
</button>
<br/><br/>
<c:eventHandlerCmp1/>
</div>
</aura:component>
Step 3:- Create Lightning Component : eventRegisterCmp1Controller.js
From Developer Console >> File >> New >> Lightning Component >> JavaScript Controller
eventRegisterCmp1Controller.js [JavaScript Controller]
({
checkVal : function(component, event, helper) {
var repCheck = $A.get(“e.c:repCheckboxEvent”);
repCheck.setParams({
“selfCheckValue”:true
});
repCheck.fire();
}
})
Step 4:- Create Lightning Component : eventHandlerCmp1.cmp
From Developer Console >> File >> New >> Lightning Component
eventHandlerCmp1.cmp [Lightning Component File]
<aura:component>
<aura:handler event=”c:repCheckboxEvent” action=”{!c.repCheckEnable}”/>
<aura:attribute name=”selfChildDeal” type=”Boolean”/>
<div class=”slds slda-p-around — medium”>
<div class=”slds-form-element__control”>
<label class=”slds-checkbox”>
<ui:inputCheckbox aura:id=”repCheckId” value=”{!v.selfChildDeal}” />
<span class=”slds-checkbox — faux”></span>
<span class=”slds-form-element__label slds-m-left — x-small” style=”font-size: 0.75rem;”>
Self Representative
</span>
</label>
</div>
<br/>
</div>
</aura:component>
Step 5:- Create Lightning Component : eventHandlerCmp1Controller.js
From Developer Console >> File >> New >> Lightning Component >> JavaScript Controller
eventHandlerCmp1Controller.js [JavaScript Controller]
({
repCheckEnable : function(component, event, helper) {
var selfCheckValue1 = event.getParam(“selfCheckValue”);
component.set(“v.selfChildDeal”, selfCheckValue1);
//alert(‘selfCheckValue ‘ + selfCheckValue);
}
})
Step 6:- Lightning Event : repCheckboxEvent.evt
From Developer Console >> File >> New >> Lightning Event
repCheckboxEvent.evt [Lightning Component File]
<aura:event type=”Application” description=”Event template” access=”global”>
<aura:attribute name=”selfCheckValue” type=”Boolean” default=”false”/>
</aura:event>
Source Page:- w3web.net