Dynamic Field required and error message in Salesforce Lightning Web Component

Dynamic Field required and error message in Salesforce Lightning Web Component

setCustomValidity() and reportValidity() methods can be used for dynamic Field required and error message in Salesforce Lightning Web Component.

Sample Code:

HTML:

<template>
    <div class="slds-theme--default slds-p-around_large">
        <lightning-input 
            type="toggle" 
            label="Basic option" 
            name="toggle" 
            onchange={onHandleValueChange}>
        </lightning-input><br/><br/>
        <lightning-input 
            type="text" 
            label="Enter some text" 
            name="text" 
            required={requiredBool}  
            class="inputText">
        </lightning-input>
    </div>  
</template>

JavaScript:

import { LightningElement } from "lwc";

export default class sampleLightningWebComponent extends LightningElement {

    requiredBool = false;

    onHandleValueChange( event ) {

        let selectedValue = event.detail.checked;
        console.log( 
            "Event is",
            JSON.stringify( 
                event.detail 
            ) 
        );
        console.log( 
            "Selected Value is",
            selectedValue 
        );
        let inputText = this.template.querySelector( 
            ".inputText" 
        );

        if ( selectedValue === true ) {

            this.requiredBool = true;

            if ( !inputText.value ) {
                
                inputText.setCustomValidity( 
                    "This field is required/mandatory" 
                );
                inputText.reportValidity();

            }

        }
        else {

            let tempBool = false;

            if ( !inputText.value ) {
                /* Setting value to Temp to avoid 
                Value Missing error message */
                inputText.value = "Temp";
                tempBool = true;
            }

            inputText.setCustomValidity( '' );
            inputText.reportValidity();
            this.requiredBool = false;

            if ( tempBool ) {

                inputText.value = undefined;

            }

        }

    }

}

js-meta.xml:

<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>58.0</apiVersion>
    <isExposed>true</isExposed>
    <targets>
        <target>lightning__Tab</target>
    </targets>
</LightningComponentBundle>

Output:

Dynamic Field required and error me...
Dynamic Field required and error message in Salesforce Lightning Web Component

Leave a Reply