Tag Archives: Trigger

Handle Trigger and Validation Rule Error in Lightning Component

Sometimes we can have a requirement to display validation rule error or apex trigger error messages, on save of record in Lightning Component. We can handle those errors from apex controller and can throw messages to Lightning Component. In lightning response object though the state value comes as ERROR but the message in the error object always says ‘Internal Server Error”. Here is an example to handle the Trigger and Validation Rule Error in apex controller to show error messages in Lightning Component.

In below example I’ve used Lead object FirstName, LastName, Email & Company Field in lightning component to create record. And I’ve created a validation rule and a trigger validation on Lead object.

1. Validation rule for Company field (Company cannot be Test Company).

2. In below Trigger I’m checking if FirstName field value is “Test” then it will throw error.

trigger LeadTrigger on Lead (before insert, before update) {
    for(Lead obj :Trigger.new){
        if(obj.FirstName == 'Test'){
            obj.FirstName.addError('First name cannot be test');

Apex Controller:

public class SampleAuraController {
    Public static void createLead(Lead objLead){
        String msg = '';
            //Insert Lead Record
            insert objLead; 
        }catch(DmlException e){
            //Any type of Validation Rule error message, Required field missing error message, Trigger error message etc..
            //we can get from DmlException
            //Get All DML Messages
            for (Integer i = 0; i < e.getNumDml(); i++) {
                //Get Validation Rule & Trigger Error Messages
                msg =+ e.getDmlMessage(i) +  '\n' ;
            //throw DML exception message
            throw new AuraHandledException(msg);
        }catch(Exception e){
            //throw all other exception message
            throw new AuraHandledException(e.getMessage());
        finally {

Lightning Component:

<aura:component controller="SampleAuraController" implements="flexipage:availableForAllPageTypes,force:appHostable">
    <!--Declare Attributes-->
    <aura:attribute name="isSpinner" type="boolean" default="false"/>
    <aura:attribute name="objLead" type="Lead" default="{'sobjectType':'Lead', 
                                                        'FirstName': '',
                                                        'LastName': '',
                                                        'Email': '', 
                                                        'Company': ''}"/>
    <!--Component Start--> 
    <div class="slds-m-around--xx-large">
        <div class="container-fluid">
            <div class="form-group">
                <lightning:input name="fname" type="text" maxlength="50" required="true" label="First Name" value="{!v.objLead.FirstName}" />
            <div class="form-group">
                <lightning:input name="lname" type="text" maxlength="50" required="true" label="Last Name" value="{!v.objLead.LastName}" />
            <div class="form-group">
                <lightning:input name="emailId" type="email" maxlength="100" required="true" label="Email" value="{!v.objLead.Email}" />
            <div class="form-group">
                <lightning:input name="company" type="text" maxlength="50" required="true" label="Company" value="{!v.objLead.Company}" />
        <lightning:button variant="brand" label="Submit" onclick="{!c.handleLeadSave}" />        
        <lightning:button label="Cancel" onclick="{!c.handleCancel}"/>        
    <!--Component End-->

Lightning JS Controller:

    //Handle Lead Save
    handleLeadSave : function(component, event, helper) {
        var objLead = component.get("v.objLead");
        var action = component.get("c.createLead");
            objLead : objLead
            var state = a.getState();
            if(state === "SUCCESS"){
                alert('Record is Created Successfully');
            } else if(state === "ERROR"){
                var errors = action.getError();
                if (errors) {
                    if (errors[0] && errors[0].message) {
            }else if (status === "INCOMPLETE") {
                alert('No response from server or client is offline.');


Trigger Error Message:

Validation Rule Error Message:

Restrict multiple approval for a single user to a single record in Salesforce

I had a requirement to restrict multiple approval for a single user to a single record. There were multiple steps of approval process and the approver may be in different queue or as a manager for a user.

So, I implemented it using a trigger. In this article I’ll demonstrate how to implement it.
Here Application__c is the object, on which 3 steps approval process has implemented.
A custom check box field Check_Approver__c has set value to true, in all 3 steps field update action.

In below trigger I filtered the ProcessInstanceStep object records with current user Id in ActorId and the object Id (here object Id means record Id) in ProcessInstance.TargetObjectId.

  • If an User will approve or reject a record, then the SOQL query will return a single record.
  • If the SOQL query return a record, then trigger will throw an error message.

Trigger source code:

trigger ApplicationTrigger on Application__c (before Update)

        Id currentUserId = UserInfo.getUserId();
        for(Application__c sf: trigger.new){   
            if(sf.Check_Approver__c == true){
                List<processinstancestep> existingApprovals = [SELECT ActorId
                                    FROM ProcessInstanceStep WHERE ProcessInstance.TargetObjectId = :sf.Id
                                    AND (StepStatus = 'Approved' OR StepStatus = 'Rejected')
                                    AND ActorId = :currentUserId];
                if(existingApprovals != null){
                    if(existingApprovals.size() > 0){

                        sf.addError('You have already approved or rejeted the record.');

Difference between trigger and workflow rule

Workflow Rules:

  • Workflow is an automated process that fired after an action, based on evaluation criteria and rule criteria.
  • Workflow actions are Field Update, Email alert, Task alert and outbound message.
  • Workflow will be helpful to update the same object or master object in custom master-detail relationships.
  • We cannot fire workflows after record has been deleted.
  • We cannot query from database on workflow.


  • Trigger is a piece of code that executes before or after, when an DML event occurs like insert, update or Delete.
  • Trigger executes before or after these types of operations insert, update, delete, merge, upsert & undelete.
  • We can access the trigger across the object and related to that objects.
  • We can use DML operations in one trigger.
  • We can use SOQL’s from data base in one trigger.