Contact Trigger Template

^{Use only one trigger per SObject Type}

Multiple triggers on the same object are not recommended because Salesforce cannot guarantee the order of execution, so we should only add one trigger per object.

So, let’s look at the Contact Trigger Template and see how we can use one trigger per object.

Trigger Handler Interface

An interface is similar to a class in which none of the methods have been implemented—the method signatures are present, but the method bodies are empty. To use an interface, another class must implement it by providing a body for all of the interface’s methods.

Interfaces can help your code by adding a layer of abstraction. They separate the specific implementation of a method from its declaration. This way, depending on your application, you can have different implementations of a method.

There should be only one TriggerHandler Interface in the entire org, not one for each object.

	public interface TriggerHandler {

	// ******** before methods *****************
	void beforeInsert(List<SObject> newRecords);
	void beforeUpdate(List<SObject> newRecords, List<SObject> oldRecords,
	Map<Id,SObject> newRecordMap,Map<Id,SObject> oldRecordMap);
	void beforeDelete(List<SObject> oldRecords, Map<Id,SObject> oldRecordMap);

	// ********* after methods ******************
	void afterInsert(List<SObject> newRecords, Map<Id,SObject> newRecordMap);
	void afterUpdate(List<SObject> newRecords, List<SObject> oldRecords,
	Map<Id,SObject> newRecordMap, Map<Id,SObject> oldRecordMap);
	void afterDelete(List<SObject> oldRecords, Map<Id, SObject> oldRecordMap);
	void afterUndelete(List<SObject> newRecords, Map<Id,SObject> newRecordMap);

	}

view raw TriggerHandler.cls hosted with ❤ by GitHub

Contact Trigger

	/**
	* @description ContactTrigger.
	* @Created By: Arun Kumar
	* @Created Date : 26-06-2022
	* @Last Modified Date : 26-06-2022
	*/
	trigger ContactTrigger on Contact (before insert,before update, before delete, after insert,
	after update, after delete,after undelete) {

	TriggerHandler handler = new ContactTriggerHandler(Trigger.isExecuting, Trigger.size);

	switch on Trigger.operationType {
	when BEFORE_INSERT {
	//call before insert handler method
	handler.beforeInsert(Trigger.new);
	}
	when BEFORE_UPDATE {
	//call before update handler method
	handler.beforeUpdate(Trigger.new, Trigger.old, Trigger.newMap, Trigger.oldMap);
	}
	when BEFORE_DELETE{
	//call before delete handler method
	handler.beforeDelete(Trigger.old, Trigger.oldMap);
	}
	when AFTER_INSERT{
	//call after insert handler method
	handler.afterInsert(Trigger.new,Trigger.newMap);
	}
	when AFTER_UPDATE{
	//call after update handler method
	handler.afterUpdate(Trigger.new, Trigger.old, Trigger.newMap, Trigger.oldMap);
	}
	when AFTER_DELETE{
	//call after delete handler method
	handler.afterDelete(trigger.old, Trigger.oldMap);
	}
	when AFTER_UNDELETE{
	//call after undelete handler method
	handler.afterUndelete(trigger.new, Trigger.newMap);
	}
	}

	}

view raw ContactTrigger.trigger hosted with ❤ by GitHub

Contact Trigger Handler

	public without sharing class ContactTriggerHandler implements TriggerHandler{

	private boolean triggerIsExecuting;
	private integer triggerSize;
	public ContactTriggerHelper helper;
	public ContactTriggerHandler(Boolean triggerIsExecuting, integer triggerSize) {
	this.triggerIsExecuting = triggerIsExecuting;
	this.triggerSize = triggerSize;

	this.helper = new ContactTriggerHelper();
	}

	public void beforeInsert(List<Contact> newContacts){
	//call ContactTriggerHandler methods
	helper.updateContactAddresses(newContacts);
	}
	public void beforeUpdate(List<Contact> newContacts, List<Contact> oldContacts, Map<Id,sObject> newContactMap, Map<Id,sObject> oldContactMap){
	//call ContactTriggerHandler methods
	}

	public void beforeDelete(List<Contact> oldContacts, Map<Id,SObject> oldContactMap){
	//call ContactTriggerHandler methods
	}

	public void afterInsert(List<Contact> newContacts, Map<Id,SObject> newContactMap){
	//call ContactTriggerHandler methods

	}
	public void afterUpdate(List<Contact> newContacts, List<Contact> oldContacts, Map<Id,SObject> newContactMap, Map<Id,SObject> oldContactMap){
	//call ContactTriggerHandler methods
	}

	public void afterDelete(List<Contact> oldContacts, Map<Id,SObject> oldContactMap){
	//call ContactTriggerHandler methods
	}

	public void afterUndelete(List<Contact> newContacts, Map<Id,SObject> newContactMap){
	//call AccountTriggerHelper methods
	}
	}

view raw ContactTriggerHandler.cls hosted with ❤ by GitHub

Contact Trigger Helper

	public without sharing class ContactTriggerHelper {
	//Constructor
	public ContactTriggerHelper() {
	system.debug('Inside AccounttriggerHelper Constructor');
	}
	/**
	* @description updateContactsCountOnAccount method counts number of contacts on account records.
	* @param conList
	*/
	public void updateContactsCountOnAccount(List<Contact> conList){
	//write logic to update the account owner
	}
	/**
	* @description updateAddresses method updates contact address
	* copy billing address to contact mailling address
	* @param conList
	*/
	public void updateContactAddresses(List<Contact> conList) {
	//write update contacts logic below
	}
	//Write other methods here as per your requirements

	/****************** ADD MORE METHODS***********************/
	}