Salesforce: Iterate Map for old and new Value

 Salesforce: Iterate Map for old and new Value

Trigger

trigger Opportunitytrigger on Opportunity (Before Insert,Before Update,After Update) {


   
        //Before Update 
    if(trigger.isBefore && trigger.isUpdate){
        system.debug('--Before Update');
        Opportunitytriggerhandler oOpportunitytriggerhandler = new Opportunitytriggerhandler();
        oOpportunitytriggerhandler.onBeforeUpdate(Trigger.oldMap,Trigger.newMap);
    }
}

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Handler Class

public class  Opportunitytriggerhandler{
    
    
    public void onAfterUpdate(map<id,Opportunity> oldMap,map<id,Opportunity> newMap){
    
 
    
    public void onBeforeUpdate(map<id,Opportunity> oldMap,map<id,Opportunity> newMap){
        OpportunityHelper objHelper = new OpportunityHelper();
        objHelper.checkOpportunityAmount(oldMap,newMap);
    }
   
}

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Helper Class

public class OpportunityHelper {
    
    public void checkOpportunityAmount(map<id,Opportunity> oldMap,map<id,Opportunity> newMap){
        for(Opportunity opp:newMap.values()){
            //    Needs Analysis  Qualification
            system.debug('Old AMount '+oldMap.get(opp.id).StageName);
            system.debug('New Map'+newMap.get(opp.id).StageName);
            System.debug('Before Update finish');
            if(oldMap.get(opp.id).StageName !=  newMap.get(opp.id).StageName){
                
                opp.isAmountChanged__c = true;
            }

        }
    }

}