execution of AfterInsert caused by: System.FinalException: Record is read-only: Trigger.AppLeadCreation: line 68

Question

I have written an trigger for update application object based on new created record. In update logic its working but I am getting error on insert logic.

Apex trigger AppLeadCreation caused an unexpected exception, contact your administrator: AppLeadCreation: execution of AfterInsert caused by: System.FinalException: Record is read-only: Trigger.AppLeadCreation: line 68, column 1

Please check the below code and suggest me what's wrong with this?

trigger AppLeadCreation on alu_Application__c (after insert,before update){

    // SOQL QUERY FOR ITERATES
    private static List<Lead> leadsList= new List<Lead>();
    private static Set<String> appEmails = new Set<String>();


    // MAP OF IDs AND EMAIL ADDRESS OF LEAD
    private static  Map<String,Id> mapIdsWithLeadEmail = new Map<String,Id>();

    // MAP OF IDs AND EMAIL ADDRESS OF APPLICATION
    Map<Id,String> mapIdsWithAppEmail = new Map<Id,String>();

    // MAP OF LEAD IDs AND APPLICATION ID
    Map<Id,Id> mapAppIdsEmailIds = new Map<Id,Id>();

    Map<Id,Lead> mapAppIdwithLeads = new Map<Id,Lead>();

    Map<Id,Lead> leadsToCreate = new Map<Id,Lead>();

    Map<Id,Lead> leadtoUpdate = new Map<Id,Lead>();     

    Map<Id,alu_Application__c> apptoUpdate = new Map<Id,alu_Application__c>(); 
   // to prevent the recursion  
    public static boolean isRecursive=true;
    System.debug('mapIdsWithLeadEmail'+mapIdsWithLeadEmail);

    for(alu_Application__c app : trigger.new){
        if(String.isNotBlank(app.Email__c)){
           mapIdsWithAppEmail.put(app.Id,app.Email__c);
           appEmails.add(app.Email__c);
         }
    }
    System.debug('mapIdsWithAppEmail'+mapIdsWithAppEmail);
    try {
           if(!mapIdsWithAppEmail.isEmpty() && isRecursive){
               isRecursive = false;
              // fetch leads information based on Application Email
              leadsList =[SELECT Id, Email FROM Lead WHERE Email IN: appEmails];
              if(!leadsList.isEmpty()){
                 for(Lead le : leadsList){       
                   mapIdsWithLeadEmail.put(le.email, le.Id);
              }
             } 

            for(Id tmp : mapIdsWithAppEmail.KeySet()){
                String appEmail = mapIdsWithAppEmail.get(tmp);
               if(mapIdsWithLeadEmail.ContainsKey(appEmail)){ 
                   mapAppIdsEmailIds.put(tmp,mapIdsWithLeadEmail.get(appEmail));
               }else{
                    leadsToCreate.put(tmp,leadInfo(trigger.newMap.get(tmp),'insert',null));
               }
              }
            }
        System.debug('mapAppIdsEmailIds'+mapAppIdsEmailIds);
        System.debug('leadsToCreate'+leadsToCreate);

        if(!mapAppIdsEmailIds.isEmpty() || !leadsToCreate.isEmpty()){
            //insert the new leads for unmathced application EMAIL
            Database.insert(leadsToCreate.values());

            for(alu_Application__c app : trigger.new){
                if(mapAppIdsEmailIds.ContainsKey(app.Id)){
                    app.Lead__c = mapAppIdsEmailIds.get(app.Id);
                    leadtoUpdate.put(app.Id, leadInfo(app,'update',app.Lead__c));
                }               
                else if(leadsToCreate.containsKey(app.Id)){
                    **app.Lead__c = leadsToCreate.get(app.Id).Id;**
                }
                if(Trigger.isAfter && Trigger.isInsert && app.Lead__c != NULL){
                    apptoUpdate.put(app.Id,app);
                }
            }
            if(!leadtoUpdate.isEmpty()){
                update leadtoUpdate.values();
            }
            if(!apptoUpdate.isEmpty()){
                update apptoUpdate.values();
            }
         }     
        }Catch(Exception e){
        System.debug('ERROR:' + e.getMessage());
        System.debug('ERROR:' + e.getLineNumber());
      }

     private static Lead leadInfo(alu_Application__c app, String eventType, Id LeadId){
         Lead leadtoSend = new Lead();
         if(eventType.equals('update')){
             leadtoSend.Id = LeadId;
         }
         leadtoSend.FirstName = app.First_Name__c;
         leadtoSend.LastName = app.Last_Name__c;
         leadtoSend.Email = app.Email__c;
         leadtoSend.Campus_Preference__c = app.Campus_Preference__c; 
         leadtoSend.Company = app.First_Parent_Company__c;


        return leadtoSend;
     }

}

Answer 1

You can't attempt to modify any fields in a record on Trigger.new. At minimum, it looks like you'll need to change this:

        if(!mapAppIdsEmailIds.isEmpty() || !leadsToCreate.isEmpty()){
            //insert the new leads for unmathced application EMAIL
            Database.insert(leadsToCreate.values());

            for(alu_Application__c record: trigger.new){
                // Temp record to use for update
                alu_Application__c app;
                if(mapAppIdsEmailIds.ContainsKey(record.Id)){
                    if(Trigger.isBefore) {
                        record.Lead__c = mapAppIdsEmailIds.get(record.Id);
                    } else {
                        // Clone record and update
                        app = record.clone(true);
                        app.Lead__c = mapAppIdsEmailIds.get(app.Id);
                    }
                    leadtoUpdate.put(record.Id, leadInfo(record,'update',app.Lead__c));
                }
                else if(leadsToCreate.containsKey(record.Id)){
                    if(Trigger.isBefore) {
                        record.Lead__c = leadsToCreate.get(record.Id).Id;
                    } else {
                        // Clone record and update
                        app = record.clone(true);
                        app.Lead__c = leadsToCreate.get(record.Id).Id;
                    }
                }
                if(app != null) {
                    appToUpdate.put(app.Id, app);
                }
            }
            update leadtoUpdate.values();
            update apptoUpdate.values();
         }

You could probably optimize your code some more (I took out some extraneous "if" statements, for example).