Display child trigger error in friendly way on parent record page

Question

Example

When updating an Account record, it fires an Account before update trigger which changes a child Contact record, which fires a Contact before update trigger, which validates the change and rejects it using addError.

But the error message is displayed as a unfriendly error message on the Account page.

Similar to the below:

Question

How can I display the child record error message in a friendly way to the user on the parent record page?

Answer 1

One of the approaches could be to listen for errors which are happening in your main object trigger on DML statement, and in case if there are any -- do addError on corresponding parent record.

For example, let's assume the following trigger code, used to update contact last name based on account name:

trigger tr_Account on Account (after update) {
    List<Contact> child_contacts = 
             [SELECT Id, LastName 
             FROM Contact 
             WHERE AccountId in :(List<Account>) Trigger.new];
    Map<Id, List<Contact>> contacts_by_account = new Map<Id, List<Contact>>();
    for(Contact c : child_contacts) {
        if (!contacts_by_account.containsKey(c.AccountId)) {
            contacts_by_account.put(c.AccountId, new List<Contact>());
        }
        contacts_by_account.get(c.AccountId).add(c);
    }
    List<Contact> contacts_to_update = new List<Contact>();
    for(Account a : (List<Account>) Trigger.new) {
        List<Contact> contacts_to_process = contacts_by_account.get(a.Id);
        if (contacts_to_process != null) {
            for(Contact c : contacts_to_process) {
                if (c.LastName != a.Name) {
                    c.LastName = a.Name;
                    contacts_to_update.add(c);
                }
            }
        }
    }
    update contacts_to_update;
}

In the given scenario, if there is an error on the last line (update contacts_to_update), it will stop entire transaction in order since that will be treated as Exception. Exactly that kind of message is visible in your screenshot. In order to ensure that your DML does not throw an exception, explicit Database.update(list,all_or_none); method might be used. Consider following example as instead of update contacts_to_update;:

Integer counter = 0;
List<Database.SaveResult> results = Database.update(contacts_to_update, true);//or false in order to support partial DML nicely
for(Database.SaveResult sr : results) {
    if (!sr.isSuccess()) {
        //Take only first error for demo purpose
        String error_message = 'Issue with Contact Update: ' 
             + sr.getErrors().get(0).getMessage();
        Id account_id = contacts_to_update.get(i).AccountId;
        trigger.newMap.get(account_id).addError(error_message);
    }
}

Given code will try to update child contacts first, and in case if there are any kind of errors -- it will collect them and discard corresponding parent account with controlled error.

Answer 2

If you write addError on Contact then the current contex does not idetify To display the error on Account you must have to write add error code on your account trigger.

trigger validateError on Account (before insert)
{
    for(Account acc : trigger.new)
    {
        // your logic to check valida account 
        acc.addError('Show error on Account'); 
        //acc.MyFields__c.addError('Show error on Account fields');
    }
}