sending an email from an with an apex trigger with the recipient email from a custom field

Question

I am trying to create an apex email trigger on an Opportunity but have the recipient email come from a custom field called Agent email. I would like the email to be sent when the Stage is in Agent Accepted. I just started writing tiggers and I am not sure how to get the code to work. I have found a few posts about the email trigger but I am very confused.

Thank you for any suggestions.

trigger AgentEmailfee on Opportunity  (after Insert,after update) {
                  EmailTemplate template = [SELECT Id, Subject, HtmlValue, Body FROM EmailTemplate 
                                            WHERE Name = 'Agent_Referral_Fee'];
//Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
  //           mail.setTemplateId(template.id);


                          String subject = template.Subject;
subject = subject.replace('{!Opportunity.Name}','has been accepted'); 

 // Pick ca dummy Contact
 Opportunity o =[select id, Email from Contact where email <> null limit 1];

 // Construct the list of emails we want to send
 List <Messaging.SingleEmailMessage> lstMsgs = new List<Messaging.SingleEmailMessage>();

 Messaging.SingleEmailMessage msg = new Messaging.SingleEmailMessage();
 msg.setTemplateId( [select id from EmailTemplate where DeveloperName='Agent_Referral_Fee'].id );
 msg.setWhatId( [select id from Opportunity limit 1].id );
 msg.setTargetObjectId(o.agent_email__c);
 msg.setToAddresses(new List<String>{''});

 lstMsgs.add(msg);

 // Send the emails in a transaction, then roll it back
 Savepoint sp = Database.setSavepoint();
 Messaging.sendEmail(lstMsgs);
 Database.rollback(sp);

 // For each SingleEmailMessage that was just populated by the sendEmail() method, copy its
 // contents to a new SingleEmailMessage. Then send those new messages.
 List<Messaging.SingleEmailMessage> lstMsgsToSend = new List<Messaging.SingleEmailMessage>();
 for (Messaging.SingleEmailMessage email : lstMsgs) {
 Messaging.SingleEmailMessage emailToSend = new Messaging.SingleEmailMessage();
 emailToSend.setToAddresses(email.getToAddresses());
 emailToSend.setPlainTextBody(email.getPlainTextBody());
 emailToSend.setHTMLBody(email.getHTMLBody());
 emailToSend.setSubject(email.getSubject());
 lstMsgsToSend.add(emailToSend);
 }
 Messaging.sendEmail(lstMsgsToSend);

    }
 for (opportunity o :Trigger.new)
    {
        if(o.Agent_Assigned__c != NULL)
            (o.Referral_Fee__c = TRUE);
            (o.stageName ='Agent Assigned'); 

Answer 1

I found out I did not need a trigger. I can use a workflow rule You can as long as the Agent Email is of type: Email. Here is how you can do that: 1. Setup | Create | Workflows & Approvals | Workflow Rules 2. New Rule 3. Select the Object: Opportunity 4. Evaluation Criteria: created and every time it's edited to subsequently meet the criteria 5. Rule Criteria: criteria are met 6. Criteria:
7.
Stage equals Agent Accepted 8. Click Save & Next 9. From under Immediate Workflow Actions, click Add Workflow Action select Email Alert 10. Specify the Email Template 11. Select the Recepient as Email Field 12. Select the Agent Email 13. Click Save 14. Hit Done 15. Activate