Email content not rendering when Pass custom relatedTo object's param from visual force email template to controller

Question

I'm really confused by order of execution. I have tried with a few posts, but mine does not work. Please help with taking a look.

I am able to receive the templated email, but there's no incident fields contents rendered in the email. The received email shows the No incidents to report. If I set Test with merge fields, and provide static environment Id and contactId, then it works and show the binded incidents in the received email. The environmentId seems not passed into the template/controller.

The ultimate goal is to trigger email firing by scheduled apex job. In testing phase, I'm using following code to run, and can receive fired email. But the email content is No incidents to report.

SenderForIncidents sender = new SenderForIncidents();
sender.execute(null);

public with sharing class SenderForIncidents Implements Schedulable{
    public void execute(SchedulableContext sc){
        // Queries prepared template, orgWideEmail, and contactList
        EmailTemplate template = [SELECT Id FROM EmailTemplate WHERE... LIMIT 1];
        OrgWideEmailAddress orgWideEmail = [SELECT Id FROM OrgWideEmailAddress WHERE ... LIMIT 1];
        List<Contact> contactList = [SELECT ......];

        List<Messaging.SingleEmailMessage> emailSendList = new List<Messaging.SingleEmailMessage>();
        for (Contact c : contactList){
            Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();
            email.setOrgWideEmailAddressId(orgWideEmail.Id);
            email.setTemplateId(template.Id);
            email.setTargetObjectId(c.Id);
            email.saveAsActivity = false;
            email.setWhatId(relatedToTypeObjectId); UPDATE-------> SOLUTION!!!!!!
            emailSendList.add(email);
        }
        Messaging.sendEmail(emailSendList, false);
    }
}

============ Below are email template, VF component, and controller info.===============

Email template

<messaging:emailTemplate subject="{!relatedTo.Name}" 
                         recipientType="Contact" 
                         relatedToType="Environment__c">
     <c:MyController environmentId="{!relatedTo.Id}" />
</messaging:emailTemplate>

Visual force component

<apex:component controller="MyController" access="global">
    <apex:attribute name="environmentId" type="Id" 
                   description="Environment Id" assignTo="{!envId}" />
    <apex:outputPanel rendered="{!!incidents.empty}">
        <apex:repeat value="{!incidents}" var="incident">
             <p>{!incident.fieldA__c}</p>
    </apex:outputPanel>
    <apex:outputPanel rendered="{!incidents.empty}">
        <p> No Incidents to Report. </p>
    </apex:outputPanel>
</apex:component>

controller

Suggested controller version from first answer.
public class MyController() {
    public Id envId;
    public void setEnvId(Id envIdValue) {
        List<Object2> matchedObj2 = [SELECT Case__c FROM Object2 where Environment__c = :envId];
            List<Id> caseIds = new List<Id>();
            for (Object2 obj : matchedObj2) {
                caseIds.add(obj.Case__c);
            }

            incidents = [SELECT ... FROM Case WHERE Id in :caseIds ];
    }

    public MyController(){}
    public List<Case> incidents {get; set;}   
}

My original version
/*public class MyController {
    public Id envId {get; set;}

    public MyController(){}

    public List<Case> incidents;
    public List<Case> getIncidents() {
        if (incidents == null) {
            List<Object2> matchedObj2 = [SELECT Case__c FROM Object2 where Environment__c = :envId];

            List<Id> caseIds = new List<Id>();
            for (Object2 obj : matchedObj2) {
                caseIds.add(obj.Case__c);
            }
            incidents = [SELECT .... FROM Case WHERE Id in :caseIds AND ...];
        }

        return incidents;
    }
}*/

I have tried to test with merge field in email template with EnvironmentId and contact, it works. Seems either the template is not associating to environment__c, or the value was not passed to the controller. Generous help appreciated. Thank you.

Answer 1

public class MyController {
    public Id envId {get; set;}

    public MyController(){}

    public List<Case> incidents {
        get {
           if (incidents == null) {

             incidents = new List<Case> ();
             if (this.envId != null) {
               Object2[] matchedObj2 = [SELECT Case__c FROM Object2 where Environment__c = :this.envId];

               List<Id> caseIds = new List<Id>();
               for (Object2 obj : matchedObj2) {
                 caseIds.add(obj.Case__c);
               }
               incidents = [SELECT .... FROM Case WHERE Id in :caseIds AND ...];
             }
           }

           return incidents;
       } private set;
  }

This should work (albeit untested). I've never used the .empty for VF collection size testing although I see others have shown this to work. I prefer a getter method hasIncidents in a controller that tests for empty collection or can be extended for special cases.

Update

You posted the schedulable class's execute and the relevant section is here:

Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();
        email.setOrgWideEmailAddressId(orgWideEmail.Id);
        email.setTemplateId(template.Id);
        email.setTargetObjectId(c.Id);
        email.saveAsActivity = false;
        emailSendList.add(email);

Since your email template has a relatedToType="Environment__c", you need to tell from Apex an ID pointing to a single Environment__c. This is done with the setWhatId(..) method

Answer 2

Your problem is using a getter to load the data, plus a lazy load pattern. Because getters can be called several times in a transaction, you should avoid this design.

Instead, use a setter:

public void setEnvId(Id value) {
  loadIncidenceList(value);
}
public case[] incidents { get; set; }
void loadIncidenceList(Id envId) {
  // your original logic here //
}