[SalesForce] Get VisualForce Email Template as Blob

I don't think you can do it with pure email template, you'll need some Apex, as suggested in other answers.

<messaging:emailTemplate> complains as soon as you'd try to stick <apex:repeat> in there (for example to create <messaging:attachment> nodes in a loop).

Even if you could - try referring to {!relatedTo.Attachments[0].Body} somewhere (can be in the plaintextBody tag), you'll get an error:

Binary fields cannot be selected in join queries

I think the closest it can get is to create the links to attachments (and if I recall correctly - SF converts attachments > 3 MB to links anyway).

<messaging:emailTemplate subject="hello" recipientType="Contact" relatedToType="Opportunity">
<messaging:htmlEmailBody >
    <p>This will list link to attachments... it's not a perfect solution but it's something.</p>

    <apex:repeat value="{!relatedTo.Attachments}" var="a">
    <p><a href="{!URLFOR($Action.Attachment.Download, a)}">{!a.Name}</a> ({!a.BodyLength} B)</p>
    </apex:repeat>
</messaging:htmlEmailBody>
<messaging:plainTextEmailBody >
    <apex:repeat value="{!relatedTo.Attachments}" var="a">
        {!a.Name} {!a.ContentType} {!a.Body} <!-- this "Body" reference causes the compilation to fail -->
    </apex:repeat>
</messaging:plainTextEmailBody>

<!--
<messaging:attachment filename="{!relatedTo.Attachments[0].Name}" renderAs="{!relatedTo.Attachments[0].ContentType}">
 {!relatedTo.Attachments[0].Body}  :(
</messaging:attachment>
-->
</messaging:emailTemplate>

OK, this could be the issue (having recently faced this myself)

Your database structure appears to be:

• License__c
• Several License_Property__c each of which has a lookup relationship to License__c

You mentioned that you are using a workflow to fire the email alert that references the License__c. The target of the workflow, is represented in the VF email template by relatedTo.id

• Per VF order of execution, relatedTo.id is passed as an attribute to the custom component and assigned to the custom controller's m_licenseId via the setId() method
• The order of execution now has the component calling getLines() that calls Initialize() to fetch the list of License_property__c

So far, so good.

My hypothesis, and where I was bitten, is when you test the template in the VF Email Template editor, you already had built the License__c and related License_Property__cs. The template renders fine

But when you test via exercising the workflow, no License_property__cs appear

A likely cause of this is that the workflow is triggered too soon - before the License_Property__c are built by whatever process causes the workflow on License__c to fire. Check your workflow entry criteria versus the state of the database.