Set parameter in email?

Question

Regarding a VisualForce email template, I know it is possible to setWhatId(), setSubject() and range of other things in Messaging.SingleEmailMessage. But I just want to set my own parameter.

Let me expand on what I mean by my own parameter. I want to be able to use a parameter in a URL I use in img tag.

<img id="toplogo" src="{!$MyParameter}" height="20"/>

I am merging a custom object into the email. So I could always add a parameter to this custom object and merge that way. But is there anyway I can do it without going near my custom object?

Answer 1

I don't totally understand what you are trying to do, but if you are trying to add a querystring parameter, that's pretty easy...

<img id="toplogo" src="http://myurl.com/image.png?myparam={!$myParameter}" height="20"/>

Just make sure that your parameter is URL encoded. If you are leveraging Visualforce Components in your Visualforce Email template, you could do that in your controller like so...

public class MyEmailController {
  public String getMyParameter() {
    EncodingUtil.urlEncode('parameter that needs encoding');
  }
}

And the component...

<apex:component controller="MyEmailController" access="global">
  <img id="toplogo" src="http://myurl.com/image.png?myparam={!$myParameter}" height="20"/>
</apex:component>

Here are the docs that might help