I'm building a method for my client to construct a message content to be sent with wp_mail. Within that I'd like them to be able to choose variables, for example the message might look like this in my admin custom field:
First Name: $first_name$
So that when I iterate over the lines I can spot a variable place-holder and replace $email_address$ with my variable so my PHP would look like:
$body = 'Email Address: email@example.com<br>First Name: Mickey Mouse'; wp_mail( $to, $subject, $body, $headers );
I suppose I'm wondering if there's a particular or PHP-ish way to do this, I'm sure I've seen it in plugins before but don't recall the exact formatting.