This idea is from Classic ASP Master Pages | Godless Code. I’ve transcribed the code in images on that page, extended its example a bit, and also explored the limitations of this technique.
The idea is that each page has only one Server-Side Include (one <!--#include file="" -->
call). The single inclusion is a master template file, which you could name master.asp
. The master page calls custom subroutines on each page in place of each content area. Each child page defines those subroutines with Sub
, with content unique to that child page.
master.asp
<!DOCTYPE html>
<html>
<head>
<title><% Title() %></title>
</head>
<body>
<% BodyContent() %>
</body>
</html>
aboutUs.asp
<!--#include file="master.asp" -->
<% Sub Title %> About Us <% End Sub %>
<% Sub BodyContent %>
<h1>About Us</h1>
<p>
We do things!
</p>
<% End Sub %>
That turns into this HTML when you visit aboutUs.asp
on an IIS server:
<!DOCTYPE html>
<html>
<head>
<title> About Us </title>
</head>
<body>
<h1>About Us</h1>
<p>
We do things!
</p>
</body>
</html>
However, this approach does not allow nesting:
subtemplate.asp
<div class="innerLogo <% LogoSide() %>">
<% LogoImg() %>
</div>
template_user.asp
<!--#include file="master.asp" -->
<% Sub Title %> Our Logo <% End Sub %>
<% Sub BodyContent %>
<!--#include file="subtemplate.asp" -->
<% Sub LogoSide %> leftside <% End Sub %>
<% Sub LogoImg %>
<img src="img/about.png" alt="About" />
<% End Sub %>
<% End Sub %>
This will not work, because nested Sub
s are a syntax error:
Microsoft VBScript compilation error '800a03ea'
Syntax error
/template_user.asp, line 9
Sub LogoSide
^
Since nesting is not allowed, this templating system is, in effect, a one-time solution. If your individual pages’ subroutines become too unwieldy, you can’t use this technique again. So when using this technique, you should carefully choose where to carve out your set of templates in order to provide the best balance between flexibility and DRYness.
<%If true Then%> <!--#include file="A.asp"--> <%Else%> <!--#include file="B.asp"--> <%End If%>
– Roselba<!--#include header.asp-->
"comments" were actually directives. /facepalm. Microsoft once again wins the "dumbest code concept" prize... – Esra