webhosting Web Hosting Wit.Com

Webhosting, Server and Web Site Help & Information
Internet Services
  Domain Names
  Web Hosting
  Accept Credit Cards
  SSL Certificates
  T1 Connections
 
Coding Tutorials
  HTML Tags
  HTML Code
  Style Sheets
  Javascript
  PHP Tutorial
  ASP Tutorial
  SQL (Database)
  ASP Code
  HTML Templates
 
Tips & Tricks
  Design Dos & Don'ts
  HTML Tips
  Useful Applications
  Search Engines
  My IP Lookup
 
Charts
Web Design
Help Articles
Contact Us
Home Page
 
html basic code
Domain Names SSL Certificates Web Hosting

Server Side Includes (SSI) with ASP


Server Side Includes (SSI) with ASP

People often have identical sections of code spread throughout many ASP pages, typically code at the top of the page (usually referred to as the header) and the lower part of the page (the footer). Similarly, you may have code that performs a certain set of instructions that you are repeating across multiple pages. Consider an example:-

<%
If foobar="yes" then
response.write "YES!"
Else
response.write "NOT YES!"
End if
%>

Ok, ok... it's simple, but imagine that you used this on multiple pages. What's wrong with this picture?

Well... you don't have to think about that long before realising that if you ever wanted to change something about that piece of code, you'd have your work cut out. you would have to change every page... everyone has done this at some stage and luckily most usually take the steps to learn a way around this problem.

If we could save our valuable chunk of code into a file and have that file accessed whenever we needed the code, then we no longer have a problem when it comes to changing things, as we simply update one file. Include files or Server Side Includes (SSI) as they are more commonly known are a powerful way to not only save time when it comes to maintaining and updating a site, but also increase efficiency and speed of that site too!

Ok, lets see how we use an include file... to start with we need to use one of two methods. The first one allows for including files relatively. By that I mean relative to the directory the ASP file that is using the include file resides. The second method includes files virtually. Including files virtually means that the path is taken from the root directory.

Consider that we are going to have a file (/main/somefile.asp) include another file (/includes/someinclude.asp).

To demonstrate, relative inclusion, look at this:-

<%
Response.Write "executing included code now"
%>
<!--#include file="../includes/someinclude.asp"-->
<%
Response.write "done executing included code"
%>

And here, we give an example of the other method, virtual inclusion:-

<%
Response.Write "executing included code now"
%>
<!--#include virtual="/includes/someinclude.asp"-->
<%
Response.write "done executing included code"
%>

Note the slight difference between the two methods. With virtual inclusion, you can move the file that calls upon the include file anywhere without affecting the outcome, because the path is always relative to the root. The same cannot be said however for relative inclusion. If you move a file that is using relative inclusion to a different directory, you'll most likely find the relative path is no longer correct.

From the examples above, you may also notice that both methods, when calling the include do so OUTSIDE of the ASP script block. This because #include declarations are not interpreted by ASP. Include files are included before a single line of ASP is processed which means the following WONT work:-

%lt;%
Page=request.form("page")
%>
<!--#include file="../includes/<%=page%>.asp"-->

We were attempting to perform a dynamic include and I would be the first to admit that the above would be very useful indeed if in fact it were possible. I do intend to cover a few methods that work around this set back but I know you will now be itching to get started right away on using include files to even worry about this, so I will cover it in a future article.

I hope that you have found the above informative and hope it inspires you all to write code that's more efficient and more easily maintained.

Rob Collyer,experienced with 20 yearsprogramming knowledge andsite administratorof www.webforumz.com- Copyright 2003-2004


MORE RESOURCES:


If you have any information you would like to add to the site e-mail it to webmaster@webhostingwit.com

2006 Web Hosting Wit.Com and its licensors. All Rights Reserved