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 years programming knowledge and site administrator of www.webforumz.com - Copyright 2003-2004
best cleaning company Lincolnshire ..Cost Effective Advertising. Online selling. Increased geopgraphic range. Wider... Read More
Your content is what gets you in search engines, speaks... Read More
The "robots" meta tag, when used properly, will tell the... Read More
Understanding and using web analytics.In recent years, website marketers were... Read More
Knowledge is power.And undoubtedly, it is the key to making... Read More
Although there are significant differences among the various types of... Read More
Recently, a friend asked "What's the deal with those DIY... Read More
Q1.Why would I need a web site? A1.- Improve my... Read More
There are hundreds of millions of Web surfers today. Each... Read More
People often come to me in a state of crisis... Read More
Just starting out, you can start with a simple informational... Read More
Creating and maintaining an effective presence on the Web has... Read More
When I set up my website I felt paypal was... Read More
The DDA (Disability Discrimination Act) states that service providers must... Read More
If you're an up and coming graphic/web designer just out... Read More
Can you imagine the hypocrisy of spending thousands of dollars,... Read More
In 1995 a new era of accessibility for disabled people... Read More
Build it and they will come is not always true;... Read More
Starting a business online is no longer as difficult as... Read More
You work hard to build traffic to your web page.... Read More
Building a new website can be a lengthy task. From... Read More
When most people build a web site, they think one... Read More
Starting and maintaining a business is challenging enough without the... Read More
This is a growing concern amongst many business owners. Does... Read More
Optimal website design is the art of logical navigation.It will... Read More
on demand house cleaning Lake Forest ..With the New Year upon us yet again, it's time... Read More
A system development process can follow a number of standard... Read More
How can we add Word Rich Content to our Websites... Read More
This simple question can take on several different forms, but... Read More
I still remember it very clear ... It was almost... Read More
An automated accessibility tool is a piece of software which... Read More
The DDA (Disability Discrimination Act) states that service providers must... Read More
It may come as some surprise to a traditionally off-line... Read More
My life's greatest passion is a safari hobby. And what... Read More
"How do I improve web site sales figures?" The CEO... Read More
You have permission to publish this article electronically, in print,... Read More
With all of the factors involved in designing and building... Read More
The DDA (Disability Discrimination Act) states that service providers must... Read More
If you don't have a web site yet, are thinking... Read More
People like to get immediate responses to requests. Autoresponders are... Read More
When you consider the billions of individuals and companies on... Read More
I've heard several prominent web marketers mention in their classes... Read More
In the late 1990's three San Francisco based web developers... Read More
Often time I've browsed sites and seen the same thing... Read More
The definition of the phrase "Content Management" depends on what... Read More
One of the most important parts of establishing a new... Read More
It's now easier than ever to take payments on the... Read More
--------------------------------Why Should You Create a website?--------------------------------A. What do you want... Read More
How popular is online shopping? And is there room for... Read More
Any new website competing on the internet, needs to take... Read More
Web Development |