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
personalized cleaning services Des Plaines ..A company must earn and keep trust or sales don't... Read More
One of my most salient memories from when I sold... Read More
I talk with so many people who have small businesses... Read More
There are hundreds of millions of Web surfers today. Each... Read More
Keywords in Search Engine Optimizing and Search Engine Marketing are... Read More
You hear a great deal about the Internet these days... Read More
As a business you can't afford to ignore the Internet... Read More
One of the things that Internet excels is disseminating information... Read More
Most interactive websites nowadays require data to be presented dynamically... Read More
If you were asked to put a value on your... Read More
The cost of setting up a web site is dirt... Read More
This simple question can take on several different forms, but... Read More
Cost Effective Advertising. Online selling. Increased geopgraphic range. Wider... Read More
The first thing my business consultant (read brother-in-law) asked me,... Read More
Although there are significant differences among the various types of... Read More
The Disability Discrimination Act says that websites must be made... Read More
So you want to take a look at a real... Read More
In the big, wide online world there are millions of... Read More
From early days of www, the Internet sites that are... Read More
Did you know that hosting companies overcrowd their servers despite... Read More
Affiliate programs are a great way to earn an income... Read More
Any new website competing on the internet, needs to take... Read More
The Disability Discrimination Act states that service providers must not... Read More
If you like the Internet and surfing through the billions... Read More
Web sites are not just places to sell things; they... Read More
family-safe home cleaners Arlington Heights ..Many millions of dollars are being wasted on promoting and... Read More
"Don't Sell the Steak, Sell the Sizzle."Have you heard of... Read More
What is the most important part of your online business?Many... Read More
One of the most important parts of establishing a new... Read More
How popular is online shopping? And is there room for... Read More
1. The first page appears quickly.It's a good way to... Read More
Absolutely everything stems from the purpose of your website -... Read More
In this day and age most businesses consider having their... Read More
If you like the Internet and surfing through the billions... Read More
I'm a freelance programmer and somehow I managed to get... Read More
One of the most useful features offered by some web... Read More
Looks like every client wants a Flash site these days... Read More
The Internet car buyer is an elusive animal. Trying to... Read More
RIVERSIDE, CA August 4, 2004 ?- "Historically, small business owners... Read More
See how you can create graphic effects on text with... Read More
With all of the factors involved in designing and building... Read More
You want to give your site's visitors a way to... Read More
The first thing you will have to deal building your... Read More
Revenues are often lost because many business owners don't see... Read More
Spend time planning your Web site. Before you design a... Read More
Three way linking and concerns.For many years SEO experts were... Read More
What is CSS?CSS is a simple file which controls the... Read More
So your traffic is going through the roof yeah? It's... Read More
The definition of the phrase "Content Management" depends on what... Read More
Website, website, website, everyone says you need one. But do... Read More
Web Development |