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
disinfecting cleaning services Arlington Heights ..There have been many significant changes to the face of... Read More
Is your website Really useful?I had a 'rep' in yesterday... Read More
When you consider the billions of individuals and companies on... Read More
Many executives and investors are skeptical that software products can... Read More
In about the Time it takes to Watch a Reality... Read More
Now that you have got your domain name registered, your... Read More
That's right. According to a recent study by Nielsen/NetRatings, Amazon.com... Read More
"Don't Sell the Steak, Sell the Sizzle."Have you heard of... Read More
A website is the most versatile and cost-effective marketing tool... Read More
Most web sites are more like stage sets than real... Read More
Although there are significant differences among the various types of... Read More
Most interactive websites nowadays require data to be presented dynamically... Read More
What do you mean, you don't have a website for... Read More
Every small business owner knows that they need a website,... Read More
The evolution of web development parallels the model of technology... Read More
I'm one of those people that always wanted a website,... Read More
So you want to have a website. You have gone... Read More
What happened on your website yesterday? What about last week... Read More
1) Word of Mouth The single most powerful form of... Read More
Looks like every client wants a Flash site these days... Read More
In the time that I have been using the Internet,... Read More
As increasing numbers of people search for information on the... Read More
Any new website competing on the internet, needs to take... Read More
Does My Web Site Require A Web Database?If your web... Read More
How do you decide on the content, products and or... Read More
bathroom cleaning service Mundelein ..Web accessibility has so many benefits that I really do... Read More
A while ago one of my clients approached me and... Read More
The first thing you will have to deal building your... Read More
First, using a lot of web graphics, flash, banners and... Read More
Everyday thousands of new businesses make the leap and take... Read More
Everywhere you look these days, people are telling you that... Read More
1. The first page appears quickly.It's a good way to... Read More
If you're looking for better web site ROI, chances are,... Read More
One of the things that many people overlook when building... Read More
Starting a business online is no longer as difficult as... Read More
The big thing these days is your ability to capture... Read More
Is Your Web Site an Expense or an Investment?Why don't... Read More
Have you ever thought the secret behind the success of... Read More
That's right. Your method, behavior and strategy you are now... Read More
Part of the success of most home-based businesses is their... Read More
There have been many significant changes to the face of... Read More
Thousands of people are now making a living online and... Read More
If one more business owner tells me their website sucks... Read More
Wow, we`ve already taken a domain and chosen a web... Read More
Functions and Subroutines in ASP If you read... Read More
1. As the first step, "Hire a web designer."First create... Read More
Directory Generator, a product from Armand Morin and Marc Quarles,... Read More
Having an eye catching website is great, but are you... Read More
Getting a Targeted Visitor to a website is a waste... Read More
If you are looking for creating your online presence you... Read More
Web Development |