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Anyone who's ever
had to change a multitude of static pages on a site knows what a pain
it is to find and change the same snippets of code on one page after
another - even using an Html editor's find-and-replace function can be
cumbersome since you have to upload all of the pages to the server
again with the new code.
Sometimes a page or two will get missed or the find-and-replace
function replaces some things you didn't intend to change, so
it requires some quality-checking time to run through all the pages
and make sure the changes are there.
An easier way to manage pages in your site is by replacing chunks
of repeating code, such as your navigation links, with server
side include (SSI) files.
Instead of repeating the same code over and over, you create a separate
file with just that chunk of repeated code in it, then place a line of
code on each page that tells the server to insert the
contents of a separate file into that spot on the page.
When someone visits your page, the server scans the code,
pulls in the files needed to assemble that page and returns the page
as a single, complete page to the browser.
Your "includes" code is replaced by the contents
of the file the code called.
Since this all happens on the server's side of the
transaction, your visitors don't need to have any special browsers or
plug-ins in order to make this work; SSI returns a "normal"
html page to the browser.
SSI files can simplify the maintenance of your site.
Information that may change from time to time or that replicates
across many pages can be replaced with SSI files.
Then, when you alter that include file, every page on your
website changes where the included file is being read.
You will find include files often being used to replace the entire header
and footer for each page.
When set up as includes, the background
color, graphics, navigation, or copyright
information can be changed across the entire site by
altering the include file for that information.
Without includes, you would be forced to go through all
your pages to make the necessary changes.
You can use as many includes files on a page as you need
- you can also call different includes files for different
pages.
A good example is sub navigation links that only appear on
certain pages, you only call that include file where it's required.
Any block of code in your site that repeats across pages is a
good candidate for SSI.
The format for the code you will use to include a file
within an Html page will depend on the operating system
of your server. For most sites, this will mean either Windows
or Unix/Linux.
If you are using Windows, you'll be
changing your file extensions to .asp.
For Linux/Unix systems, you will use .php
extensions.
You should check with your web host or server administrator if you
are not sure what platform your site is hosted on.
Here are the two standard file include methods for both Windows
and Linux systems (Note: you must use the
proper file extensions [.asp or .php] in order for these
functions to work.)
Remember, the included file will process just as regular
Html; all you are doing is splitting your pages into manageable
parts for easy editing and maintenance:
Windows (.asp)
<!--#INCLUDE FILE="header.asp"-->
- Create a file called header.asp that only contains the
code that you want to include.
- Include the file with the above code in the place
where the code should appear on each page.
- Name all files with a .asp extension.
Linux/Unix (.php)
<? include("header.php");
?>
- Create a file called header.php that only contains the
code that you want to include.
- Include the file with the above code in the place where
the code should appear on each page.
- Name all files with a .php extension.
In both cases, relative paths can be determined as in HTML,
such as:
<? include("../header.php"); ?>
or you can use an absolute (full) path, which is
ideal for sites that have multiple levels of folders in their
structure:
<? include("http:www.site.com/header.php"); ?>
Changing the extensions of your pages can be a temporary
headache, especially for established sites but in the long run,
the ease of maintaining and changing the site is worth the effort.
Before changing page extensions, be sure to have a custom 404
error page in place. (Most hosting packages today offer custom 404
page tools in their control panels - contact your host if you don't
see an option in your hosting control panel.)
SSI gives you the flexibility of a framed site without all
the usability issues that come along with frames.
It allows you to separate the page content from the structure
and graphics, giving you the freedom to easily change any
consistent element of the site without a major hassle.
It's worth changing existing sites and should definitely be
considered when planning a new site.
Copyright © 2004 by Scottie Claiborne
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