Introduction to using PHP Includes
When includes are used, the server puts the include file (which
is simply a plain text file with a section of HTML code) together
with the page before it's served to the browser. So if you look
at the source code of the page, it looks no different than if the
content were coded right on the page itself - which it is, except
that the server is putting it there for you.
Benefit: When there's a section of text to be updated, only
one single text file has to be updated and uploaded to the
server and the change will show on all the pages it's on without
having to touch them or upload them again.
Using PHP includes is similar to using SSI, but I find it easier
to use PHP includes. For one thing, there are so many other things
that PHP can be used for, and since often it isn't possible to use
SSI and PHP on the same site, I'd rather use PHP so that I have
so many more options available. Like automatically updating dates,
which I've put on a page with PHP
Note: It's a good idea, to keep all of the includes in an
/includes/ folder of their own so that they're easy to find. It's
the same as keeping all the images in an /images/ folder as part
of site organization.
To use them, you just put a simple line of code to "call"
your include file in the html code at the exact spot on the page
you want the text or navigation links to appear on the page in a
This is what the code looks like if the file using the include
is in the root (main) folder of the site:
<?php include ( '/design_development/includes/navigation.html' ); ?>
If the pages using the includes are in a /subdirectory/ this is
what's used, the same way that's used for images:
<?php include ( '/includes/navigation.html' ); ?>
Note that the file uses a .php file extension, which is the proper
way to do it. Typically, pages that use PHP also have a .php file
extension, but a simple entry in your .htaccess file will tell the
server to parse (process and read) pages for PHP that have an .htm
or .html file extension. So if you already use one of those, there's
no reason to have to change.
What I generally do is put my page together with whatever design
I'm using, and when I'm sure it's all how I want it to be, I move
elements that will be on a lot of pages (or all of them) into a
text file and replace with the line of code for the include.