PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Writing the Code for Your Class
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puts a single menu button. If the button is to point to the page you are on, you display
an inactive button instead, which looks slightly different and does not link anywhere.
This way, you can keep the page layout consistent and provide visitors with a visual
location.
The operation IsURLCurrentPage() determines whether the URL for a button
points to the current page.You can use several techniques to discover this information.
Here, you use the string function strpos() to see whether the URL given is contained
in one of the server set variables.The statement strpos( $_SERVER['PHP_SELF'], $url )
returns a number if the string in $url is inside the superglobal variable
$_SERVER['PHP_SELF'] or false if it is not.
To use this Page class, you need to include page.inc in a script and call Display().
The code in Listing 6.2 creates TLA Consulting’s home page and gives output similar
to that previously generated in Figure 5.2.The code in Listing 6.2 does the following:
1. Uses require to include the contents of page.inc, which contains the definition
of the class Page.
2. Creates an instance of the class Page.The instance is called $homepage.
3. Sets the content, consisting of some text and HTML tags to appear in the page.
(This implicitly invokes the __set() method.)
4. Calls the operation Display() within the object $homepage to cause the page to
be displayed in the visitor’s browser.
Listing 6.2 home.php—This Home Page Uses the Page Class to Do Most of the Work
Involved in Generating the Page
You can see in Listing 6.2 that you need to do very little work to generate new pages
using this Page class. Using the class in this way means that all your pages need to be
very similar.
If you want some sections of the site to use a variant of the standard page, you can
simply copy page.inc to a new file called page2.inc and make some changes.This
means that every time you update or fix parts of page.inc, you need to remember to
make the same changes to page2.inc.
A better course of action is to use inheritance to create a new class that inherits most