HomePHP Page 10 - Building an Extensible Menu Class
Extending Yourself - PHP
So you know the theory behind OOP, but don't really understandits applications? Well, it's time to take objects out of the classroom andinto the real world - this article demonstrates how OOP can save you timeand effort by building a PHP-based Menu object to describe therelationships in a hierarchical menu tree. And since the proof of thepudding is in the eating, it then combines the newly-minted Menu objectwith some of the most popular JavaScript menu systems available online toshow you how cool objects really are.
All the examples you've seen thus far have used the same standard API defined within the Menu object. However, this assumes one important thing - that a database table (in the format described) has already been created and populated with menu records. In case this is an unreasonable assumption for your specific requirements, you might consider adding a few method calls to add and delete nodes respectively.
<?
class Menu
{
// other methods
// function: add a record to the menu table
function create_node($label, $link, $parent)
{
$this->query("INSERT INTO $this->table(label, link, parent) VALUES
('$label', '$link', '$parent')");
}
// function: remove a record from the menu table
function remove_node($id)
{
$this->query("DELETE FROM $this->table WHERE id = '$id'");
}
}
?>
You might also want to consider developing a simple
administration interface to these method calls, so that users can easily modify the menu tree via a GUI.
And that's about all for the moment. In this article, you expanded your knowledge of PHP's OOP capabilities by actually using all that theory to build something useful - a menu widget which can be used to describe the relationships within a hierarchical menu system, independent of how the menu is visually presented.
If you work with menu systems, whether on a Web site, within a Web application or on an embedded system, you might find this object a handy tool in your next development effort. If you're a novice programmer struggling to understand how OOP can make your life easier, I hope this article offered some pointers, as well as some illustration of how object-oriented programming works. And if you don't fit into either of those categories - well, I hope you found it interesting and informative, anyway.
See you soon!
Note: All examples in this article have been tested on Linux/i586 with PHP4, HIERmenus 4.0.12, and FolderTree 2.0. HIERmenus and FolderTree copyright their respective authors. Examples are illustrative only, and are not meant for a production environment. YMMV!
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