Avoiding conflicting function names

Remember from Chapter 1 that WordPress' architecture normally relies on globally scoped functions in the main namespace, so name collisions are a big concern. In layman's terms, each function must have a unique name to avoid PHP errors. For example, the following PHP script would die with a fatal error:

<?php
function main() {
    // Do something
}

function main() {
    // Oops... "Fatal error: Cannot redeclare main()"              
}
?>

Even if the functions are declared in different files, the names must be unique. As we write plugins, we must be careful to avoid using function names that are already in use by WordPress or by other plugins.

In this chapter, we will ensure unique function names by adding a prefix to each name, for example, my_plugin_main() or my_plugin_some_function . Usually this prefix is inspired by your plugin's name. We're naming our plugin Digg This, so we've used "diggthis" as a prefix to each function's name.

In later chapters, we will show you how to avoid conflicting function names by using PHP classes, objects, and static functions. Object-oriented coding represents a cleaner solution to the problem of namespace pollution, but it is a bit harder to follow, so we have dedicated this chapter to show you how we solved this problem using simple function names. We'll tackle the more advanced solutions later.