Hook priority and arguments in Wordpress - Mini Project: Build & Apply

Hook Priority and Arguments in WordPress

📖 Scenario: You are building a simple WordPress plugin that modifies the footer text. You want to learn how to use hooks with different priorities and how to pass and use arguments in your hooked functions.

🎯 Goal: Create a WordPress plugin that uses the add_filter hook to change the footer text. You will set up the hook with different priorities and handle arguments passed to the hooked function.

📋 What You'll Learn

Create a function that modifies the footer text

Use add_filter to hook the function to admin_footer_text

Set a custom priority for the hook

Make the hooked function accept and use arguments passed by the hook

💡 Why This Matters

🌍 Real World

WordPress developers often customize themes and plugins by using hooks with specific priorities and arguments to control how and when their code runs.

💼 Career

Understanding hook priority and arguments is essential for WordPress plugin and theme development jobs, enabling developers to write clean, compatible, and maintainable code.

1

Create the footer text function

Create a function called custom_footer_text that takes one argument called $text and returns the string 'Custom footer text.'

Wordpress

# Your code here

Need a hint?

Define a function with one parameter and return the exact string.

2

Hook the function to admin_footer_text with default priority

Use add_filter to hook the function custom_footer_text to the admin_footer_text hook with the default priority and specify that it accepts 1 argument.

Wordpress

<?php
function custom_footer_text($text) {
    return 'Custom footer text.';
}

# Your code here

Need a hint?

Use add_filter with priority 10 and 1 argument.

3

Change the hook priority to 20

Modify the add_filter call to set the priority to 20 while keeping the function name custom_footer_text, hook admin_footer_text, and 1 argument.

Wordpress

<?php
function custom_footer_text($text) {
    return 'Custom footer text.';
}

# Your code here

Need a hint?

Change the priority number to 20 in the add_filter call.

4

Modify the function to append text using the argument

Change the custom_footer_text function so it appends the string ' - Powered by WordPress' to the $text argument and returns the combined string.

Wordpress

<?php
function custom_footer_text($text) {
    # Your code here
}

add_filter('admin_footer_text', 'custom_footer_text', 20, 1);

Need a hint?

Use string concatenation to add the extra text to the argument.