Filter hooks in Wordpress - Mini Project: Build & Apply

Using Filter Hooks in WordPress

📖 Scenario: You are customizing a WordPress site. You want to change how the title appears by using a filter hook.

🎯 Goal: Learn how to create a filter hook function and apply it to modify the title text.

📋 What You'll Learn

Create a function to modify the title

Add a filter hook to apply the function

Use the correct WordPress filter hook name

Return the modified title from the function

💡 Why This Matters

🌍 Real World

Filter hooks let you change WordPress data without editing core files. This is useful for customizing titles, content, and more.

💼 Career

Understanding filter hooks is essential for WordPress developers to create plugins and themes that modify site behavior safely and cleanly.

1

Create the filter function

Create a function called custom_site_title that takes one parameter called $title and returns the string 'Welcome: ' . $title.

Wordpress

# Your code here

Need a hint?

Define a function that adds 'Welcome: ' before the original title and returns it.

2

Add the filter hook

Use add_filter to attach the function custom_site_title to the WordPress filter hook named 'the_title'.

Wordpress

<?php
function custom_site_title($title) {
    return 'Welcome: ' . $title;
}

# Your code here

Need a hint?

Use add_filter('the_title', 'custom_site_title'); to connect your function to the title filter.

3

Test with a sample title

Create a variable called $sample_title and set it to 'My Blog'. Then apply the filter the_title to $sample_title using apply_filters and store the result in $filtered_title.

Wordpress

<?php
function custom_site_title($title) {
    return 'Welcome: ' . $title;
}

add_filter('the_title', 'custom_site_title');

# Your code here

Need a hint?

Use apply_filters('the_title', $sample_title) to get the filtered title.

4

Complete the filter hook setup

Add a comment above the function custom_site_title that says // Filter hook to add a welcome prefix to titles.

Wordpress

<?php
# Your code here
function custom_site_title($title) {
    return 'Welcome: ' . $title;
}

add_filter('the_title', 'custom_site_title');

$sample_title = 'My Blog';
$filtered_title = apply_filters('the_title', $sample_title);

Need a hint?

Add a descriptive comment to explain the purpose of the filter function.