README

This composer package contains a few helper methods for working with imgix and WordPress. This tooling is helpful if you use the WordPress image functions like wp_get_attachment_image() and want your URLs rewritten to imgix URLs.

Further, this package can also rewrite your image URLs to WebP versions if you are not using imgix. Note, this package does not generate WebP images it only rewrites them to WebP if you are not using imgix. If you are using imgix, use imgix to serve WebP images.

Install

In your WordPress theme or plugin.

composer require nullaidev/imgix-wp

Be sure you include the composer's autoload.php.

// Composer
if(file_exists(__DIR__ . '/vendor/autoload.php')) {
    require __DIR__ . '/vendor/autoload.php';
}

Initialize

In your themes functions.php file call \ImgixWp\Core::init(). When no options are used all image URLs created with wp_get_attachment_image_src(), wp_get_attachment_image(), and wp_calculate_image_srcset() will be rewritten as WebP versions.

// functions.php
\ImgixWp\Core::init();

IMPORTANT: If you don't have WebP versions of your images on your server calling \ImgixWp\Core::init() will break your website images leading to 404 errors.

Generate WebP Images

You can generate your own WebP images in WordPress using the cwebp command.

1. First, download and install the cwebp CLI tool.
2. From the command line go to the folder with your images such as wordpress/wp-content/uploads/{year}/{month}.
3. Run the following command.
4. Enjoy your webp images.

# Example from path, wordpress/wp-content/uploads/2021/01
for file in *; do cwebp -q 50 "$file" -o "${file%.*}.webp"; done

imgix Activation

In your themes functions.php file call \ImgixWp\Core::init() and provide your imgix source URL host name (exclude https). The imgix source must point to your wp-content/uploads folder.

// functions.php
\ImgixWp\Core::init([
    'imgix_host' => 'your-source-name-here.imgix.net'
]);

Calling the \ImgixWp\Core::init() method will automatically rewrite all of your image URLs to the imgix URL generated by wp_get_attachment_image_src(), wp_get_attachment_image(), and wp_calculate_image_srcset() when they are using on the front-end of your WordPress website.

Raw URLs within content will not be rewritten to an imgix version.

Helper Functions

To apply the special query parameters to an image when using wp_get_attachment_image() you can use \ImgixWp\Image::getImage() instead. The \ImgixWp\Image::getImage() has the same signature as wp_get_attachment_image() but include another parameter for the query.

For example, to get WebP images served by imgix using the query string ?auto=format you can use the following:

// page.php
$attachment_id = 1;

// WordPress version - ?auto=format is NOT applied
echo wp_get_attachment_image($attachment_id, 'full', false, []);

// imgix version - ?auto=format is applied
echo \ImgixWp\Image::getImage($attachment_id, 'full', false, [], [
    'auto' => 'format'
]);