thumbor.php

<?php
/**
 * Plugin Name:  Thumbor
 * Version:      1.0
 * Plugin URI:   http://codekitchen.eu
 * Description:  Thumbor is an open-source photo thumbnail service. This plugin connects to it.
 * Author:       CodeKitchen B.V.
 * Author URI:   https://codekitchen.eu
 * Text Domain:  thumbor
 * Domain Path:  /languages/
 * License:      GPL v3
 */

Class Thumbor {

	// Settings parameter fpr future implementation
	private $generate_images = false;

	// Private properties for internal usage.
	private $path;
	private $builder;
	private $image_sizes;

	public function __construct() {
		$this->path = plugin_dir_path( __FILE__ );

		$this->load_autoload();
		$this->load_hooks();
	}

	public function load_autoload() {
		if ( file_exists( $this->path . '/vendor/autoload_52.php' ) ) {
			require $this->path . '/vendor/autoload_52.php';
		}
	}

	public function load_hooks() {
		//Fix missing images
		add_filter( 'wp_calculate_image_srcset_meta', array( $this, 'wp_calculate_image_srcset_meta' ), 10, 4 );
		add_filter( 'wp_calculate_image_srcset', array( $this, 'wp_calculate_image_srcset' ), 10, 5 );

		// Add picture element for webp support
		add_filter( 'post_thumbnail_html', array( $this, 'add_picture_element' ), 10, 5 );

		// Add thumbor sources
		add_filter( 'image_downsize', array( $this, 'filter_image_downsize' ), 10, 3 );

		if ( ! $this->generate_images ) {
			// Don't generate image sizes. Thumbor will on the fly do that
			add_filter( 'intermediate_image_sizes_advanced', '__return_false' );
		}
	}


	/**
	 ** PUBLIC API
	 **/

	public function get_thumbor_image( $image_url, $width = 0, $height = 0, $crop = false, $additional_builder_args = array() ) {
		$builder = $this->get_builder();

		// Expose determined arguments to a filter.
		$transform = $crop ? 'crop' : 'fit';

		// Setting up the builder args
		$builder_args = $additional_builder_args;

		if ( empty( $builder_args['format'] ) ) {
			$builder_args['format'] = strtolower( pathinfo( $image_url, PATHINFO_EXTENSION ) );
		}

		if ( $width || $height ) {
			$builder_args[ $transform ] = array(
				'width'  => $width,
				'height' => $height
			);
		}

		// allow with a filter to turn on smart cropping for all images
		$builder_args['smart_crop'] = apply_filters( 'thumbor_builder_smart_crop', true, $image_url, $builder_args );

		// Let people filter the args
		$builder_args = apply_filters( 'thumbor_builder_args', $builder_args, $image_url, $additional_builder_args );

		// Check if image URL should be used.
		if ( ! $builder->validate_image_url( $image_url ) ) {
			return false;
		}

		return (string) $builder->url( $image_url, $builder_args );
	}



	/**
	 ** INTERNAL HELPERS
	 **/

	protected function get_builder() {
		if ( ! $this->builder ) {
			include_once 'thumbor-builder.php';
			$this->builder = new Thumbor_Builder( untrailingslashit( THUMBOR_SERVER ), THUMBOR_SECRET );
		}

		return $this->builder;
	}

	/**
	 * Provide an array of available image sizes and corresponding dimensions.
	 * Similar to get_intermediate_image_sizes() except that it includes image sizes' dimensions, not just their names.
	 *
	 * @global $wp_additional_image_sizes
	 * @uses get_option
	 * @return array
	 */
	protected function get_image_sizes() {
		if ( null == $this->image_sizes ) {
			global $_wp_additional_image_sizes;

			// Populate an array matching the data structure of $_wp_additional_image_sizes so we have a consistent structure for image sizes
			$images = array(
				'thumbnail' => array(
					'width'  => intval( get_option( 'thumbnail_size_w' ) ),
					'height' => intval( get_option( 'thumbnail_size_h' ) ),
					'crop'   => (bool) get_option( 'thumbnail_crop' )
				),
				'medium' => array(
					'width'  => intval( get_option( 'medium_size_w' ) ),
					'height' => intval( get_option( 'medium_size_h' ) ),
					'crop'   => false
				),
				'large' => array(
					'width'  => intval( get_option( 'large_size_w' ) ),
					'height' => intval( get_option( 'large_size_h' ) ),
					'crop'   => false
				),
				'full' => array(
					'width'  => null,
					'height' => null,
					'crop'   => false
				)
			);

			// Update class variable, merging in $_wp_additional_image_sizes if any are set
			if ( is_array( $_wp_additional_image_sizes ) && ! empty( $_wp_additional_image_sizes ) ) {
				$this->image_sizes = array_merge( $images, $_wp_additional_image_sizes );
			}
			else {
				$this->image_sizes = $images;
			}
		}

		return is_array( $this->image_sizes ) ? $this->image_sizes : array();
	}


	/**
	 ** HOOKS
	 **/

	public function wp_calculate_image_srcset_meta( $image_meta, $size_array, $image_src, $attachment_id ) {
		$sizes = $this->get_image_sizes();

		foreach ( $sizes as $key => $size ) {
			$image_meta['sizes'][ $key ] = array(
				'file'      => '',
				'width'     => $size['width'],
				'height'    => $size['height']
			);
		}

		return $image_meta;
	}

	public function wp_calculate_image_srcset( $sources, $size_array, $image_src, $image_meta, $attachment_id ) {
		$image_src      = wp_get_attachment_url( $attachment_id );
		$sizes          = $this->get_image_sizes();
		$sizes_by_width = array();

		foreach ( $sizes as $key => $size ) {
			$sizes_by_width[ $size['width'] ] = $size;
		}

		foreach ( $sources as $key => &$value ) {
			$size         = $sizes_by_width[ $key ];
			$value['url'] = $this->get_thumbor_image(
				$image_src,
				$size['width'],
				$size['height'],
				$size['crop'],
				array(
					'format' => isset( $image_meta['format'] ) ? $image_meta['format'] : ''
				)
			);
		}

		return $sources;
	}

	public function add_picture_element( $html, $post_id, $post_thumbnail_id, $size, $attr ) {
		// Don't continue if there is no html
		if ( ! $html ) {
			return $html;
		}

		$doc = new DOMDocument();
		$doc->loadHTML($html);
		$xpath    = new DOMXPath($doc);
		$nodelist = $xpath->query("//img");
		$node     = $nodelist->item(0); // gets the 1st image

		// Don't continue if there is no image
		if ( ! $node ) {
			return;
		}
	
		$width    = $node->attributes->getNamedItem('width')->nodeValue;
		$height   = $node->attributes->getNamedItem('height')->nodeValue;
		$src      = $node->attributes->getNamedItem('src')->nodeValue;
		$class    = $node->attributes->getNamedItem('class')->nodeValue;
		$alt      = $node->attributes->getNamedItem('alt')->nodeValue;

		if ( $node->attributes->getNamedItem('srcset') ) {
			$srcset = $node->attributes->getNamedItem('srcset')->nodeValue;
			$sizes  = $node->attributes->getNamedItem('sizes')->nodeValue;

			$image_meta = wp_get_attachment_metadata( $post_thumbnail_id );
			$image_meta['format'] = 'webp';

			$size_array = array( absint( $width ), absint( $height ) );
			$srcset2    = wp_calculate_image_srcset( $size_array, $src, $image_meta, $post_thumbnail_id );
			$sizes2     = wp_calculate_image_sizes( $size_array, $src, $image_meta, $post_thumbnail_id );
		}
		else {
			$srcset = $sizes  = '';

			$srcset2 = '';
			$sizes2  = '';
		}

		$html  = '<picture>';
		$html .= '<source srcset="' . $srcset2 . '" sizes="' . $sizes2 . '" type="image/webp" />';
		$html .= '<source srcset="' . $srcset . '" sizes="' . $sizes . '" />';
		$html .= '<img width="' . $width . '" height="' . $height . '" src="' . $src . '" class="' . $class . '" alt="' . $alt . '" />';
		$html .= '</picture>';

		return $html;
	}


	public function filter_image_downsize( $image, $attachment_id, $size ) {
		// Don't foul up the admin side of things when images are being generated
		if ( $this->generate_images && is_admin() ) {
			return $image;
		}

		// Provide plugins a way of preventing this plugin from being applied to images.
		if ( apply_filters( 'thumbor_override_image_downsize', false, compact( 'image', 'attachment_id', 'size' ) ) ) {
			return $image;
		}

		// Get the image URL.
		$image_url = wp_get_attachment_url( $attachment_id );

		if ( $image_url ) {
			// If an image is requested with a size known to WordPress, use that size's settings.
			if ( ( is_string( $size ) || is_int( $size ) ) && array_key_exists( $size, $this->get_image_sizes() ) ) {
				$image_args = self::get_image_sizes();
				$image_args = $image_args[ $size ];

				// `full` is a special case in WP
				// To ensure filter receives consistent data regardless of requested size, `$image_args` is overridden with dimensions of original image.
				if ( 'full' == $size ) {
					$image_meta = wp_get_attachment_metadata( $attachment_id );
					if ( isset( $image_meta['width'], $image_meta['height'] ) ) {
						$image_args = array(
							'width'  => $image_meta['width'],
							'height' => $image_meta['height'],
							'crop'   => false
						);
					}
				}

				if ( ! $image_args['crop'] && $image_meta = wp_get_attachment_metadata( $attachment_id ) ) {
					// Lets make sure that we don't upscale images since wp never upscales them as well
					$smaller_width  = ( ( $image_meta['width']  < $image_args['width']  ) ? $image_meta['width']  : $image_args['width'] );
					$smaller_height = ( ( $image_meta['height'] < $image_args['height'] ) ? $image_meta['height'] : $image_args['height'] );

					// Set new width & height
					$image_args['width']  = $smaller_width;
					$image_args['height'] = $smaller_height;
				}
			}
			elseif ( is_array( $size ) ) {
				// Pull width and height values from the provided array, if possible
				$image_args['width']  = isset( $size[0] ) ? (int) $size[0] : false;
				$image_args['height'] = isset( $size[1] ) ? (int) $size[1] : false;
				$image_args['crop']   = false;

				// Don't bother if necessary parameters aren't passed.
				if ( ! $image_args['width'] && ! $image_args['height'] ) {
					return $image;
				}
			}

			$thumbor_url = $this->get_thumbor_image( $image_url, $image_args['width'], $image_args['height'], $image_args['crop'] );

			if ( isset( $_REQUEST['action'] ) && 'query-attachments' == $_REQUEST['action'] ) {
				$image_args['crop'] = true;
			}

			if ( $thumbor_url ) {
				// Generate URL
				$image = array(
					$thumbor_url,
					$image_args['width'],
					$image_args['height'],
					$image_args['crop']
				);
			}

		}

		return $image;
	}

}

if ( defined( 'THUMBOR_SERVER' ) && defined( 'THUMBOR_SECRET' ) ) {
	$GLOBALS['thumbor'] = new Thumbor;
}