<?php
class Jetpack_Photon {
/**
* Class variables
*/
// Oh look, a singleton
private static $__instance = null;
// Allowed extensions must match http://code.trac.wordpress.org/browser/photon/index.php#L31
protected static $extensions = array(
'gif',
'jpg',
'jpeg',
'png'
);
// Don't access this directly. Instead, use self::image_sizes() so it's actually populated with something.
protected static $image_sizes = null;
/**
* Singleton implementation
*
* @return object
*/
public static function instance() {
if ( ! is_a( self::$__instance, 'Jetpack_Photon' ) ) {
self::$__instance = new Jetpack_Photon;
self::$__instance->setup();
}
return self::$__instance;
}
/**
* Silence is golden.
*/
private function __construct() {}
/**
* Register actions and filters, but only if basic Photon functions are available.
* The basic functions are found in ./functions.photon.php.
*
* @uses add_action, add_filter
* @return null
*/
private function setup() {
// Display warning if site is private
add_action( 'jetpack_activate_module_photon', array( $this, 'action_jetpack_activate_module_photon' ) );
if ( ! function_exists( 'jetpack_photon_url' ) )
return;
// Images in post content and galleries
add_filter( 'the_content', array( __CLASS__, 'filter_the_content' ), 999999 );
add_filter( 'get_post_gallery', array( __CLASS__, 'filter_the_content' ), 999999 );
// Core image retrieval
add_filter( 'image_downsize', array( $this, 'filter_image_downsize' ), 10, 3 );
// Helpers for maniuplated images
add_action( 'wp_enqueue_scripts', array( $this, 'action_wp_enqueue_scripts' ), 9 );
}
/**
* Check if site is private and warn user if it is
*
* @uses Jetpack::check_privacy
* @action jetpack_activate_module_photon
* @return null
*/
public function action_jetpack_activate_module_photon() {
Jetpack::check_privacy( __FILE__ );
}
/**
** IN-CONTENT IMAGE MANIPULATION FUNCTIONS
**/
/**
* Match all images and any relevant <a> tags in a block of HTML.
*
* @param string $content Some HTML.
* @return array An array of $images matches, where $images[0] is
* an array of full matches, and the link_url, img_tag,
* and img_url keys are arrays of those matches.
*/
public static function parse_images_from_html( $content ) {
$images = array();
if ( preg_match_all( '#(?:<a[^>]+?href=["|\'](?P<link_url>[^\s]+?)["|\'][^>]*?>\s*)?(?P<img_tag><img[^>]+?src=["|\'](?P<img_url>[^\s]+?)["|\'].*?>){1}(?:\s*</a>)?#is', $content, $images ) ) {
foreach ( $images as $key => $unused ) {
// Simplify the output as much as possible, mostly for confirming test results.
if ( is_numeric( $key ) && $key > 0 )
unset( $images[$key] );
}
return $images;
}
return array();
}
/**
* Try to determine height and width from strings WP appends to resized image filenames.
*
* @param string $src The image URL.
* @return array An array consisting of width and height.
*/
public static function parse_dimensions_from_filename( $src ) {
$width_height_string = array();
if ( preg_match( '#-(\d+)x(\d+)\.(?:' . implode('|', self::$extensions ) . '){1}$#i', $src, $width_height_string ) ) {
$width = (int) $width_height_string[1];
$height = (int) $width_height_string[2];
if ( $width && $height )
return array( $width, $height );
}
return array( false, false );
}
/**
* Identify images in post content, and if images are local (uploaded to the current site), pass through Photon.
*
* @param string $content
* @uses self::validate_image_url, apply_filters, jetpack_photon_url, esc_url
* @filter the_content
* @return string
*/
public static function filter_the_content( $content ) {
$images = Jetpack_Photon::parse_images_from_html( $content );
if ( ! empty( $images ) ) {
$content_width = Jetpack::get_content_width();
$image_sizes = self::image_sizes();
$upload_dir = wp_upload_dir();
foreach ( $images[0] as $index => $tag ) {
// Default to resize, though fit may be used in certain cases where a dimension cannot be ascertained
$transform = 'resize';
// Start with a clean attachment ID each time
$attachment_id = false;
// Flag if we need to munge a fullsize URL
$fullsize_url = false;
// Identify image source
$src = $src_orig = $images['img_url'][ $index ];
// Allow specific images to be skipped
if ( apply_filters( 'jetpack_photon_skip_image', false, $src, $tag ) )
continue;
// Support Automattic's Lazy Load plugin
// Can't modify $tag yet as we need unadulterated version later
if ( preg_match( '#data-lazy-src=["|\'](.+?)["|\']#i', $images['img_tag'][ $index ], $lazy_load_src ) ) {
$placeholder_src = $placeholder_src_orig = $src;
$src = $src_orig = $lazy_load_src[1];
}
// Check if image URL should be used with Photon
if ( self::validate_image_url( $src ) ) {
// Find the width and height attributes
$width = $height = false;
// First, check the image tag
if ( preg_match( '#width=["|\']?([\d%]+)["|\']?#i', $images['img_tag'][ $index ], $width_string ) )
$width = $width_string[1];
if ( preg_match( '#height=["|\']?([\d%]+)["|\']?#i', $images['img_tag'][ $index ], $height_string ) )
$height = $height_string[1];
// Can't pass both a relative width and height, so unset the height in favor of not breaking the horizontal layout.
if ( false !== strpos( $width, '%' ) && false !== strpos( $height, '%' ) )
$width = $height = false;
// Detect WP registered image size from HTML class
if ( preg_match( '#class=["|\']?[^"\']*size-([^"\'\s]+)[^"\']*["|\']?#i', $images['img_tag'][ $index ], $size ) ) {
$size = array_pop( $size );
if ( false === $width && false === $height && 'full' != $size && array_key_exists( $size, $image_sizes ) ) {
$width = (int) $image_sizes[ $size ]['width'];
$height = (int) $image_sizes[ $size ]['height'];
$transform = $image_sizes[ $size ]['crop'] ? 'resize' : 'fit';
}
} else {
unset( $size );
}
// WP Attachment ID, if uploaded to this site
if ( preg_match( '#class=["|\']?[^"\']*wp-image-([\d]+)[^"\']*["|\']?#i', $images['img_tag'][ $index ], $attachment_id ) && ( 0 === strpos( $src, $upload_dir['baseurl'] ) || apply_filters( 'jetpack_photon_image_is_local', false, compact( 'src', 'tag', 'images', 'index' ) ) ) ) {
$attachment_id = intval( array_pop( $attachment_id ) );
if ( $attachment_id ) {
$attachment = get_post( $attachment_id );
// Basic check on returned post object
if ( is_object( $attachment ) && ! is_wp_error( $attachment ) && 'attachment' == $attachment->post_type ) {
$src_per_wp = wp_get_attachment_image_src( $attachment_id, isset( $size ) ? $size : 'full' );
if ( self::validate_image_url( $src_per_wp[0] ) ) {
$src = $src_per_wp[0];
$fullsize_url = true;
// Prevent image distortion if a detected dimension exceeds the image's natural dimensions
if ( ( false !== $width && $width > $src_per_wp[1] ) || ( false !== $height && $height > $src_per_wp[2] ) ) {
$width = false == $width ? false : min( $width, $src_per_wp[1] );
$height = false == $height ? false : min( $height, $src_per_wp[2] );
}
// If no width and height are found, max out at source image's natural dimensions
// Otherwise, respect registered image sizes' cropping setting
if ( false == $width && false == $height ) {
$width = $src_per_wp[1];
$height = $src_per_wp[2];
$transform = 'fit';
} elseif ( isset( $size ) && array_key_exists( $size, $image_sizes ) && isset( $image_sizes[ $size ]['crop'] ) ) {
$transform = (bool) $image_sizes[ $size ]['crop'] ? 'resize' : 'fit';
}
}
} else {
unset( $attachment_id );
unset( $attachment );
}
}
}
// If image tag lacks width and height arguments, try to determine from strings WP appends to resized image filenames.
if ( false === $width && false === $height ) {
list( $width, $height ) = Jetpack_Photon::parse_dimensions_from_filename( $src );
}
// If width is available, constrain to $content_width
if ( false !== $width && false === strpos( $width, '%' ) && is_numeric( $content_width ) ) {
if ( $width > $content_width && false !== $height && false === strpos( $height, '%' ) ) {
$height = round( ( $content_width * $height ) / $width );
$width = $content_width;
} elseif ( $width > $content_width ) {
$width = $content_width;
}
}
// Set a width if none is found and $content_width is available
// If width is set in this manner and height is available, use `fit` instead of `resize` to prevent skewing
if ( false === $width && is_numeric( $content_width ) ) {
$width = (int) $content_width;
if ( false !== $height )
$transform = 'fit';
}
// Detect if image source is for a custom-cropped thumbnail and prevent further URL manipulation.
if ( ! $fullsize_url && preg_match_all( '#-e[a-z0-9]+(-\d+x\d+)?\.(' . implode('|', self::$extensions ) . '){1}$#i', basename( $src ), $filename ) )
$fullsize_url = true;
// Build URL, first removing WP's resized string so we pass the original image to Photon
if ( ! $fullsize_url && preg_match( '#(-\d+x\d+)\.(' . implode('|', self::$extensions ) . '){1}$#i', $src, $src_parts ) )
$src = str_replace( $src_parts[1], '', $src );
// Build array of Photon args and expose to filter before passing to Photon URL function
$args = array();
if ( false !== $width && false !== $height && false === strpos( $width, '%' ) && false === strpos( $height, '%' ) )
$args[ $transform ] = $width . ',' . $height;
elseif ( false !== $width )
$args['w'] = $width;
elseif ( false !== $height )
$args['h'] = $height;
$args = apply_filters( 'jetpack_photon_post_image_args', $args, compact( 'tag', 'src', 'src_orig', 'width', 'height' ) );
$photon_url = jetpack_photon_url( $src, $args );
// Modify image tag if Photon function provides a URL
// Ensure changes are only applied to the current image by copying and modifying the matched tag, then replacing the entire tag with our modified version.
if ( $src != $photon_url ) {
$new_tag = $tag;
// If present, replace the link href with a Photoned URL for the full-size image.
if ( ! empty( $images['link_url'][ $index ] ) && self::validate_image_url( $images['link_url'][ $index ] ) )
$new_tag = preg_replace( '#(href=["|\'])' . $images['link_url'][ $index ] . '(["|\'])#i', '\1' . jetpack_photon_url( $images['link_url'][ $index ] ) . '\2', $new_tag, 1 );
// Supplant the original source value with our Photon URL
$photon_url = esc_url( $photon_url );
$new_tag = str_replace( $src_orig, $photon_url, $new_tag );
// If Lazy Load is in use, pass placeholder image through Photon
if ( isset( $placeholder_src ) && self::validate_image_url( $placeholder_src ) ) {
$placeholder_src = jetpack_photon_url( $placeholder_src );
if ( $placeholder_src != $placeholder_src_orig )
$new_tag = str_replace( $placeholder_src_orig, esc_url( $placeholder_src ), $new_tag );
unset( $placeholder_src );
}
// Remove the width and height arguments from the tag to prevent distortion
$new_tag = preg_replace( '#(width|height)=["|\']?[\d%]+["|\']?\s?#i', '', $new_tag );
// Tag an image for dimension checking
$new_tag = preg_replace( '#(\s?/)?>(</a>)?$#i', ' data-recalc-dims="1"\1>\2', $new_tag );
// Replace original tag with modified version
$content = str_replace( $tag, $new_tag, $content );
}
} elseif ( preg_match( '#^http(s)?://i[\d]{1}.wp.com#', $src ) && ! empty( $images['link_url'][ $index ] ) && self::validate_image_url( $images['link_url'][ $index ] ) ) {
$new_tag = preg_replace( '#(href=["|\'])' . $images['link_url'][ $index ] . '(["|\'])#i', '\1' . jetpack_photon_url( $images['link_url'][ $index ] ) . '\2', $tag, 1 );
$content = str_replace( $tag, $new_tag, $content );
}
}
}
return $content;
}
/**
** CORE IMAGE RETRIEVAL
**/
/**
* Filter post thumbnail image retrieval, passing images through Photon
*
* @param string|bool $image
* @param int $attachment_id
* @param string|array $size
* @uses is_admin, apply_filters, wp_get_attachment_url, self::validate_image_url, this::image_sizes, jetpack_photon_url
* @filter image_downsize
* @return string|bool
*/
public function filter_image_downsize( $image, $attachment_id, $size ) {
// Don't foul up the admin side of things, and provide plugins a way of preventing Photon from being applied to images.
if ( is_admin() || apply_filters( 'jetpack_photon_override_image_downsize', false, compact( 'image', 'attachment_id', 'size' ) ) )
return $image;
// Get the image URL and proceed with Photon-ification if successful
$image_url = wp_get_attachment_url( $attachment_id );
if ( $image_url ) {
// Check if image URL should be used with Photon
if ( ! self::validate_image_url( $image_url ) )
return $image;
// If an image is requested with a size known to WordPress, use that size's settings with Photon
if ( ( is_string( $size ) || is_int( $size ) ) && array_key_exists( $size, self::image_sizes() ) ) {
$image_args = self::image_sizes();
$image_args = $image_args[ $size ];
$photon_args = array();
// `full` is a special case in WP
// To ensure filter receives consistent data regardless of requested size, `$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'] ) ) {
// 'crop' is true so Photon's `resize` method is used
$image_args = array(
'width' => $image_meta['width'],
'height' => $image_meta['height'],
'crop' => true
);
}
}
// Expose determined arguments to a filter before passing to Photon
$transform = $image_args['crop'] ? 'resize' : 'fit';
// Check specified image dimensions and account for possible zero values; photon fails to resize if a dimension is zero.
if ( 0 == $image_args['width'] || 0 == $image_args['height'] ) {
if ( 0 == $image_args['width'] && 0 < $image_args['height'] )
$photon_args['h'] = $image_args['height'];
elseif ( 0 == $image_args['height'] && 0 < $image_args['width'] )
$photon_args['w'] = $image_args['width'];
} else {
$photon_args[ $transform ] = $image_args['width'] . ',' . $image_args['height'];
}
$photon_args = apply_filters( 'jetpack_photon_image_downsize_string', $photon_args, compact( 'image_args', 'image_url', 'attachment_id', 'size', 'transform' ) );
// Generate Photon URL
$image = array(
jetpack_photon_url( $image_url, $photon_args ),
false,
false
);
} elseif ( is_array( $size ) ) {
// Pull width and height values from the provided array, if possible
$width = isset( $size[0] ) ? (int) $size[0] : false;
$height = isset( $size[1] ) ? (int) $size[1] : false;
// Don't bother if necessary parameters aren't passed.
if ( ! $width || ! $height )
return $image;
// Expose arguments to a filter before passing to Photon
$photon_args = array(
'fit' => $width . ',' . $height
);
$photon_args = apply_filters( 'jetpack_photon_image_downsize_array', $photon_args, compact( 'width', 'height', 'image_url', 'attachment_id' ) );
// Generate Photon URL
$image = array(
jetpack_photon_url( $image_url, $photon_args ),
false,
false
);
}
}
return $image;
}
/**
** GENERAL FUNCTIONS
**/
/**
* Ensure image URL is valid for Photon.
* Though Photon functions address some of the URL issues, we should avoid unnecessary processing if we know early on that the image isn't supported.
*
* @param string $url
* @uses wp_parse_args
* @return bool
*/
protected static function validate_image_url( $url ) {
$parsed_url = @parse_url( $url );
if ( ! $parsed_url )
return false;
// Parse URL and ensure needed keys exist, since the array returned by `parse_url` only includes the URL components it finds.
$url_info = wp_parse_args( $parsed_url, array(
'scheme' => null,
'host' => null,
'port' => null,
'path' => null
) );
// Bail if scheme isn't http or port is set that isn't port 80
if ( ( 'http' != $url_info['scheme'] || ! in_array( $url_info['port'], array( 80, null ) ) ) && apply_filters( 'jetpack_photon_reject_https', true ) )
return false;
// Bail if no host is found
if ( is_null( $url_info['host'] ) )
return false;
// Bail if the image alredy went through Photon
if ( preg_match( '#^i[\d]{1}.wp.com$#i', $url_info['host'] ) )
return false;
// Bail if no path is found
if ( is_null( $url_info['path'] ) )
return false;
// Ensure image extension is acceptable
if ( ! in_array( strtolower( pathinfo( $url_info['path'], PATHINFO_EXTENSION ) ), self::$extensions ) )
return false;
// If we got this far, we should have an acceptable image URL
return true;
}
/**
* 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 $wp_additional_image_sizes
* @uses get_option
* @return array
*/
protected static function image_sizes() {
if ( null == self::$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(
'thumb' => 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
)
);
// Compatibility mapping as found in wp-includes/media.php
$images['thumbnail'] = $images['thumb'];
// Update class variable, merging in $_wp_additional_image_sizes if any are set
if ( is_array( $_wp_additional_image_sizes ) && ! empty( $_wp_additional_image_sizes ) )
self::$image_sizes = array_merge( $images, $_wp_additional_image_sizes );
else
self::$image_sizes = $images;
}
return is_array( self::$image_sizes ) ? self::$image_sizes : array();
}
/**
* Pass og:image URLs through Photon
*
* @param array $tags
* @param array $parameters
* @uses jetpack_photon_url
* @return array
*/
function filter_open_graph_tags( $tags, $parameters ) {
if ( empty( $tags['og:image'] ) ) {
return $tags;
}
$photon_args = array(
'fit' => sprintf( '%d,%d', 2 * $parameters['image_width'], 2 * $parameters['image_height'] ),
);
if ( is_array( $tags['og:image'] ) ) {
$images = array();
foreach ( $tags['og:image'] as $image ) {
$images[] = jetpack_photon_url( $image, $photon_args );
}
$tags['og:image'] = $images;
} else {
$tags['og:image'] = jetpack_photon_url( $tags['og:image'], $photon_args );
}
return $tags;
}
/**
* Enqueue Photon helper script
*
* @uses wp_enqueue_script, plugins_url
* @action wp_enqueue_script
* @return null
*/
public function action_wp_enqueue_scripts() {
wp_enqueue_script( 'jetpack-photon', plugins_url( 'modules/photon/photon.js', __FILE__ ), array( 'jquery' ), 20130122, true );
}
}