[WordPress] Attachment image to base64

class-attachment-image-to-base64.php

<?php
/**
 * Attachment image to base64
 *
 * @package    WordPress
 * @subpackage VA Attachment image to base64
 * @author     KUCKLU <kuck1u@visualive.jp>
 *             Copyright (C) 2015  KUCKLU and VisuAlive.
 *             This program is free software: you can redistribute it and/or modify
 *             it under the terms of the GNU General Public License as published by
 *             the Free Software Foundation, either version 3 of the License, or
 *             (at your option) any later version.
 *             This program is distributed in the hope that it will be useful,
 *             but WITHOUT ANY WARRANTY; without even the implied warranty of
 *             MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *             GNU General Public License for more details.
 *             You should have received a copy of the GNU General Public License
 *             along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

class VisuAlive_AttachmentImage_To_Base64 {
    /**
     * Get instance.
     *
     * @since VisuAlive 1.0.0
     * @return VisuAlive_AttachmentImage_To_Base64
     */
    public static function init() {
        static $instance = false;

        if ( ! $instance ) {
            $instance = new VisuAlive_AttachmentImage_To_Base64;
        }

        return $instance;
    }

    public function __construct() {
        add_filter( 'wp_update_attachment_metadata', [ &$this, 'wp_update_attachment_metadata' ], 10, 2 );
        add_filter( 'image_downsize', [ &$this, 'image_downsize' ], 10, 3 );
        add_filter( 'wp_calculate_image_srcset_meta', [ &$this, 'wp_calculate_image_srcset_meta' ], 10, 4 );
        add_filter( 'wp_calculate_image_srcset', [ &$this, 'wp_calculate_image_srcset' ], 10, 5 );
        add_filter( 'tiny_mce_before_init', [ &$this, 'tiny_mce_enable_base64_images' ] );
    }

    /**
     * Change attachment metadata.
     *
     * @param array $data Array of updated attachment meta data.
     *
     * @return array
     */
    public function wp_update_attachment_metadata( $data = [ ], $post_ID ) {
        $mime_types = self::_image_mime_types();
        $file_type  = isset( $data['file'] ) ? self::_check_filetype( $data['file'] ) : null;
        $post_meta  = $data;

        if ( ! is_null( $file_type ) && in_array( $file_type, $mime_types ) ) {
            $upload_dir        = wp_upload_dir();
            $img_path_original = $upload_dir['basedir'] . DIRECTORY_SEPARATOR . $post_meta['file'];

            if ( file_exists( $img_path_original ) ) {
                $base64_original = self::_image_to_base64( $img_path_original, $file_type );

                if ( ! is_null( $base64_original ) ) {
                    $post_meta['file'] = $base64_original;
                }

                foreach ( $post_meta['sizes'] as $size => $value ) {
                    $img_path_child = $upload_dir['path'] . DIRECTORY_SEPARATOR . $value['file'];

                    if ( file_exists( $img_path_child ) ) {
                        $base64_child = self::_image_to_base64( $img_path_child, $value['mime-type'] );

                        if ( ! is_null( $base64_child ) ) {
                            $post_meta['sizes'][ $size ]['file'] = $base64_child;
                        }
                    }
                }
            }
        }

        update_post_meta( $post_ID, '_va_attachment_image_to_base64', $post_meta );

        return $data;
    }

    /**
     * Change attachment data.
     *
     * @param bool         $file
     * @param int          $id
     * @param string|array $size
     *
     * @return array
     */
    public function image_downsize( $file, $id, $size ) {
        $metas        = self::_get_attachment_metadata( $id );
        $site_icon_id = get_option( 'site_icon' );

        if ( ! isset( $metas, $metas['sizes'] ) || empty( $metas ) || (int) $site_icon_id === (int) $id ) {
            return $file;
        }

        if ( isset( $metas['sizes'][ $size ] ) ) {
            $check = self::_confirm_an_image_is_base64( $metas['sizes'][ $size ]['file'] );

            if ( $check ) {
                $file = [
                    $metas['sizes'][ $size ]['file'],
                    $metas['sizes'][ $size ]['width'],
                    $metas['sizes'][ $size ]['height'],
                    true,
                ];
            }
        } else {
            $check = self::_confirm_an_image_is_base64( $metas['file'] );

            if ( $check ) {
                $file = [
                    $metas['file'],
                    $metas['width'],
                    $metas['height'],
                    true,
                ];
            }
        }

        return $file;
    }

    public function wp_calculate_image_srcset_meta( $image_meta, $size_array, $image_src, $attachment_id ) {
        return self::_get_attachment_metadata( $attachment_id );
    }

    /**
     * Filter an image's 'srcset' sources.
     *
     * @param array  $sources
     * @param array  $size_array    Array of width and height values in pixels (in that order).
     * @param string $image_src     The 'src' of the image.
     * @param array  $image_meta    The image meta data as returned by 'wp_get_attachment_metadata()'.
     * @param int    $attachment_id Image attachment ID or 0.
     *
     * @return array
     */
    public function wp_calculate_image_srcset( $sources, $size_array, $image_src, $image_meta, $attachment_id ) {
        $upload_dir = wp_upload_dir();

        if ( is_array( $sources ) && ! empty( $sources ) ) {
            foreach ( $sources as $key => $value ) {
                $sources[ $key ]['url'] = str_replace( trailingslashit( $upload_dir['baseurl'] ), '', $value['url'] );
            }
        }

        return $sources;
    }

    /**
     * [TinyMCE] Enable base64 images.
     *
     * @param array $settings
     *
     * @return array
     */
    public function tiny_mce_enable_base64_images( $settings ) {
        $settings['paste_data_images'] = true;

        return $settings;
    }

    /**
     * Confirm an image is base64.
     *
     * @param string $file
     *
     * @return bool
     */
    protected function _confirm_an_image_is_base64( $file = '' ) {
        return (bool) preg_match( '/(data:(image\/jpeg|image\/png|image\/gif|image\/bmp);base64,)/i', $file );
    }

    /**
     * Mime types.
     *
     * @return array
     */
    protected function _image_mime_types() {
        return [ 'image/jpeg', 'image/png', 'image/gif', 'image/bmp' ];
    }

    /**
     * Check file type.
     *
     * @param string $file
     *
     * @return string
     */
    protected function _check_filetype( $file = '' ) {
        $file = wp_check_filetype( $file, wp_get_mime_types() );

        return $file['type'];
    }

    /**
     * Retrieve attachment meta field for attachment ID.
     *
     * @param int  $post_id    Attachment ID. Default 0.
     * @param bool $unfiltered Optional. If true, filters are not run. Default false.
     *
     * @return mixed Attachment meta field. False on failure.
     */
    protected function _get_attachment_metadata( $post_id = 0, $unfiltered = false ) {
        $post_id = (int) $post_id;

        if ( ! $post = get_post( $post_id ) ) {
            return false;
        }

        $data = get_post_meta( $post->ID, '_va_attachment_image_to_base64', true );

        if ( $unfiltered ) {
            return $data;
        }

        /**
         * Filter the attachment meta data.
         *
         * @param array|bool $data    Array of meta data for the given attachment, or false
         *                            if the object does not exist.
         * @param int        $post_id Attachment ID.
         */

        return apply_filters( 'va_get_attachment_metadata', $data, $post->ID );
    }

    /**
     * Image to base64.
     *
     * @param string $image_path
     * @param string $mime_type
     *
     * @return null|string
     */
    protected function _image_to_base64( $image_path = '', $mime_type = '' ) {
        $result     = null;
        $mime_types = self::_image_mime_types();

        if ( file_exists( $image_path ) && in_array( $mime_type, $mime_types ) ) {
            $result = base64_encode( file_get_contents( $image_path ) );
            $result = 'data:' . $mime_type . ';base64,' . $result;
        }

        return $result;
    }
}

現在確認出来ている不具合

• カスタムヘッダーの URL がテーマオプションに保存されない
• サイトアイコンの URL が出力されない

不具合ではなく仕様

• カスタムヘッダーの URL は Data URI にはならない。

やればやるほどハマる orz
wp_update_attachment_metadata で書き換えないで、素直に meta data として別途保存した方が幸せになれそう。

なんとか形になった。