external-media-without-import.php

<?php
/*
Plugin Name: External Media without Import
Description: Add external images to the media library without importing, i.e. uploading them to your WordPress site.
Version: 1.0.1
Author: Zhixiang Zhu
Author URI: http://zxtechart.com
License: GPLv3
License URI: https://www.gnu.org/licenses/gpl-3.0-standalone.html

External Media without Import 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 any later version.
 
External Media without Import 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 External Media without Import. If not, see
https://www.gnu.org/licenses/gpl-3.0-standalone.html.
*/
namespace emwi;

$style = 'emwi-css';
$css_file = plugins_url( '/external-media-without-import.css', __FILE__ );
wp_register_style( $style, $css_file );
wp_enqueue_style( $style );

$script = 'emwi-js';
$js_file = plugins_url( '/external-media-without-import.js', __FILE__ );
wp_register_script( $script, $js_file, array( 'jquery' ) );
wp_enqueue_script( $script );

add_action( 'admin_menu', 'emwi\add_submenu' );
add_action( 'post-plupload-upload-ui', 'emwi\post_upload_ui' );
add_action( 'post-html-upload-ui', 'emwi\post_upload_ui' );
add_action( 'wp_ajax_add_external_media_without_import', 'emwi\wp_ajax_add_external_media_without_import' );
add_action( 'admin_post_add_external_media_without_import', 'emwi\admin_post_add_external_media_without_import' );

function add_submenu() {
	add_submenu_page(
		'upload.php',
		__( 'Add External Media without Import' ),
		__( 'Add External Media without Import' ),
		'manage_options',
		'add-external-media-without-import',
		'emwi\print_submenu_page'
	);
}

function post_upload_ui() {
	$media_library_mode = get_user_option( 'media_library_mode', get_current_user_id() );
?>
	<div id="emwi-in-upload-ui">
	  <div class="row1">
		<?php echo __('or'); ?>
	  </div>
	  <div class="row2">
		<?php if ( 'grid' === $media_library_mode ) : ?>
		  <button id="emwi-show" class="button button-large">
			<?php echo __('Add External Media without Import'); ?>
		  </button>
		  <?php print_media_new_panel( true ); ?>
		<?php else : ?>
		  <a class="button button-large" href="<?php echo esc_url( admin_url( '/upload.php?page=add-external-media-without-import', __FILE__ ) ); ?>">
			<?php echo __('Add External Media without Import'); ?>
		  </a>
		<?php endif; ?>
	  </div>
	</div>
<?php
}

function print_submenu_page() {
?>
	<form action="<?php echo esc_url( admin_url('admin-post.php') ); ?>" method="post">
	  <?php print_media_new_panel( false ); ?>
	</form>
<?php
}

function print_media_new_panel( $is_in_upload_ui ) {
?>
	<div id="emwi-media-new-panel" <?php if ( $is_in_upload_ui  ) : ?>style="display: none"<?php endif; ?>>
	  <div class="url-row">
		<label><?php echo __('Add a media from URL'); ?></label>
		<span id="emwi-url-input-wrapper">
		  <input id="emwi-url" name="url" type="url" required placeholder="<?php echo __('Image URL');?>" value="<?php echo esc_url( $_GET['url'] ); ?>">
		</span>
	  </div>
	  <div id="emwi-hidden" <?php if ( $is_in_upload_ui || empty( $_GET['error'] ) ) : ?>style="display: none"<?php endif; ?>>
		<div>
		  <span id="emwi-error"><?php echo esc_html( $_GET['error'] ); ?></span>
		  <?php echo _('Please fill in the following properties manually. If you leave the fields blank (or 0 for width/height), the plugin will try to resolve them automatically'); ?>
		</div>
		<div id="emwi-properties">
		  <label><?php echo __('Width'); ?></label>
		  <input id="emwi-width" name="width" type="number" value="<?php echo esc_html( $_GET['width'] ); ?>">
		  <label><?php echo __('Height'); ?></label>
		  <input id="emwi-height" name="height" type="number" value="<?php echo esc_html( $_GET['height'] ); ?>">
		  <label><?php echo __('MIME Type'); ?></label>
		  <input id="emwi-mime-type" name="mime-type" type="text" value="<?php echo esc_html( $_GET['mime-type'] ); ?>">
		</div>
	  </div>
	  <div id="emwi-buttons-row">
		<input type="hidden" name="action" value="add_external_media_without_import">
		<span class="spinner"></span>
		<input type="button" id="emwi-clear" class="button" value="<?php echo __('Clear') ?>">
		<input type="submit" id="emwi-add" class="button button-primary" value="<?php echo __('Add') ?>">
		<?php if ( $is_in_upload_ui  ) : ?>
		  <input type="button" id="emwi-cancel" class="button" value="<?php echo __('Cancel') ?>">
		<?php endif; ?>
	  </div>
	</div>
<?php
}

function wp_ajax_add_external_media_without_import() {
	$info = add_external_media_without_import();
	if ( isset( $info['id'] ) ) {
		if ( $attachment = wp_prepare_attachment_for_js( $info['id'] ) ) {
			wp_send_json_success( $attachment );
		}
		else {
			$info['error'] = _('Failed to prepare attachment for js');
			wp_send_json_error( $info );
		}
	}
	else {
		wp_send_json_error( $info );
	}
}

function admin_post_add_external_media_without_import() {
	$info = add_external_media_without_import();
	$redirect_url = 'upload.php';
	if ( ! isset( $info['id'] ) ) {
		$redirect_url = $redirect_url .  '?page=add-external-media-without-import&url=' . urlencode( $info['url'] );
		$redirect_url = $redirect_url . '&error=' . urlencode( $info['error'] );
		$redirect_url = $redirect_url . '&width=' . urlencode( $info['width'] );
		$redirect_url = $redirect_url . '&height=' . urlencode( $info['height'] );
		$redirect_url = $redirect_url . '&mime-type=' . urlencode( $info['mime-type'] );
	}
	wp_redirect( admin_url( $redirect_url ) );
	exit;
}

function sanitize_and_validate_input() {
	// Don't call sanitize_text_field on url because it removes '%20'.
	// Always use esc_url/esc_url_raw when sanitizing URLs. See:
	// https://codex.wordpress.org/Function_Reference/esc_url
	$input = array(
		'url' => esc_url_raw( $_POST['url'] ),
		'width' => sanitize_text_field( $_POST['width'] ),
		'height' => sanitize_text_field( $_POST['height'] ),
		'mime-type' => sanitize_mime_type( $_POST['mime-type'] )
	);

	$width_str = $input['width'];
	$width_int = intval( $width_str );
	if ( ! empty( $width_str ) && $width_int <= 0 ) {
		$input['error'] = _('Width and height must be non-negative integers.');
		return $input;
	}

	$height_str = $input['height'];
	$height_int = intval( $height_str );
	if ( ! empty( $height_str ) && $height_int <= 0 ) {
		$input['error'] = _('Width and height must be non-negative integers.');
		return $input;
	}

	$input['width'] = $width_int;
	$input['height'] = $height_int;

	return $input;
}

function add_external_media_without_import() {
	$input = sanitize_and_validate_input();

	if ( isset( $input['error'] ) ) {
		return $input;
	}

	$url = $input['url'];
	$width = $input['width'];
	$height = $input['height'];
	$mime_type = $input['mime-type'];

	if ( empty( $width ) || empty( $height ) || empty( $mime_type ) ) {
		$image_size = @getimagesize( $url );

		if ( empty( $image_size ) ) {
			if ( empty( $mime_type ) ) {
				$response = wp_remote_head( $url );
				if ( is_array( $response ) && isset( $response['headers']['content-type'] ) ) {
					$input['mime-type'] = $response['headers']['content-type'];
				}
			}
			$input['error'] = _('Unable to get the image size.');
			return $input;
		}

		if ( empty( $width ) ) {
			$width = $image_size[0];
		}

		if ( empty( $height ) ) {
			$height = $image_size[1];
		}

		if ( empty( $mime_type ) ) {
			$mime_type = $image_size['mime'];
		}
	}

	$filename = wp_basename( $url );
	$attachment = array(
		'guid' => $url,
		'post_mime_type' => $mime_type,
		'post_title' => preg_replace( '/\.[^.]+$/', '', $filename ),
	);
	$attachment_metadata = array( 'width' => $width, 'height' => $height, 'file' => $filename );
	$attachment_metadata['sizes'] = array( 'full' => $attachment_metadata );
	$attachment_id = wp_insert_attachment( $attachment );
	wp_update_attachment_metadata( $attachment_id, $attachment_metadata );

	$input['id'] = $attachment_id;
	return $input;
}