wp_prepare_attachment_for_js( int|WP_Post $attachment )

为JS准备一个attachment post对象，该对象应该是JSON编码的并适合于附件模型。
Prepares an attachment post object for JS, where it is expected to be JSON-encoded and fit into an Attachment model.

参数（Parameters）

源码（Source）

/**
 * Prepares an attachment post object for JS, where it is expected
 * to be JSON-encoded and fit into an Attachment model.
 *
 * @since 3.5.0
 *
 * @param mixed $attachment Attachment ID or object.
 * @return array|void Array of attachment details.
 */
function wp_prepare_attachment_for_js( $attachment ) {
	if ( ! $attachment = get_post( $attachment ) )
		return;

	if ( 'attachment' != $attachment->post_type )
		return;

	$meta = wp_get_attachment_metadata( $attachment->ID );
	if ( false !== strpos( $attachment->post_mime_type, '/' ) )
		list( $type, $subtype ) = explode( '/', $attachment->post_mime_type );
	else
		list( $type, $subtype ) = array( $attachment->post_mime_type, '' );

	$attachment_url = wp_get_attachment_url( $attachment->ID );

	$response = array(
		'id'          => $attachment->ID,
		'title'       => $attachment->post_title,
		'filename'    => wp_basename( get_attached_file( $attachment->ID ) ),
		'url'         => $attachment_url,
		'link'        => get_attachment_link( $attachment->ID ),
		'alt'         => get_post_meta( $attachment->ID, '_wp_attachment_image_alt', true ),
		'author'      => $attachment->post_author,
		'description' => $attachment->post_content,
		'caption'     => $attachment->post_excerpt,
		'name'        => $attachment->post_name,
		'status'      => $attachment->post_status,
		'uploadedTo'  => $attachment->post_parent,
		'date'        => strtotime( $attachment->post_date_gmt ) * 1000,
		'modified'    => strtotime( $attachment->post_modified_gmt ) * 1000,
		'menuOrder'   => $attachment->menu_order,
		'mime'        => $attachment->post_mime_type,
		'type'        => $type,
		'subtype'     => $subtype,
		'icon'        => wp_mime_type_icon( $attachment->ID ),
		'dateFormatted' => mysql2date( get_option('date_format'), $attachment->post_date ),
		'nonces'      => array(
			'update' => false,
			'delete' => false,
			'edit'   => false
		),
		'editLink'   => false,
		'meta'       => false,
	);

	$author = new WP_User( $attachment->post_author );
	$response['authorName'] = $author->display_name;

	if ( $attachment->post_parent ) {
		$post_parent = get_post( $attachment->post_parent );
	} else {
		$post_parent = false;
	}

	if ( $post_parent ) {
		$parent_type = get_post_type_object( $post_parent->post_type );
		if ( $parent_type && $parent_type->show_ui && current_user_can( 'edit_post', $attachment->post_parent ) ) {
			$response['uploadedToLink'] = get_edit_post_link( $attachment->post_parent, 'raw' );
		}
		$response['uploadedToTitle'] = $post_parent->post_title ? $post_parent->post_title : __( '(no title)' );
	}

	$attached_file = get_attached_file( $attachment->ID );
	if ( file_exists( $attached_file ) ) {
		$bytes = filesize( $attached_file );
		$response['filesizeInBytes'] = $bytes;
		$response['filesizeHumanReadable'] = size_format( $bytes );
	}

	if ( current_user_can( 'edit_post', $attachment->ID ) ) {
		$response['nonces']['update'] = wp_create_nonce( 'update-post_' . $attachment->ID );
		$response['nonces']['edit'] = wp_create_nonce( 'image_editor-' . $attachment->ID );
		$response['editLink'] = get_edit_post_link( $attachment->ID, 'raw' );
	}

	if ( current_user_can( 'delete_post', $attachment->ID ) )
		$response['nonces']['delete'] = wp_create_nonce( 'delete-post_' . $attachment->ID );

	if ( $meta && 'image' === $type ) {
		$sizes = array();

		/** This filter is documented in wp-admin/includes/media.php */
		$possible_sizes = apply_filters( 'image_size_names_choose', array(
			'thumbnail' => __('Thumbnail'),
			'medium'    => __('Medium'),
			'large'     => __('Large'),
			'full'      => __('Full Size'),
		) );
		unset( $possible_sizes['full'] );

		// Loop through all potential sizes that may be chosen. Try to do this with some efficiency.
		// First: run the image_downsize filter. If it returns something, we can use its data.
		// If the filter does not return something, then image_downsize() is just an expensive
		// way to check the image metadata, which we do second.
		foreach ( $possible_sizes as $size => $label ) {

			/** This filter is documented in wp-includes/media.php */
			if ( $downsize = apply_filters( 'image_downsize', false, $attachment->ID, $size ) ) {
				if ( ! $downsize[3] )
					continue;
				$sizes[ $size ] = array(
					'height'      => $downsize[2],
					'width'       => $downsize[1],
					'url'         => $downsize[0],
					'orientation' => $downsize[2] > $downsize[1] ? 'portrait' : 'landscape',
				);
			} elseif ( isset( $meta['sizes'][ $size ] ) ) {
				if ( ! isset( $base_url ) )
					$base_url = str_replace( wp_basename( $attachment_url ), '', $attachment_url );

				// Nothing from the filter, so consult image metadata if we have it.
				$size_meta = $meta['sizes'][ $size ];

				// We have the actual image size, but might need to further constrain it if content_width is narrower.
				// Thumbnail, medium, and full sizes are also checked against the site's height/width options.
				list( $width, $height ) = image_constrain_size_for_editor( $size_meta['width'], $size_meta['height'], $size, 'edit' );

				$sizes[ $size ] = array(
					'height'      => $height,
					'width'       => $width,
					'url'         => $base_url . $size_meta['file'],
					'orientation' => $height > $width ? 'portrait' : 'landscape',
				);
			}
		}

		$sizes['full'] = array( 'url' => $attachment_url );

		if ( isset( $meta['height'], $meta['width'] ) ) {
			$sizes['full']['height'] = $meta['height'];
			$sizes['full']['width'] = $meta['width'];
			$sizes['full']['orientation'] = $meta['height'] > $meta['width'] ? 'portrait' : 'landscape';
		}

		$response = array_merge( $response, array( 'sizes' => $sizes ), $sizes['full'] );
	} elseif ( $meta && 'video' === $type ) {
		if ( isset( $meta['width'] ) )
			$response['width'] = (int) $meta['width'];
		if ( isset( $meta['height'] ) )
			$response['height'] = (int) $meta['height'];
	}

	if ( $meta && ( 'audio' === $type || 'video' === $type ) ) {
		if ( isset( $meta['length_formatted'] ) )
			$response['fileLength'] = $meta['length_formatted'];

		$response['meta'] = array();
		foreach ( wp_get_attachment_id3_keys( $attachment, 'js' ) as $key => $label ) {
			$response['meta'][ $key ] = false;

			if ( ! empty( $meta[ $key ] ) ) {
				$response['meta'][ $key ] = $meta[ $key ];
			}
		}

		$id = get_post_thumbnail_id( $attachment->ID );
		if ( ! empty( $id ) ) {
			list( $src, $width, $height ) = wp_get_attachment_image_src( $id, 'full' );
			$response['image'] = compact( 'src', 'width', 'height' );
			list( $src, $width, $height ) = wp_get_attachment_image_src( $id, 'thumbnail' );
			$response['thumb'] = compact( 'src', 'width', 'height' );
		} else {
			$src = wp_mime_type_icon( $attachment->ID );
			$width = 48;
			$height = 64;
			$response['image'] = compact( 'src', 'width', 'height' );
			$response['thumb'] = compact( 'src', 'width', 'height' );
		}
	}

	if ( function_exists('get_compat_media_markup') )
		$response['compat'] = get_compat_media_markup( $attachment->ID, array( 'in_modal' => true ) );

	/**
	 * Filter the attachment data prepared for JavaScript.
	 *
	 * @since 3.5.0
	 *
	 * @param array      $response   Array of prepared attachment data.
	 * @param int|object $attachment Attachment ID or object.
	 * @param array      $meta       Array of attachment meta data.
	 */
	return apply_filters( 'wp_prepare_attachment_for_js', $response, $attachment, $meta );
}

笔记（Notes）