WordPress函数wp_prepare_attachment_for_js()用法 获取附件JSON序列信息

描述：

获取一个附件(图片/文件)的JSON序列信息

用法：

<?php wp_prepare_attachment_for_js( $attachment ) ?>

参数：

$attachment

(mixed) (必填) 附件ID或对象

默认值: None

示例：

<?php
add_action( 'wp_head', 'my_js_gallery_add_gallery_images', 1 );
function my_js_gallery_add_gallery_images(){
global $post;

$gallery_images = array();
$attachments = get_posts( array(
'post_type' => 'attachment',
'post_status' => 'inherit',
'post_parent' => $post->ID,
'post_mime_type' => 'image',
) );

foreach( $attachments as $attachment )
$gallery_images[] = wp_prepare_attachment_for_js( $attachment->ID );

wp_localize_script( 'my-js-gallery', 'my_js_gallery', array(
'images' => $gallery_images,
) );
}

源文件：

/**
* 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 );
}