WordPress/wp-includes/feed-rssjs-comments.php

<?php
/**
 * rss.js Feed Template for displaying rss.js Comments feed.
 *
 * @package WordPress
 * @subpackage Feed
 * @since 3.8.0
 */

$json = new stdClass();
$json->rss = new stdClass();

$json->rss->version = "2.0";
$json->rss->channel = new stdClass();

if ( is_singular() )
	$json->rss->channel->title = sprintf( __( 'Comments on: %s' ), get_the_title() );
elseif ( is_search() )
	$json->rss->channel->title = sprintf( __( 'Comments for %1$s searching on %2$s' ), get_bloginfo( 'name' ), get_search_query() );
else
	$json->rss->channel->title = sprintf( __( 'Comments for %s' ), get_bloginfo( 'name' ) . get_the_title() );

$json->rss->channel->link          = get_bloginfo( 'url' );
$json->rss->channel->description   = get_bloginfo( 'description' );
$json->rss->channel->language      = get_bloginfo( 'language' );
$json->rss->channel->lastBuildDate = mysql2date( 'D, d M Y H:i:s +0000', get_lastcommentmodified( 'GMT' ), false );
$json->rss->channel->docs          = "http://cyber.law.harvard.edu/rss/rss.html";
$json->rss->channel->generator     = 'WordPress ' . get_bloginfo( 'version' );
$json->rss->channel->ttl           = 15;

$json->rss->channel->item = array();

header( 'Content-Type: ' . feed_content_type( 'rssjs' ) . '; charset=' . get_option( 'blog_charset' ), true );

/*
 * The JSONP callback function to add to the JSON feed
 *
 * @since 3.8.0
 *
 * @param string $callback The JSONP callback function name
 */
$callback = apply_filters( 'json_feed_callback', get_query_var( 'callback' ) );

if ( ! empty( $callback ) && ! apply_filters( 'json_jsonp_enabled', true ) ) {
	status_header( 400 );
	echo json_encode( array(
		'code'    => 'json_callback_disabled',
		'message' => 'JSONP support is disabled on this site.'
	) );
	exit;
}

if ( preg_match( '/\W/', $callback ) ) {
	status_header( 400 );
	echo json_encode( array(
		'code'    => 'json_callback_invalid',
		'message' => 'The JSONP callback function is invalid.'
	) );
	exit;
}

/*
 * Action triggered prior to the JSON feed being created and sent to the client
 *
 * @since 3.8.0
 */
do_action( 'json_feed_pre' );

while( have_comments() ) {
	the_comment();

	$comment_post = $GLOBALS['post'] = get_post( $comment->comment_post_ID );

	$item = new stdClass();

	if ( !is_singular() ) {
		$title = get_the_title( $comment_post->ID );
		$item->title = sprintf( __('Comment on %1$s by %2$s') , $title, get_comment_author() );
	} else {
		$item->title = sprintf( __('By: %s'), get_comment_author() );
	}

	$item->link    = get_comment_link();
	$item->guid    = get_comment_guid();
	$item->pubDate = mysql2date( 'D, d M Y H:i:s +0000', get_post_time( 'Y-m-d H:i:s', true ), false );

	if ( post_password_required( $comment_post ) ) {
		$item->description = __( 'Protected Comments: Please enter your password to view comments.' );
	} else {
		$item->description = get_comment_text();
	}

	/*
	 * The item to be added to the rss.js Comment feed
	 *
	 * @since 3.8.0
	 *
	 * @param object $item The rss.js Comment item
	 */
	$item = apply_filters( 'comment_rssjs_feed_item', $item );

	$json->rss->channel->item[] = $item;
}

/*
 * The data to be sent to the user as JSON
 *
 * @since 3.8.0
 *
 * @param object $json The JSON data object
 */
$json = apply_filters( 'comment_rssjs_feed', $json );

$json_str = json_encode( $json );

if ( ! empty( $callback ) ) {
	echo "$callback( $json_str );";
} else {
	echo $json_str;
}

/*
 * Action triggered after the JSON feed has been created and sent to the client
 *
 * @since 3.8.0
 */
do_action( 'json_feed_post' );