gistfile1.php

<?php

/**
 * WP1
 * To Dos
 *
 * * sending comments needs to add current author data along with the comment data and thus register authorA ? on B along with the comment ?
 * * send comment to a post on B from a post on A
 * * send comment to a post on B from a comment on a post on A
 * * parse url in post / comment
 * * handle response from B @A so as to notify authorA
 */
/*
  Plugin Name: Ping
  Description: Attempting to do this http://activitypingback.org/
  Author: Jigar Vyas
  Version: 1.0
 */

require "/var/www/html/library/curl.php";

add_action("publish_post", "send");

if (!empty($_POST)) {
    add_action("the_posts", "get");
}

function get($post) {
    return add_comment(array("post_id" => $post[0]->ID, "comment" => $_POST['comment']));
    exit;
}

function add_comment($comment_data) {
    $commentdata['comment_post_ID'] = $comment_data['post_id'];
    $commentdata['comment_content'] = $comment_data['comment'];

    return wp_new_comment($commentdata);
}

function send($post_id) {
    $_post_data = get_post($post_id);

    $_urls = _parse_for_urls($_post_data->post_content);

    if ($_urls) {
        $curl = new Curl();
        foreach ($_urls as $_url) {
            $params['url'] = $_url;
            $comment = "MY 2 cents:<br>";
            $params['fields_data'] = array("comment" => $comment . $_post_data->post_content);
            $curl->post($params);
        }
    }

    return false;
}

function _parse_for_urls($str) {
    $to_return = array("http://localhost/wp2/?p=1");

    return $to_return;
}

?>

BTW does Wordpress have its own http client? If yes, then you could use that so don't have to bundle the curl.php dependency.

• the exit was during testing when I was sending a normal form post from a local link to a blog and that get would load the WP Blog header before getting $_POST data. Not reqd now
• haven't looked for a client within WP itself. Got to check. Will update