ci-bonfire / Sprint

system/libraries/Trackback.php

<?php

For compatibility and reusability of your code, PSR1 recommends that a file should introduce either new symbols (like classes, functions, etc.) or have side-effects (like outputting something, or including other files), but not both at the same time. The first symbol is defined on line 51 and the first side effect is on line 38.

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	http://codeigniter.com
 * @since	Version 1.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Trackback Class
 *
 * Trackback Sending/Receiving Class
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Trackbacks
 * @author		EllisLab Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/trackback.html
 */
class CI_Trackback {

	/**
	 * Character set
	 *
	 * @var	string
	 */
	public $charset = 'UTF-8';

	/**
	 * Trackback data
	 *
	 * @var	array
	 */
	public $data = array(
		'url' => '',
		'title' => '',
		'excerpt' => '',
		'blog_name' => '',
		'charset' => ''
	);

	/**
	 * Convert ASCII flag
	 *
	 * Whether to convert high-ASCII and MS Word
	 * characters to HTML entities.
	 *
	 * @var	bool
	 */
	public $convert_ascii = TRUE;

	/**
	 * Response
	 *
	 * @var	string
	 */
	public $response = '';

	/**
	 * Error messages list
	 *
	 * @var	string[]
	 */
	public $error_msg = array();

	// --------------------------------------------------------------------

	/**
	 * Constructor
	 *
	 * @return	void
	 */
	public function __construct()
	{
		log_message('info', 'Trackback Class Initialized');
	}

	// --------------------------------------------------------------------

	/**
	 * Send Trackback
	 *
	 * @param	array
	 * @return	bool
	 */
	public function send($tb_data)
	{
		if ( ! is_array($tb_data))
		{
			$this->set_error('The send() method must be passed an array');
			return FALSE;
		}

		// Pre-process the Trackback Data
		foreach (array('url', 'title', 'excerpt', 'blog_name', 'ping_url') as $item)
		{
			if ( ! isset($tb_data[$item]))
			{
				$this->set_error('Required item missing: '.$item);
				return FALSE;
			}

			switch ($item)
			{
				case 'ping_url':
					$$item = $this->extract_urls($tb_data[$item]);
					break;
				case 'excerpt':
					$$item = $this->limit_characters($this->convert_xml(strip_tags(stripslashes($tb_data[$item]))));
					break;
				case 'url':
					$$item = str_replace('-', '-', $this->convert_xml(strip_tags(stripslashes($tb_data[$item]))));
					break;
				default:
					$$item = $this->convert_xml(strip_tags(stripslashes($tb_data[$item])));
					break;
			}

			// Convert High ASCII Characters
			if ($this->convert_ascii === TRUE && in_array($item, array('excerpt', 'title', 'blog_name'), TRUE))
			{
				$$item = $this->convert_ascii($$item);
			}
		}

		// Build the Trackback data string
		$charset = isset($tb_data['charset']) ? $tb_data['charset'] : $this->charset;

		$data = 'url='.rawurlencode($url).'&title='.rawurlencode($title).'&blog_name='.rawurlencode($blog_name)
			.'&excerpt='.rawurlencode($excerpt).'&charset='.rawurlencode($charset);

		// Send Trackback(s)
		$return = TRUE;
		if (count($ping_url) > 0)
		{
			foreach ($ping_url as $url)
			{
				if ($this->process($url, $data) === FALSE)
				{
					$return = FALSE;
				}
			}
		}

		return $return;
	}

	// --------------------------------------------------------------------

	/**
	 * Receive Trackback  Data
	 *
	 * This function simply validates the incoming TB data.
	 * It returns FALSE on failure and TRUE on success.
	 * If the data is valid it is set to the $this->data array
	 * so that it can be inserted into a database.
	 *
	 * @return	bool
	 */
	public function receive()
	{
		foreach (array('url', 'title', 'blog_name', 'excerpt') as $val)
		{
			if (empty($_POST[$val]))
			{
				$this->set_error('The following required POST variable is missing: '.$val);
				return FALSE;
			}

			$this->data['charset'] = isset($_POST['charset']) ? strtoupper(trim($_POST['charset'])) : 'auto';

			if ($val !== 'url' && MB_ENABLED === TRUE)
			{
				if (MB_ENABLED === TRUE)
				{
					$_POST[$val] = mb_convert_encoding($_POST[$val], $this->charset, $this->data['charset']);
				}
				elseif (ICONV_ENABLED === TRUE)
				{
					$_POST[$val] = @iconv($this->data['charset'], $this->charset.'//IGNORE', $_POST[$val]);
				}
			}

			$_POST[$val] = ($val !== 'url') ? $this->convert_xml(strip_tags($_POST[$val])) : strip_tags($_POST[$val]);

			if ($val === 'excerpt')
			{
				$_POST['excerpt'] = $this->limit_characters($_POST['excerpt']);
			}

			$this->data[$val] = $_POST[$val];
		}

		return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	 * Send Trackback Error Message
	 *
	 * Allows custom errors to be set. By default it
	 * sends the "incomplete information" error, as that's
	 * the most common one.
	 *
	 * @param	string
	 * @return	void
	 */
	public function send_error($message = 'Incomplete Information')
	{
		exit('<?xml version="1.0" encoding="utf-8"?'.">\n<response>\n<error>1</error>\n<message>".$message."</message>\n</response>");
	}

	// --------------------------------------------------------------------

	/**
	 * Send Trackback Success Message
	 *
	 * This should be called when a trackback has been
	 * successfully received and inserted.
	 *
	 * @return	void
	 */
	public function send_success()
	{
		exit('<?xml version="1.0" encoding="utf-8"?'.">\n<response>\n<error>0</error>\n</response>");
	}

	// --------------------------------------------------------------------

	/**
	 * Fetch a particular item
	 *
	 * @param	string
	 * @return	string
	 */
	public function data($item)
	{
		return isset($this->data[$item]) ? $this->data[$item] : '';
	}

	// --------------------------------------------------------------------

	/**
	 * Process Trackback
	 *
	 * Opens a socket connection and passes the data to
	 * the server. Returns TRUE on success, FALSE on failure
	 *
	 * @param	string
	 * @param	string
	 * @return	bool
	 */
	public function process($url, $data)
	{
		$target = parse_url($url);

		// Open the socket
		if ( ! $fp = @fsockopen($target['host'], 80))
		{
			$this->set_error('Invalid Connection: '.$url);
			return FALSE;
		}

		// Build the path
		$path = isset($target['path']) ? $target['path'] : $url;
		empty($target['query']) OR $path .= '?'.$target['query'];

		// Add the Trackback ID to the data string
		if ($id = $this->get_id($url))
		{
			$data = 'tb_id='.$id.'&'.$data;
		}

		// Transfer the data
		fputs($fp, 'POST '.$path." HTTP/1.0\r\n");
		fputs($fp, 'Host: '.$target['host']."\r\n");
		fputs($fp, "Content-type: application/x-www-form-urlencoded\r\n");
		fputs($fp, 'Content-length: '.strlen($data)."\r\n");
		fputs($fp, "Connection: close\r\n\r\n");
		fputs($fp, $data);

		// Was it successful?

		$this->response = '';
		while ( ! feof($fp))
		{
			$this->response .= fgets($fp, 128);
		}
		@fclose($fp);

		if (stripos($this->response, '<error>0</error>') === FALSE)
		{
			$message = preg_match('/<message>(.*?)<\/message>/is', $this->response, $match)
				? trim($match[1])
				: 'An unknown error was encountered';
			$this->set_error($message);
			return FALSE;
		}

		return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	 * Extract Trackback URLs
	 *
	 * This function lets multiple trackbacks be sent.
	 * It takes a string of URLs (separated by comma or
	 * space) and puts each URL into an array
	 *
	 * @param	string
	 * @return	string
	 */
	public function extract_urls($urls)
	{
		// Remove the pesky white space and replace with a comma, then replace doubles.
		$urls = str_replace(',,', ',', preg_replace('/\s*(\S+)\s*/', '\\1,', $urls));

		// Break into an array via commas and remove duplicates
		$urls = array_unique(preg_split('/[,]/', rtrim($urls, ',')));

		array_walk($urls, array($this, 'validate_url'));
		return $urls;
	}

	// --------------------------------------------------------------------

	/**
	 * Validate URL
	 *
	 * Simply adds "http://" if missing
	 *
	 * @param	string
	 * @return	void
	 */
	public function validate_url(&$url)
	{
		$url = trim($url);

		if (strpos($url, 'http') !== 0)
		{
			$url = 'http://'.$url;
		}
	}

	// --------------------------------------------------------------------

	/**
	 * Find the Trackback URL's ID
	 *
	 * @param	string
	 * @return	string
	 */
	public function get_id($url)
	{
		$tb_id = '';

		if (strpos($url, '?') !== FALSE)
		{
			$tb_array = explode('/', $url);
			$tb_end   = $tb_array[count($tb_array)-1];

			if ( ! is_numeric($tb_end))
			{
				$tb_end  = $tb_array[count($tb_array)-2];
			}

			$tb_array = explode('=', $tb_end);
			$tb_id	= $tb_array[count($tb_array)-1];
		}
		else
		{
			$url = rtrim($url, '/');

			$tb_array = explode('/', $url);
			$tb_id	= $tb_array[count($tb_array)-1];

			if ( ! is_numeric($tb_id))
			{
				$tb_id = $tb_array[count($tb_array)-2];
			}
		}

		return ctype_digit((string) $tb_id) ? $tb_id : FALSE;
	}

	// --------------------------------------------------------------------

	/**
	 * Convert Reserved XML characters to Entities
	 *
	 * @param	string
	 * @return	string
	 */
	public function convert_xml($str)
	{
		$temp = '__TEMP_AMPERSANDS__';

		$str = preg_replace(array('/&#(\d+);/', '/&(\w+);/'), $temp.'\\1;', $str);

		$str = str_replace(array('&', '<', '>', '"', "'", '-'),
					array('&amp;', '&lt;', '&gt;', '&quot;', '&#39;', '&#45;'),
					$str);

		return preg_replace(array('/'.$temp.'(\d+);/', '/'.$temp.'(\w+);/'), array('&#\\1;', '&\\1;'), $str);
	}

	// --------------------------------------------------------------------

	/**
	 * Character limiter
	 *
	 * Limits the string based on the character count. Will preserve complete words.
	 *
	 * @param	string
	 * @param	int
	 * @param	string
	 * @return	string
	 */
	public function limit_characters($str, $n = 500, $end_char = '&#8230;')
	{
		if (strlen($str) < $n)
		{
			return $str;
		}

		$str = preg_replace('/\s+/', ' ', str_replace(array("\r\n", "\r", "\n"), ' ', $str));

		if (strlen($str) <= $n)
		{
			return $str;
		}

		$out = '';
		foreach (explode(' ', trim($str)) as $val)
		{
			$out .= $val.' ';
			if (strlen($out) >= $n)
			{
				return rtrim($out).$end_char;
			}
		}
	}

	// --------------------------------------------------------------------

	/**
	 * High ASCII to Entities
	 *
	 * Converts Hight ascii text and MS Word special chars
	 * to character entities
	 *
	 * @param	string
	 * @return	string
	 */
	public function convert_ascii($str)
	{
		$count	= 1;
		$out	= '';
		$temp	= array();

		for ($i = 0, $s = strlen($str); $i < $s; $i++)
		{
			$ordinal = ord($str[$i]);

			if ($ordinal < 128)
			{
				$out .= $str[$i];
			}
			else
			{
				if (count($temp) === 0)
				{
					$count = ($ordinal < 224) ? 2 : 3;
				}

				$temp[] = $ordinal;

				if (count($temp) === $count)
				{
					$number = ($count === 3)
						? (($temp[0] % 16) * 4096) + (($temp[1] % 64) * 64) + ($temp[2] % 64)
						: (($temp[0] % 32) * 64) + ($temp[1] % 64);

					$out .= '&#'.$number.';';
					$count = 1;
					$temp = array();
				}
			}
		}

		return $out;
	}

	// --------------------------------------------------------------------

	/**
	 * Set error message
	 *
	 * @param	string
	 * @return	void
	 */
	public function set_error($msg)
	{
		log_message('error', $msg);
		$this->error_msg[] = $msg;
	}

	// --------------------------------------------------------------------

	/**
	 * Show error messages
	 *
	 * @param	string
	 * @param	string
	 * @return	string
	 */
	public function display_errors($open = '<p>', $close = '</p>')
	{
		return (count($this->error_msg) > 0) ? $open.implode($close.$open, $this->error_msg).$close : '';
	}

}