<?php
/**
* @author Mike Cochrane <mikec@mikenz.geek.nz>
* @author Nick Pope <nick@nickpope.me.uk>
* @copyright Copyright © 2010, Mike Cochrane, Nick Pope
* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License v2.0
* @package Twitter
*/
require_once 'Regex.php';
/**
* Twitter Autolink Class
*
* Parses tweets and generates HTML anchor tags around URLs, usernames,
* username/list pairs and hashtags.
*
* Originally written by {@link http://github.com/mikenz Mike Cochrane}, this
* is based on code by {@link http://github.com/mzsanford Matt Sanford} and
* heavily modified by {@link http://github.com/ngnpope Nick Pope}.
*
* @author Mike Cochrane <mikec@mikenz.geek.nz>
* @author Nick Pope <nick@nickpope.me.uk>
* @copyright Copyright © 2010, Mike Cochrane, Nick Pope
* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License v2.0
* @package Twitter
*/
class Twitter_Autolink extends Twitter_Regex {
/**
* CSS class for auto-linked URLs.
*
* @var string
*/
protected $class_url = 'url';
/**
* CSS class for auto-linked username URLs.
*
* @var string
*/
protected $class_user = 'username';
/**
* CSS class for auto-linked list URLs.
*
* @var string
*/
protected $class_list = 'list';
/**
* CSS class for auto-linked hashtag URLs.
*
* @var string
*/
protected $class_hash = 'hashtag';
/**
* URL base for username links (the username without the @ will be appended).
*
* @var string
*/
protected $url_base_user = BASE_URL;
/**
* URL base for list links (the username/list without the @ will be appended).
*
* @var string
*/
protected $url_base_list = BASE_URL;
/**
* URL base for hashtag links (the hashtag without the # will be appended).
*
* @var string
*/
protected $url_base_hash = BASE_URL;
/**
* Whether to include the value 'nofollow' in the 'rel' attribute.
*
* @var bool
*/
protected $nofollow = true;
/**
* Whether to include the value 'external' in the 'rel' attribute.
*
* Often this is used to be matched on in JavaScript for dynamically adding
* the 'target' attribute which is deprecated in HTML 4.01. In HTML 5 it has
* been undeprecated and thus the 'target' attribute can be used. If this is
* set to false then the 'target' attribute will be output.
*
* @var bool
*/
protected $external = true;
/**
* The scope to open the link in.
*
* Support for the 'target' attribute was deprecated in HTML 4.01 but has
* since been reinstated in HTML 5. To output the 'target' attribute you
* must disable the adding of the string 'external' to the 'rel' attribute.
*
* @var string
*/
protected $target = '_blank';
/**
* Provides fluent method chaining.
*
* @param string $tweet The tweet to be converted.
* @param bool $full_encode Whether to encode all special characters.
*
* @see __construct()
*
* @return Twitter_Autolink
*/
public static function create($tweet, $full_encode = false) {
return new self($tweet, $full_encode);
}
/**
* Reads in a tweet to be parsed and converted to contain links.
*
* As the intent is to produce links and output the modified tweet to the
* user, we take this opportunity to ensure that we escape user input.
*
* @see htmlspecialchars()
*
* @param string $tweet The tweet to be converted.
* @param bool $escape Whether to escape the tweet (default: true).
* @param bool $full_encode Whether to encode all special characters.
*/
public function __construct($tweet, $escape = true, $full_encode = false) {
if ($escape) {
if ($full_encode) {
parent::__construct(htmlentities($tweet, ENT_QUOTES, 'UTF-8', false));
} else {
parent::__construct(htmlspecialchars($tweet, ENT_QUOTES, 'UTF-8', false));
}
} else {
parent::__construct($tweet);
}
}
/**
* CSS class for auto-linked URLs.
*
* @return string CSS class for URL links.
*/
public function getURLClass() {
return $this->class_url;
}
/**
* CSS class for auto-linked URLs.
*
* @param string $v CSS class for URL links.
*
* @return Twitter_Autolink Fluid method chaining.
*/
public function setURLClass($v) {
$this->class_url = trim($v);
return $this;
}
/**
* CSS class for auto-linked username URLs.
*
* @return string CSS class for username links.
*/
public function getUsernameClass() {
return $this->class_user;
}
/**
* CSS class for auto-linked username URLs.
*
* @param string $v CSS class for username links.
*
* @return Twitter_Autolink Fluid method chaining.
*/
public function setUsernameClass($v) {
$this->class_user = trim($v);
return $this;
}
/**
* CSS class for auto-linked username/list URLs.
*
* @return string CSS class for username/list links.
*/
public function getListClass() {
return $this->class_list;
}
/**
* CSS class for auto-linked username/list URLs.
*
* @param string $v CSS class for username/list links.
*
* @return Twitter_Autolink Fluid method chaining.
*/
public function setListClass($v) {
$this->class_list = trim($v);
return $this;
}
/**
* CSS class for auto-linked hashtag URLs.
*
* @return string CSS class for hashtag links.
*/
public function getHashtagClass() {
return $this->class_hash;
}
/**
* CSS class for auto-linked hashtag URLs.
*
* @param string $v CSS class for hashtag links.
*
* @return Twitter_Autolink Fluid method chaining.
*/
public function setHashtagClass($v) {
$this->class_hash = trim($v);
return $this;
}
/**
* Whether to include the value 'nofollow' in the 'rel' attribute.
*
* @return bool Whether to add 'nofollow' to the 'rel' attribute.
*/
public function getNoFollow() {
return $this->nofollow;
}
/**
* Whether to include the value 'nofollow' in the 'rel' attribute.
*
* @param bool $v The value to add to the 'target' attribute.
*
* @return Twitter_Autolink Fluid method chaining.
*/
public function setNoFollow($v) {
$this->nofollow = $v;
return $this;
}
/**
* Whether to include the value 'external' in the 'rel' attribute.
*
* Often this is used to be matched on in JavaScript for dynamically adding
* the 'target' attribute which is deprecated in HTML 4.01. In HTML 5 it has
* been undeprecated and thus the 'target' attribute can be used. If this is
* set to false then the 'target' attribute will be output.
*
* @return bool Whether to add 'external' to the 'rel' attribute.
*/
public function getExternal() {
return $this->external;
}
/**
* Whether to include the value 'external' in the 'rel' attribute.
*
* Often this is used to be matched on in JavaScript for dynamically adding
* the 'target' attribute which is deprecated in HTML 4.01. In HTML 5 it has
* been undeprecated and thus the 'target' attribute can be used. If this is
* set to false then the 'target' attribute will be output.
*
* @param bool $v The value to add to the 'target' attribute.
*
* @return Twitter_Autolink Fluid method chaining.
*/
public function setExternal($v) {
$this->external = $v;
return $this;
}
/**
* The scope to open the link in.
*
* Support for the 'target' attribute was deprecated in HTML 4.01 but has
* since been reinstated in HTML 5. To output the 'target' attribute you
* must disable the adding of the string 'external' to the 'rel' attribute.
*
* @return string The value to add to the 'target' attribute.
*/
public function getTarget() {
return $this->target;
}
/**
* The scope to open the link in.
*
* Support for the 'target' attribute was deprecated in HTML 4.01 but has
* since been reinstated in HTML 5. To output the 'target' attribute you
* must disable the adding of the string 'external' to the 'rel' attribute.
*
* @param string $v The value to add to the 'target' attribute.
*
* @return Twitter_Autolink Fluid method chaining.
*/
public function setTarget($v) {
$this->target = trim($v);
return $this;
}
/**
* Adds links to all elements in the tweet.
*
* @return string The modified tweet.
*/
public function addLinks() {
$original = $this->tweet;
$this->tweet = $this->addLinksToURLs();
$this->tweet = $this->addLinksToHashtags();
$this->tweet = $this->addLinksToUsernamesAndLists();
$modified = $this->tweet;
$this->tweet = $original;
return $modified;
}
/**
* Adds links to hashtag elements in the tweet.
*
* @return string The modified tweet.
*/
public function addLinksToHashtags() {
return preg_replace_callback(
self::REGEX_HASHTAG,
array($this, '_addLinksToHashtags'),
$this->tweet);
}
/**
* Adds links to URL elements in the tweet.
*
* @return string The modified tweet.
*/
public function addLinksToURLs() {
return preg_replace_callback(
self::$REGEX_VALID_URL,
array($this, '_addLinksToURLs'),
$this->tweet);
}
/**
* Adds links to username/list elements in the tweet.
*
* @return string The modified tweet.
*/
public function addLinksToUsernamesAndLists() {
return preg_replace_callback(
self::REGEX_USERNAME_LIST,
array($this, '_addLinksToUsernamesAndLists'),
$this->tweet);
}
/**
* Wraps a tweet element in an HTML anchor tag using the provided URL.
*
* This is a helper function to perform the generation of the link.
*
* @param string $url The URL to use as the href.
* @param string $class The CSS class(es) to apply (space separated).
* @param string $element The tweet element to wrap.
*
* @return string The tweet element with a link applied.
*/
protected function wrap($url, $class, $element) {
$link = '<a';
if ($class) $link .= ' class="'.$class.'"';
$link .= ' href="'.$url.'"';
$rel = array();
if ($this->external) $rel[] = 'external';
if ($this->nofollow) $rel[] = 'nofollow';
if (!empty($rel)) $link .= ' rel="'.implode(' ', $rel).'"';
if ($this->target) $link .= ' target="'.$this->target.'"';
$link .= '>'.$element.'</a>';
return $link;
}
/**
* Callback used by the method that adds links to hashtags.
*
* @see addLinksToHashtags()
*
* @param array $matches The regular expression matches.
*
* @return string The link-wrapped hashtag.
*/
protected function _addLinksToHashtags($matches) {
$replacement = $matches[1];
$element = $matches[2] . $matches[3];
$url = $this->url_base_hash . 'hash/' . $matches[3];
$replacement .= $this->wrap($url, $this->class_hash, $element);
return $replacement;
}
/**
* Callback used by the method that adds links to URLs.
*
* @see addLinksToURLs()
*
* @param array $matches The regular expression matches.
*
* @return string The link-wrapped URL.
*/
protected function _addLinksToURLs($matches) {
list($all, $before, $url, $protocol, $domain, $path, $query) = array_pad($matches, 7, '');
$url = htmlspecialchars($url, ENT_QUOTES, 'UTF-8', false);
if (!$protocol && !preg_match(self::REGEX_PROBABLE_TLD, $domain)) return $all;
$href = ((!$protocol || strtolower($protocol) === 'www.') ? 'http://'.$url : $url);
return $before . $this->wrap($href, $this->class_url, $url);
}
/**
* Callback used by the method that adds links to username/list pairs.
*
* @see addLinksToUsernamesAndLists()
*
* @param array $matches The regular expression matches.
*
* @return string The link-wrapped username/list pair.
*/
protected function _addLinksToUsernamesAndLists($matches) {
list($all, $before, $at, $username, $slash_listname, $after) = array_pad($matches, 6, '');
# If $after is not empty, there is an invalid character.
if (!empty($after)) return $all;
if (!empty($slash_listname)) {
# Replace the list and username
$element = $username . substr($slash_listname, 0, 26);
$class = $this->class_list;
$url = $this->url_base_list . 'lists/' . $element;
$postfix = substr($slash_listname, 26);
} else {
# Replace the username
$element = $username;
$class = $this->class_user;
$url = $this->url_base_user . 'user/' . $element;
$postfix = '';
}
return $before . $at . $this->wrap($url, $class, $element) . $postfix . $after;
}
}