<?php
/**
* Class to improve the seo of the site
*
* @package OC
* @category SEO
* @author Chema <chema@open-classifieds.com>
* @version 1.0
* @date 21-02-2014
* @url http://garridodiaz.com/phpseo/
* @copyright (c) 2009-2014 Open Classifieds Team
* @license GPL v3
*
* @notes
* length of title and description from:
* http://moz.com/learn/seo/meta-description
* http://moz.com/learn/seo/title-tag
* remember keywords are useless!! http://googlewebmastercentral.blogspot.com/2009/09/google-does-not-use-keywords-meta-tag.html
*
* @usage
* seo::$charset = Kohana::$charset;
* $this->template->title = seo::text($this->template->title, 70);
* $this->template->meta_keywords = seo::keywords($this->template->meta_description);
* $this->template->meta_description = seo::text($this->template->meta_description);
*/
class seo{
/**
* default charset to use
* @var string
*/
public static $charset = 'UTF-8';
/**
* banned words in english feel free to change them
* @var array
*/
public static $banned_words = array();
//public static $banned_words = array('able', 'about', 'above', 'act', 'add', 'afraid', 'after', 'again', 'against', 'age', 'ago', 'agree', 'all', 'almost', 'alone', 'along', 'already', 'also', 'although', 'always', 'am', 'amount', 'an', 'and', 'anger', 'angry', 'animal', 'another', 'answer', 'any', 'appear', 'apple', 'are', 'arrive', 'arm', 'arms', 'around', 'arrive', 'as', 'ask', 'at', 'attempt', 'aunt', 'away', 'back', 'bad', 'bag', 'bay', 'be', 'became', 'because', 'become', 'been', 'before', 'began', 'begin', 'behind', 'being', 'bell', 'belong', 'below', 'beside', 'best', 'better', 'between', 'beyond', 'big', 'body', 'bone', 'born', 'borrow', 'both', 'bottom', 'box', 'boy', 'break', 'bring', 'brought', 'bug', 'built', 'busy', 'but', 'buy', 'by', 'call', 'came', 'can', 'cause', 'choose', 'close', 'close', 'consider', 'come', 'consider', 'considerable', 'contain', 'continue', 'could', 'cry', 'cut', 'dare', 'dark', 'deal', 'dear', 'decide', 'deep', 'did', 'die', 'do', 'does', 'dog', 'done', 'doubt', 'down', 'during', 'each', 'ear', 'early', 'eat', 'effort', 'either', 'else', 'end', 'enjoy', 'enough', 'enter', 'even', 'ever', 'every', 'except', 'expect', 'explain', 'fail', 'fall', 'far', 'fat', 'favor', 'fear', 'feel', 'feet', 'fell', 'felt', 'few', 'fill', 'find', 'fit', 'fly', 'follow', 'for', 'forever', 'forget', 'from', 'front', 'gave', 'get', 'gives', 'goes', 'gone', 'good', 'got', 'gray', 'great', 'green', 'grew', 'grow', 'guess', 'had', 'half', 'hang', 'happen', 'has', 'hat', 'have', 'he', 'hear', 'heard', 'held', 'hello', 'help', 'her', 'here', 'hers', 'high', 'hill', 'him', 'his', 'hit', 'hold', 'hot', 'how', 'however', 'I', 'if', 'ill', 'in', 'indeed', 'instead', 'into', 'iron', 'is', 'it', 'its', 'just', 'keep', 'kept', 'knew', 'know', 'known', 'late', 'least', 'led', 'left', 'lend', 'less', 'let', 'like', 'likely', 'likr', 'lone', 'long', 'look', 'lot', 'make', 'many', 'may', 'me', 'mean', 'met', 'might', 'mile', 'mine', 'moon', 'more', 'most', 'move', 'much', 'must', 'my', 'near', 'nearly', 'necessary', 'neither', 'never', 'next', 'no', 'none', 'nor', 'not', 'note', 'nothing', 'now', 'number', 'of', 'off', 'often', 'oh', 'on', 'once', 'only', 'or', 'other', 'ought', 'our', 'out', 'please', 'prepare', 'probable', 'pull', 'pure', 'push', 'put', 'raise', 'ran', 'rather', 'reach', 'realize', 'reply', 'require', 'rest', 'run', 'said', 'same', 'sat', 'saw', 'say', 'see', 'seem', 'seen', 'self', 'sell', 'sent', 'separate', 'set', 'shall', 'she', 'should', 'side', 'sign', 'since', 'so', 'sold', 'some', 'soon', 'sorry', 'stay', 'step', 'stick', 'still', 'stood', 'such', 'sudden', 'suppose', 'take', 'taken', 'talk', 'tall', 'tell', 'ten', 'than', 'thank', 'that', 'the', 'their', 'them', 'then', 'there', 'therefore', 'these', 'they', 'this', 'those', 'though', 'through', 'till', 'to', 'today', 'told', 'tomorrow', 'too', 'took', 'tore', 'tought', 'toward', 'tried', 'tries', 'trust', 'try', 'turn', 'two', 'under', 'until', 'up', 'upon', 'us', 'use', 'usual', 'various', 'verb', 'very', 'visit', 'want', 'was', 'we', 'well', 'went', 'were', 'what', 'when', 'where', 'whether', 'which', 'while', 'white', 'who', 'whom', 'whose', 'why', 'will', 'with', 'within', 'without', 'would', 'yes', 'yet', 'you', 'young', 'your', 'br', 'img', 'p','lt', 'gt', 'quot', 'copy');
/**
* min len for a word in the keywords
* @var integer
*/
public static $min_word_length = 4;
/**
* SEO for text length
* returns a text with text
* @param integer $length of the description
* @return string
*/
public static function text($text, $length = 160)
{
return self::limit_chars(self::clean($text), $length,'',TRUE);
}
/**
* gets the keyword from the text in the construct
*
* @param integer $max_keys number of keywords
* @return string
*/
public static function keywords($text, $max_keys = 25)
{
//array to keep word->number of repetitions
$wordcount = array_count_values(str_word_count(self::clean($text),1));
//remove small words
foreach ($wordcount as $key => $value)
{
if ( (strlen($key)<= self::$min_word_length) OR in_array($key, self::$banned_words))
unset($wordcount[$key]);
}
//sort keywords from most repetitions to less
uasort($wordcount,array('self','cmp'));
//keep only X keywords
$wordcount = array_slice($wordcount,0, $max_keys);
//return keywords on a string
return implode(', ', array_keys($wordcount));
}
/**
* cleans an string from HTML spaces etc...
* @param string $text
* @return string
*/
private static function clean($text)
{
$text = html_entity_decode($text,ENT_QUOTES,self::$charset);
$text = strip_tags($text);//erases any html markup
$text = preg_replace('/\s\s+/', ' ', $text);//erase possible duplicated white spaces
$text = str_replace (array('\r\n', '\n', '+'), ',', $text);//replace possible returns
return trim($text);
}
/**
* sort for uasort descendent numbers , compares values
* @param integer $a
* @param integer $b
* @return integer
*/
private static function cmp($a, $b)
{
if ($a == $b) return 0;
return ($a < $b) ? 1 : -1;
}
/**
* Limits a phrase to a given number of characters.
* ported from kohana text class, so this class can remain as independent as possible
* $text = Text::limit_chars($text);
*
* @param string $str phrase to limit characters of
* @param integer $limit number of characters to limit to
* @param string $end_char end character or entity
* @param boolean $preserve_words enable or disable the preservation of words while limiting
* @return string
*/
private static function limit_chars($str, $limit = 100, $end_char = NULL, $preserve_words = FALSE)
{
$end_char = ($end_char === NULL) ? '…' : $end_char;
$limit = (int) $limit;
if (trim($str) === '' OR mb_strlen($str) <= $limit)
return $str;
if ($limit <= 0)
return $end_char;
if ($preserve_words === FALSE)
return rtrim(mb_substr($str, 0, $limit)).$end_char;
// Don't preserve words. The limit is considered the top limit.
// No strings with a length longer than $limit should be returned.
if ( ! preg_match('/^.{0,'.$limit.'}\s/us', $str, $matches))
return $end_char;
return rtrim($matches[0]).((strlen($matches[0]) === strlen($str)) ? '' : $end_char);
}
}
//end seo class
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