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<?php
/**
* Zend Framework
*
* LICENSE
*
* This source file is subject to the new BSD license that is bundled
* with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://framework.zend.com/license/new-bsd
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@zend.com so we can send you a copy immediately.
*
* @category Zend
* @package Zend_Search_Lucene
* @subpackage Search
* @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @version $Id: Fuzzy.php 18954 2009-11-12 20:01:33Z alexander $
*/
/** Zend_Search_Lucene_Search_Query_Processing */
require_once 'Zend/Search/Lucene/Search/Query/Preprocessing.php';
/**
* It's an internal abstract class intended to finalize ase a query processing after query parsing.
* This type of query is not actually involved into query execution.
*
* @category Zend
* @package Zend_Search_Lucene
* @subpackage Search
* @internal
* @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
class Zend_Search_Lucene_Search_Query_Preprocessing_Fuzzy extends Zend_Search_Lucene_Search_Query_Preprocessing
{
/**
* word (query parser lexeme) to find.
*
* @var string
*/
private $_word;
/**
* Word encoding (field name is always provided using UTF-8 encoding since it may be retrieved from index).
*
* @var string
*/
private $_encoding;
/**
* Field name.
*
* @var string
*/
private $_field;
/**
* A value between 0 and 1 to set the required similarity
* between the query term and the matching terms. For example, for a
* _minimumSimilarity of 0.5 a term of the same length
* as the query term is considered similar to the query term if the edit distance
* between both terms is less than length(term)*0.5
*
* @var float
*/
private $_minimumSimilarity;
/**
* Class constructor. Create a new preprocessing object for prase query.
*
* @param string $word Non-tokenized word (query parser lexeme) to search.
* @param string $encoding Word encoding.
* @param string $fieldName Field name.
* @param float $minimumSimilarity minimum similarity
*/
public function __construct($word, $encoding, $fieldName, $minimumSimilarity)
{
$this->_word = $word;
$this->_encoding = $encoding;
$this->_field = $fieldName;
$this->_minimumSimilarity = $minimumSimilarity;
}
/**
* Re-write query into primitive queries in the context of specified index
*
* @param Zend_Search_Lucene_Interface $index
* @return Zend_Search_Lucene_Search_Query
*/
public function rewrite(Zend_Search_Lucene_Interface $index)
{
if ($this->_field === null) {
require_once 'Zend/Search/Lucene/Search/Query/Boolean.php';
$query = new Zend_Search_Lucene_Search_Query_Boolean();
$hasInsignificantSubqueries = false;
require_once 'Zend/Search/Lucene.php';
if (Zend_Search_Lucene::getDefaultSearchField() === null) {
$searchFields = $index->getFieldNames(true);
} else {
$searchFields = array(Zend_Search_Lucene::getDefaultSearchField());
}
require_once 'Zend/Search/Lucene/Search/Query/Preprocessing/Fuzzy.php';
foreach ($searchFields as $fieldName) {
$subquery = new Zend_Search_Lucene_Search_Query_Preprocessing_Fuzzy($this->_word,
$this->_encoding,
$fieldName,
$this->_minimumSimilarity);
$rewrittenSubquery = $subquery->rewrite($index);
if ( !($rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Insignificant ||
$rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Empty) ) {
$query->addSubquery($rewrittenSubquery);
}
if ($rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Insignificant) {
$hasInsignificantSubqueries = true;
}
}
$subqueries = $query->getSubqueries();
if (count($subqueries) == 0) {
$this->_matches = array();
if ($hasInsignificantSubqueries) {
require_once 'Zend/Search/Lucene/Search/Query/Insignificant.php';
return new Zend_Search_Lucene_Search_Query_Insignificant();
} else {
require_once 'Zend/Search/Lucene/Search/Query/Empty.php';
return new Zend_Search_Lucene_Search_Query_Empty();
}
}
if (count($subqueries) == 1) {
$query = reset($subqueries);
}
$query->setBoost($this->getBoost());
$this->_matches = $query->getQueryTerms();
return $query;
}
// -------------------------------------
// Recognize exact term matching (it corresponds to Keyword fields stored in the index)
// encoding is not used since we expect binary matching
require_once 'Zend/Search/Lucene/Index/Term.php';
$term = new Zend_Search_Lucene_Index_Term($this->_word, $this->_field);
if ($index->hasTerm($term)) {
require_once 'Zend/Search/Lucene/Search/Query/Fuzzy.php';
$query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);
$query->setBoost($this->getBoost());
// Get rewritten query. Important! It also fills terms matching container.
$rewrittenQuery = $query->rewrite($index);
$this->_matches = $query->getQueryTerms();
return $rewrittenQuery;
}
// -------------------------------------
// Recognize wildcard queries
/** @todo check for PCRE unicode support may be performed through Zend_Environment in some future */
if (@preg_match('/\pL/u', 'a') == 1) {
$subPatterns = preg_split('/[*?]/u', iconv($this->_encoding, 'UTF-8', $this->_word));
} else {
$subPatterns = preg_split('/[*?]/', $this->_word);
}
if (count($subPatterns) > 1) {
require_once 'Zend/Search/Lucene/Search/QueryParserException.php';
throw new Zend_Search_Lucene_Search_QueryParserException('Fuzzy search doesn\'t support wildcards (except within Keyword fields).');
}
// -------------------------------------
// Recognize one-term multi-term and "insignificant" queries
require_once 'Zend/Search/Lucene/Analysis/Analyzer.php';
$tokens = Zend_Search_Lucene_Analysis_Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);
if (count($tokens) == 0) {
$this->_matches = array();
require_once 'Zend/Search/Lucene/Search/Query/Insignificant.php';
return new Zend_Search_Lucene_Search_Query_Insignificant();
}
if (count($tokens) == 1) {
require_once 'Zend/Search/Lucene/Index/Term.php';
$term = new Zend_Search_Lucene_Index_Term($tokens[0]->getTermText(), $this->_field);
require_once 'Zend/Search/Lucene/Search/Query/Fuzzy.php';
$query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);
$query->setBoost($this->getBoost());
// Get rewritten query. Important! It also fills terms matching container.
$rewrittenQuery = $query->rewrite($index);
$this->_matches = $query->getQueryTerms();
return $rewrittenQuery;
}
// Word is tokenized into several tokens
require_once 'Zend/Search/Lucene/Search/QueryParserException.php';
throw new Zend_Search_Lucene_Search_QueryParserException('Fuzzy search is supported only for non-multiple word terms');
}
/**
* Query specific matches highlighting
*
* @param Zend_Search_Lucene_Search_Highlighter_Interface $highlighter Highlighter object (also contains doc for highlighting)
*/
protected function _highlightMatches(Zend_Search_Lucene_Search_Highlighter_Interface $highlighter)
{
/** Skip fields detection. We don't need it, since we expect all fields presented in the HTML body and don't differentiate them */
/** Skip exact term matching recognition, keyword fields highlighting is not supported */
// -------------------------------------
// Recognize wildcard queries
/** @todo check for PCRE unicode support may be performed through Zend_Environment in some future */
if (@preg_match('/\pL/u', 'a') == 1) {
$subPatterns = preg_split('/[*?]/u', iconv($this->_encoding, 'UTF-8', $this->_word));
} else {
$subPatterns = preg_split('/[*?]/', $this->_word);
}
if (count($subPatterns) > 1) {
// Do nothing
return;
}
// -------------------------------------
// Recognize one-term multi-term and "insignificant" queries
require_once 'Zend/Search/Lucene/Analysis/Analyzer.php';
$tokens = Zend_Search_Lucene_Analysis_Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);
if (count($tokens) == 0) {
// Do nothing
return;
}
if (count($tokens) == 1) {
require_once 'Zend/Search/Lucene/Index/Term.php';
$term = new Zend_Search_Lucene_Index_Term($tokens[0]->getTermText(), $this->_field);
require_once 'Zend/Search/Lucene/Search/Query/Fuzzy.php';
$query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);
$query->_highlightMatches($highlighter);
return;
}
// Word is tokenized into several tokens
// But fuzzy search is supported only for non-multiple word terms
// Do nothing
}
/**
* Print a query
*
* @return string
*/
public function __toString()
{
// It's used only for query visualisation, so we don't care about characters escaping
if ($this->_field !== null) {
$query = $this->_field . ':';
} else {
$query = '';
}
$query .= $this->_word;
if ($this->getBoost() != 1) {
$query .= '^' . round($this->getBoost(), 4);
}
return $query;
}
}
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