wiki.techinc.nl/includes/SearchEngine.php

704 lines
15 KiB
PHP

<?php
/**
* Contain a class for special pages
* @addtogroup Search
*/
class SearchEngine {
var $limit = 10;
var $offset = 0;
var $searchTerms = array();
var $namespaces = array( NS_MAIN );
var $showRedirects = false;
/**
* Perform a full text search query and return a result set.
* If title searches are not supported or disabled, return null.
*
* @param string $term - Raw search term
* @return SearchResultSet
* @access public
* @abstract
*/
function searchText( $term ) {
return null;
}
/**
* Perform a title-only search query and return a result set.
* If title searches are not supported or disabled, return null.
*
* @param string $term - Raw search term
* @return SearchResultSet
* @access public
* @abstract
*/
function searchTitle( $term ) {
return null;
}
/**
* If an exact title match can be find, or a very slightly close match,
* return the title. If no match, returns NULL.
*
* @param string $term
* @return Title
*/
public static function getNearMatch( $searchterm ) {
global $wgContLang;
$allSearchTerms = array($searchterm);
if($wgContLang->hasVariants()){
$allSearchTerms = array_merge($allSearchTerms,$wgContLang->convertLinkToAllVariants($searchterm));
}
foreach($allSearchTerms as $term){
# Exact match? No need to look further.
$title = Title::newFromText( $term );
if (is_null($title))
return NULL;
if ( $title->getNamespace() == NS_SPECIAL || $title->exists() ) {
return $title;
}
# Now try all lower case (i.e. first letter capitalized)
#
$title = Title::newFromText( $wgContLang->lc( $term ) );
if ( $title->exists() ) {
return $title;
}
# Now try capitalized string
#
$title = Title::newFromText( $wgContLang->ucwords( $term ) );
if ( $title->exists() ) {
return $title;
}
# Now try all upper case
#
$title = Title::newFromText( $wgContLang->uc( $term ) );
if ( $title->exists() ) {
return $title;
}
# Now try Word-Caps-Breaking-At-Word-Breaks, for hyphenated names etc
$title = Title::newFromText( $wgContLang->ucwordbreaks($term) );
if ( $title->exists() ) {
return $title;
}
global $wgCapitalLinks, $wgContLang;
if( !$wgCapitalLinks ) {
// Catch differs-by-first-letter-case-only
$title = Title::newFromText( $wgContLang->ucfirst( $term ) );
if ( $title->exists() ) {
return $title;
}
$title = Title::newFromText( $wgContLang->lcfirst( $term ) );
if ( $title->exists() ) {
return $title;
}
}
// Give hooks a chance at better match variants
$title = null;
if( !wfRunHooks( 'SearchGetNearMatch', array( $term, &$title ) ) ) {
return $title;
}
}
$title = Title::newFromText( $searchterm );
# Entering an IP address goes to the contributions page
if ( ( $title->getNamespace() == NS_USER && User::isIP($title->getText() ) )
|| User::isIP( trim( $searchterm ) ) ) {
return SpecialPage::getTitleFor( 'Contributions', $title->getDBkey() );
}
# Entering a user goes to the user page whether it's there or not
if ( $title->getNamespace() == NS_USER ) {
return $title;
}
# Go to images that exist even if there's no local page.
# There may have been a funny upload, or it may be on a shared
# file repository such as Wikimedia Commons.
if( $title->getNamespace() == NS_IMAGE ) {
$image = wfFindFile( $title );
if( $image ) {
return $title;
}
}
# MediaWiki namespace? Page may be "implied" if not customized.
# Just return it, with caps forced as the message system likes it.
if( $title->getNamespace() == NS_MEDIAWIKI ) {
return Title::makeTitle( NS_MEDIAWIKI, $wgContLang->ucfirst( $title->getText() ) );
}
# Quoted term? Try without the quotes...
$matches = array();
if( preg_match( '/^"([^"]+)"$/', $searchterm, $matches ) ) {
return SearchEngine::getNearMatch( $matches[1] );
}
return NULL;
}
public static function legalSearchChars() {
return "A-Za-z_'0-9\\x80-\\xFF\\-";
}
/**
* Set the maximum number of results to return
* and how many to skip before returning the first.
*
* @param int $limit
* @param int $offset
* @access public
*/
function setLimitOffset( $limit, $offset = 0 ) {
$this->limit = intval( $limit );
$this->offset = intval( $offset );
}
/**
* Set which namespaces the search should include.
* Give an array of namespace index numbers.
*
* @param array $namespaces
* @access public
*/
function setNamespaces( $namespaces ) {
$this->namespaces = $namespaces;
}
/**
* Parse some common prefixes: all (search everything)
* or namespace names
*
* @param string $query
*/
function replacePrefixes( $query ){
global $wgContLang;
if( strpos($query,':') === false )
return $query; // nothing to do
$parsed = $query;
$allkeyword = wfMsgForContent('searchall').":";
if( strncmp($query, $allkeyword, strlen($allkeyword)) == 0 ){
$this->namespaces = null;
$parsed = substr($query,strlen($allkeyword));
} else if( strpos($query,':') !== false ) {
$prefix = substr($query,0,strpos($query,':'));
$index = $wgContLang->getNsIndex($prefix);
if($index !== false){
$this->namespaces = array($index);
$parsed = substr($query,strlen($prefix)+1);
}
}
if(trim($parsed) == '')
return $query; // prefix was the whole query
return $parsed;
}
/**
* Make a list of searchable namespaces and their canonical names.
* @return array
*/
public static function searchableNamespaces() {
global $wgContLang;
$arr = array();
foreach( $wgContLang->getNamespaces() as $ns => $name ) {
if( $ns >= NS_MAIN ) {
$arr[$ns] = $name;
}
}
return $arr;
}
/**
* Extract default namespaces to search from the given user's
* settings, returning a list of index numbers.
*
* @param User $user
* @return array
* @static
*/
public static function userNamespaces( &$user ) {
$arr = array();
foreach( SearchEngine::searchableNamespaces() as $ns => $name ) {
if( $user->getOption( 'searchNs' . $ns ) ) {
$arr[] = $ns;
}
}
return $arr;
}
/**
* Find snippet highlight settings for a given user
*
* @param User $user
* @return array contextlines, contextchars
* @static
*/
public static function userHighlightPrefs( &$user ){
//$contextlines = $user->getOption( 'contextlines', 5 );
$contextlines = 2; // Hardcode this. Old defaults sucked. :)
$contextchars = $user->getOption( 'contextchars', 50 );
return array($contextlines, $contextchars);
}
/**
* An array of namespaces indexes to be searched by default
*
* @return array
* @static
*/
public static function defaultNamespaces(){
global $wgNamespacesToBeSearchedDefault;
return array_keys($wgNamespacesToBeSearchedDefault, true);
}
/**
* Return a 'cleaned up' search string
*
* @return string
* @access public
*/
function filter( $text ) {
$lc = $this->legalSearchChars();
return trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
}
/**
* Load up the appropriate search engine class for the currently
* active database backend, and return a configured instance.
*
* @return SearchEngine
*/
public static function create() {
global $wgDBtype, $wgSearchType;
if( $wgSearchType ) {
$class = $wgSearchType;
} elseif( $wgDBtype == 'mysql' ) {
$class = 'SearchMySQL';
} else if ( $wgDBtype == 'postgres' ) {
$class = 'SearchPostgres';
} else if ( $wgDBtype == 'oracle' ) {
$class = 'SearchOracle';
} else {
$class = 'SearchEngineDummy';
}
$search = new $class( wfGetDB( DB_SLAVE ) );
$search->setLimitOffset(0,0);
return $search;
}
/**
* Create or update the search index record for the given page.
* Title and text should be pre-processed.
*
* @param int $id
* @param string $title
* @param string $text
* @abstract
*/
function update( $id, $title, $text ) {
// no-op
}
/**
* Update a search index record's title only.
* Title should be pre-processed.
*
* @param int $id
* @param string $title
* @abstract
*/
function updateTitle( $id, $title ) {
// no-op
}
/**
* Get OpenSearch suggestion template
*
* @return string
* @static
*/
public static function getOpenSearchTemplate() {
global $wgOpenSearchTemplate, $wgServer, $wgScriptPath;
if($wgOpenSearchTemplate)
return $wgOpenSearchTemplate;
else{
$ns = implode(',',SearchEngine::defaultNamespaces());
if(!$ns) $ns = "0";
return $wgServer . $wgScriptPath . '/api.php?action=opensearch&search={searchTerms}&namespace='.$ns;
}
}
/**
* Get internal MediaWiki Suggest template
*
* @return string
* @static
*/
public static function getMWSuggestTemplate() {
global $wgMWSuggestTemplate, $wgServer, $wgScriptPath;
if($wgMWSuggestTemplate)
return $wgMWSuggestTemplate;
else
return $wgServer . $wgScriptPath . '/api.php?action=opensearch&search={searchTerms}&namespace={namespaces}';
}
}
/**
* @addtogroup Search
*/
class SearchResultSet {
/**
* Fetch an array of regular expression fragments for matching
* the search terms as parsed by this engine in a text extract.
*
* @return array
* @access public
* @abstract
*/
function termMatches() {
return array();
}
function numRows() {
return 0;
}
/**
* Return true if results are included in this result set.
* @return bool
* @abstract
*/
function hasResults() {
return false;
}
/**
* Some search modes return a total hit count for the query
* in the entire article database. This may include pages
* in namespaces that would not be matched on the given
* settings.
*
* Return null if no total hits number is supported.
*
* @return int
* @access public
*/
function getTotalHits() {
return null;
}
/**
* Some search modes return a suggested alternate term if there are
* no exact hits. Returns true if there is one on this set.
*
* @return bool
* @access public
*/
function hasSuggestion() {
return false;
}
/**
* @return string suggested query, null if none
*/
function getSuggestionQuery(){
return null;
}
/**
* @return string highlighted suggested query, '' if none
*/
function getSuggestionSnippet(){
return '';
}
/**
* Return information about how and from where the results were fetched,
* should be useful for diagnostics and debugging
*
* @return string
*/
function getInfo() {
return null;
}
/**
* Return a result set of hits on other (multiple) wikis associated with this one
*
* @return SearchResultSet
*/
function getInterwikiResults() {
return null;
}
/**
* Check if there are results on other wikis
*
* @return boolean
*/
function hasInterwikiResults() {
return $this->getInterwikiResults() != null;
}
/**
* Fetches next search result, or false.
* @return SearchResult
* @access public
* @abstract
*/
function next() {
return false;
}
/**
* Frees the result set, if applicable.
* @ access public
*/
function free() {
// ...
}
}
/**
* @addtogroup Search
*/
class SearchResultTooMany {
## Some search engines may bail out if too many matches are found
}
/**
* @addtogroup Search
*/
class SearchResult {
function SearchResult( $row ) {
$this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
if( !is_null($this->mTitle) )
$this->mRevision = Revision::newFromTitle( $this->mTitle );
}
/**
* Check if this is result points to an invalid title
*
* @return boolean
* @access public
*/
function isBrokenTitle(){
if( is_null($this->mTitle) )
return true;
return false;
}
/**
* Check if target page is missing, happens when index is out of date
*
* @return boolean
* @access public
*/
function isMissingRevision(){
if( !$this->mRevision )
return true;
return false;
}
/**
* @return Title
* @access public
*/
function getTitle() {
return $this->mTitle;
}
/**
* @return double or null if not supported
*/
function getScore() {
return null;
}
/**
* Lazy initialization of article text from DB
*/
protected function initText(){
if( !isset($this->mText) ){
$this->mText = $this->mRevision->getText();
}
}
/**
* @param array $terms Terms to highlight (unescaped)
* @return string highlighted text snippet, null (and not '') if not supported
*/
function getTextSnippet($terms){
global $wgUser;
$this->initText();
list($contextlines,$contextchars) = SearchEngine::userHighlightPrefs($wgUser);
return $this->extractText( $this->mText, $terms, $contextlines, $contextchars);
}
/**
* Default implementation of snippet extraction
*
* @param string $text
* @param array $terms Terms to highlight (unescaped)
* @param int $contextlines
* @param int $contextchars
* @return string
*/
protected function extractText( $text, $terms, $contextlines, $contextchars ) {
global $wgLang, $wgContLang;
$fname = __METHOD__;
$lines = explode( "\n", $text );
foreach( $terms as $index => $term ) {
$terms[$index] = preg_quote( $term, '/' );
}
$terms = implode( '|', $terms );
$max = intval( $contextchars ) + 1;
$pat1 = "/(.*)($terms)(.{0,$max})/i";
$lineno = 0;
$extract = "";
wfProfileIn( "$fname-extract" );
foreach ( $lines as $line ) {
if ( 0 == $contextlines ) {
break;
}
++$lineno;
$m = array();
if ( ! preg_match( $pat1, $line, $m ) ) {
continue;
}
--$contextlines;
$pre = $wgContLang->truncate( $m[1], -$contextchars, ' ... ' );
if ( count( $m ) < 3 ) {
$post = '';
} else {
$post = $wgContLang->truncate( $m[3], $contextchars, ' ... ' );
}
$found = $m[2];
$line = htmlspecialchars( $pre . $found . $post );
$pat2 = '/(' . $terms . ")/i";
$line = preg_replace( $pat2,
"<span class='searchmatch'>\\1</span>", $line );
$extract .= "${line}\n";
}
wfProfileOut( "$fname-extract" );
return $extract;
}
/**
* @param array $terms terms to highlight
* @return string highlighted title, '' if not supported
*/
function getTitleSnippet($terms){
return '';
}
/**
* @param array $terms terms to highlight
* @return string highlighted redirect name (redirect to this page), '' if none or not supported
*/
function getRedirectSnippet($terms){
return '';
}
/**
* @return Title object for the redirect to this page, null if none or not supported
*/
function getRedirectTitle(){
return null;
}
/**
* @return string highlighted relevant section name, null if none or not supported
*/
function getSectionSnippet(){
return '';
}
/**
* @return Title object (pagename+fragment) for the section, null if none or not supported
*/
function getSectionTitle(){
return null;
}
/**
* @return string timestamp
*/
function getTimestamp(){
return $this->mRevision->getTimestamp();
}
/**
* @return int number of words
*/
function getWordCount(){
$this->initText();
return str_word_count( $this->mText );
}
/**
* @return int size in bytes
*/
function getByteSize(){
$this->initText();
return strlen( $this->mText );
}
/**
* @return boolean if hit has related articles
*/
function hasRelated(){
return false;
}
/**
* @return interwiki prefix of the title (return iw even if title is broken)
*/
function getInterwikiPrefix(){
return '';
}
}
/**
* @addtogroup Search
*/
class SearchEngineDummy {
function search( $term ) {
return null;
}
function setLimitOffset($l, $o) {}
function legalSearchChars() {}
function update() {}
function setnamespaces() {}
function searchtitle() {}
function searchtext() {}
}