drupal/modules/search/search.module

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<?php
// $Id$
/**
* @file
* Enables site-wide keyword searching.
*/
/**
* Matches Unicode character classes to exclude from the search index.
*
* See: http://www.unicode.org/Public/UNIDATA/UCD.html#General_Category_Values
*
* The index only contains the following character classes:
* Lu Letter, Uppercase
* Ll Letter, Lowercase
* Lt Letter, Titlecase
* Lo Letter, Other
* Nd Number, Decimal Digit
* No Number, Other
*/
define('PREG_CLASS_SEARCH_EXCLUDE',
'\x{0}-\x{2f}\x{3a}-\x{40}\x{5b}-\x{60}\x{7b}-\x{bf}\x{d7}\x{f7}\x{2b0}-' .
'\x{385}\x{387}\x{3f6}\x{482}-\x{489}\x{559}-\x{55f}\x{589}-\x{5c7}\x{5f3}-' .
'\x{61f}\x{640}\x{64b}-\x{65e}\x{66a}-\x{66d}\x{670}\x{6d4}\x{6d6}-\x{6ed}' .
'\x{6fd}\x{6fe}\x{700}-\x{70f}\x{711}\x{730}-\x{74a}\x{7a6}-\x{7b0}\x{901}-' .
'\x{903}\x{93c}\x{93e}-\x{94d}\x{951}-\x{954}\x{962}-\x{965}\x{970}\x{981}-' .
'\x{983}\x{9bc}\x{9be}-\x{9cd}\x{9d7}\x{9e2}\x{9e3}\x{9f2}-\x{a03}\x{a3c}-' .
'\x{a4d}\x{a70}\x{a71}\x{a81}-\x{a83}\x{abc}\x{abe}-\x{acd}\x{ae2}\x{ae3}' .
'\x{af1}-\x{b03}\x{b3c}\x{b3e}-\x{b57}\x{b70}\x{b82}\x{bbe}-\x{bd7}\x{bf0}-' .
'\x{c03}\x{c3e}-\x{c56}\x{c82}\x{c83}\x{cbc}\x{cbe}-\x{cd6}\x{d02}\x{d03}' .
'\x{d3e}-\x{d57}\x{d82}\x{d83}\x{dca}-\x{df4}\x{e31}\x{e34}-\x{e3f}\x{e46}-' .
'\x{e4f}\x{e5a}\x{e5b}\x{eb1}\x{eb4}-\x{ebc}\x{ec6}-\x{ecd}\x{f01}-\x{f1f}' .
'\x{f2a}-\x{f3f}\x{f71}-\x{f87}\x{f90}-\x{fd1}\x{102c}-\x{1039}\x{104a}-' .
'\x{104f}\x{1056}-\x{1059}\x{10fb}\x{10fc}\x{135f}-\x{137c}\x{1390}-\x{1399}' .
'\x{166d}\x{166e}\x{1680}\x{169b}\x{169c}\x{16eb}-\x{16f0}\x{1712}-\x{1714}' .
'\x{1732}-\x{1736}\x{1752}\x{1753}\x{1772}\x{1773}\x{17b4}-\x{17db}\x{17dd}' .
'\x{17f0}-\x{180e}\x{1843}\x{18a9}\x{1920}-\x{1945}\x{19b0}-\x{19c0}\x{19c8}' .
'\x{19c9}\x{19de}-\x{19ff}\x{1a17}-\x{1a1f}\x{1d2c}-\x{1d61}\x{1d78}\x{1d9b}-' .
'\x{1dc3}\x{1fbd}\x{1fbf}-\x{1fc1}\x{1fcd}-\x{1fcf}\x{1fdd}-\x{1fdf}\x{1fed}-' .
'\x{1fef}\x{1ffd}-\x{2070}\x{2074}-\x{207e}\x{2080}-\x{2101}\x{2103}-\x{2106}' .
'\x{2108}\x{2109}\x{2114}\x{2116}-\x{2118}\x{211e}-\x{2123}\x{2125}\x{2127}' .
'\x{2129}\x{212e}\x{2132}\x{213a}\x{213b}\x{2140}-\x{2144}\x{214a}-\x{2b13}' .
'\x{2ce5}-\x{2cff}\x{2d6f}\x{2e00}-\x{3005}\x{3007}-\x{303b}\x{303d}-\x{303f}' .
'\x{3099}-\x{309e}\x{30a0}\x{30fb}-\x{30fe}\x{3190}-\x{319f}\x{31c0}-\x{31cf}' .
'\x{3200}-\x{33ff}\x{4dc0}-\x{4dff}\x{a015}\x{a490}-\x{a716}\x{a802}\x{a806}' .
'\x{a80b}\x{a823}-\x{a82b}\x{d800}-\x{f8ff}\x{fb1e}\x{fb29}\x{fd3e}\x{fd3f}' .
'\x{fdfc}-\x{fe6b}\x{feff}-\x{ff0f}\x{ff1a}-\x{ff20}\x{ff3b}-\x{ff40}\x{ff5b}-' .
'\x{ff65}\x{ff70}\x{ff9e}\x{ff9f}\x{ffe0}-\x{fffd}');
/**
* Matches all 'N' Unicode character classes (numbers)
*/
define('PREG_CLASS_NUMBERS',
'\x{30}-\x{39}\x{b2}\x{b3}\x{b9}\x{bc}-\x{be}\x{660}-\x{669}\x{6f0}-\x{6f9}'.
'\x{966}-\x{96f}\x{9e6}-\x{9ef}\x{9f4}-\x{9f9}\x{a66}-\x{a6f}\x{ae6}-\x{aef}'.
'\x{b66}-\x{b6f}\x{be7}-\x{bf2}\x{c66}-\x{c6f}\x{ce6}-\x{cef}\x{d66}-\x{d6f}'.
'\x{e50}-\x{e59}\x{ed0}-\x{ed9}\x{f20}-\x{f33}\x{1040}-\x{1049}\x{1369}-'.
'\x{137c}\x{16ee}-\x{16f0}\x{17e0}-\x{17e9}\x{17f0}-\x{17f9}\x{1810}-\x{1819}'.
'\x{1946}-\x{194f}\x{2070}\x{2074}-\x{2079}\x{2080}-\x{2089}\x{2153}-\x{2183}'.
'\x{2460}-\x{249b}\x{24ea}-\x{24ff}\x{2776}-\x{2793}\x{3007}\x{3021}-\x{3029}'.
'\x{3038}-\x{303a}\x{3192}-\x{3195}\x{3220}-\x{3229}\x{3251}-\x{325f}\x{3280}-'.
'\x{3289}\x{32b1}-\x{32bf}\x{ff10}-\x{ff19}');
/**
* Matches all 'P' Unicode character classes (punctuation)
*/
define('PREG_CLASS_PUNCTUATION',
'\x{21}-\x{23}\x{25}-\x{2a}\x{2c}-\x{2f}\x{3a}\x{3b}\x{3f}\x{40}\x{5b}-\x{5d}'.
'\x{5f}\x{7b}\x{7d}\x{a1}\x{ab}\x{b7}\x{bb}\x{bf}\x{37e}\x{387}\x{55a}-\x{55f}'.
'\x{589}\x{58a}\x{5be}\x{5c0}\x{5c3}\x{5f3}\x{5f4}\x{60c}\x{60d}\x{61b}\x{61f}'.
'\x{66a}-\x{66d}\x{6d4}\x{700}-\x{70d}\x{964}\x{965}\x{970}\x{df4}\x{e4f}'.
'\x{e5a}\x{e5b}\x{f04}-\x{f12}\x{f3a}-\x{f3d}\x{f85}\x{104a}-\x{104f}\x{10fb}'.
'\x{1361}-\x{1368}\x{166d}\x{166e}\x{169b}\x{169c}\x{16eb}-\x{16ed}\x{1735}'.
'\x{1736}\x{17d4}-\x{17d6}\x{17d8}-\x{17da}\x{1800}-\x{180a}\x{1944}\x{1945}'.
'\x{2010}-\x{2027}\x{2030}-\x{2043}\x{2045}-\x{2051}\x{2053}\x{2054}\x{2057}'.
'\x{207d}\x{207e}\x{208d}\x{208e}\x{2329}\x{232a}\x{23b4}-\x{23b6}\x{2768}-'.
'\x{2775}\x{27e6}-\x{27eb}\x{2983}-\x{2998}\x{29d8}-\x{29db}\x{29fc}\x{29fd}'.
'\x{3001}-\x{3003}\x{3008}-\x{3011}\x{3014}-\x{301f}\x{3030}\x{303d}\x{30a0}'.
'\x{30fb}\x{fd3e}\x{fd3f}\x{fe30}-\x{fe52}\x{fe54}-\x{fe61}\x{fe63}\x{fe68}'.
'\x{fe6a}\x{fe6b}\x{ff01}-\x{ff03}\x{ff05}-\x{ff0a}\x{ff0c}-\x{ff0f}\x{ff1a}'.
'\x{ff1b}\x{ff1f}\x{ff20}\x{ff3b}-\x{ff3d}\x{ff3f}\x{ff5b}\x{ff5d}\x{ff5f}-'.
'\x{ff65}');
/**
* Matches all CJK characters that are candidates for auto-splitting
* (Chinese, Japanese, Korean).
* Contains kana and BMP ideographs.
*/
define('PREG_CLASS_CJK', '\x{3041}-\x{30ff}\x{31f0}-\x{31ff}\x{3400}-\x{4db5}' .
'\x{4e00}-\x{9fbb}\x{f900}-\x{fad9}');
/**
* Implementation of hook_help().
*/
function search_help($path, $arg) {
switch ($path) {
case 'admin/help#search':
$output = '<p>' . t('The search module adds the ability to search for content by keywords. Search is often the only practical way to find content on a large site, and is useful for finding both users and posts.') . '</p>';
$output .= '<p>' . t('To provide keyword searching, the search engine maintains an index of words found in your site\'s content. To build and maintain this index, a correctly configured <a href="@cron">cron maintenance task</a> is required. Indexing behavior can be adjusted using the <a href="@searchsettings">search settings page</a>; for example, the <em>Number of items to index per cron run</em> sets the maximum number of items indexed in each pass of a <a href="@cron">cron maintenance task</a>. If necessary, reduce this number to prevent timeouts and memory errors when indexing.', array('@cron' => url('admin/reports/status'), '@searchsettings' => url('admin/settings/search'))) . '</p>';
$output .= '<p>' . t('For more information, see the online handbook entry for <a href="@search">Search module</a>.', array('@search' => 'http://drupal.org/handbook/modules/search/')) . '</p>';
return $output;
case 'admin/settings/search':
return '<p>' . t('The search engine maintains an index of words found in your site\'s content. To build and maintain this index, a correctly configured <a href="@cron">cron maintenance task</a> is required. Indexing behavior can be adjusted using the settings below.', array('@cron' => url('admin/reports/status'))) . '</p>';
case 'search#noresults':
return t('<ul>
<li>Check if your spelling is correct.</li>
<li>Remove quotes around phrases to search for each word individually. <em>bike shed</em> will often show more results than <em>&quot;bike shed&quot;</em>.</li>
<li>Consider loosening your query with <em>OR</em>. <em>bike OR shed</em> will often show more results than <em>bike shed</em>.</li>
</ul>');
}
}
/**
* Implementation of hook_theme().
*/
function search_theme() {
return array(
'search_theme_form' => array(
'arguments' => array('form' => NULL),
'template' => 'search-theme-form',
),
'search_block_form' => array(
'arguments' => array('form' => NULL),
'template' => 'search-block-form',
),
'search_result' => array(
'arguments' => array('result' => NULL, 'type' => NULL),
'file' => 'search.pages.inc',
'template' => 'search-result',
),
'search_results' => array(
'arguments' => array('results' => NULL, 'type' => NULL),
'file' => 'search.pages.inc',
'template' => 'search-results',
),
);
}
/**
* Implementation of hook_perm().
*/
function search_perm() {
return array(
'administer search' => array(
'title' => t('Administer search'),
'description' => t('Configure search administration settings.'),
),
'search content' => array(
'title' => t('Search content'),
'description' => t('Search website content.'),
),
'use advanced search' => array(
'title' => t('Use advanced search'),
'description' => t('Limit search results with additional criteria, such as specific content types. Could have performance implications.'),
),
);
}
/**
* Implementation of hook_block().
*/
function search_block($op = 'list', $delta = '') {
if ($op == 'list') {
$blocks['form']['info'] = t('Search form');
// Not worth caching.
$blocks['form']['cache'] = BLOCK_NO_CACHE;
return $blocks;
}
elseif ($op == 'view' && user_access('search content')) {
$block['content'] = drupal_get_form('search_block_form');
$block['subject'] = t('Search');
return $block;
}
}
/**
* Implementation of hook_menu().
*/
function search_menu() {
$items['search'] = array(
'title' => 'Search',
'page callback' => 'search_view',
'access arguments' => array('search content'),
'type' => MENU_SUGGESTED_ITEM,
);
$items['admin/settings/search'] = array(
'title' => 'Search settings',
'description' => 'Configure relevance settings for search and other indexing options',
'page callback' => 'drupal_get_form',
'page arguments' => array('search_admin_settings'),
'access arguments' => array('administer search'),
'type' => MENU_NORMAL_ITEM,
);
$items['admin/settings/search/wipe'] = array(
'title' => 'Clear index',
'page callback' => 'drupal_get_form',
'page arguments' => array('search_wipe_confirm'),
'access arguments' => array('administer search'),
'type' => MENU_CALLBACK,
);
$items['admin/reports/search'] = array(
'title' => 'Top search phrases',
'description' => 'View most popular search phrases.',
'page callback' => 'dblog_top',
'page arguments' => array('search'),
'access arguments' => array('access site reports'),
'file path' => drupal_get_path('module', 'dblog'),
);
foreach (module_implements('search') as $module) {
$items['search/' . $module . '/%menu_tail'] = array(
'title callback' => 'module_invoke',
'title arguments' => array($module, 'search', 'name', TRUE),
'page callback' => 'search_view',
'page arguments' => array($module),
'access callback' => '_search_menu',
'access arguments' => array($module),
'type' => MENU_LOCAL_TASK,
'parent' => 'search',
);
}
return $items;
}
function _search_menu($name) {
return user_access('search content') && module_invoke($name, 'search', 'name');
}
/**
* Wipes a part of or the entire search index.
*
* @param $sid
* (optional) The SID of the item to wipe. If specified, $type must be passed
* too.
* @param $type
* (optional) The type of item to wipe.
*/
function search_wipe($sid = NULL, $type = NULL, $reindex = FALSE) {
if ($type == NULL && $sid == NULL) {
module_invoke_all('search', 'reset');
}
else {
db_query("DELETE FROM {search_dataset} WHERE sid = %d AND type = '%s'", $sid, $type);
db_query("DELETE FROM {search_index} WHERE sid = %d AND type = '%s'", $sid, $type);
// Don't remove links if re-indexing.
if (!$reindex) {
db_query("DELETE FROM {search_node_links} WHERE sid = %d AND type = '%s'", $sid, $type);
}
}
}
/**
* Marks a word as dirty (or retrieves the list of dirty words). This is used
* during indexing (cron). Words which are dirty have outdated total counts in
* the search_total table, and need to be recounted.
*/
function search_dirty($word = NULL) {
static $dirty = array();
if ($word !== NULL) {
$dirty[$word] = TRUE;
}
else {
return $dirty;
}
}
/**
* Implementation of hook_cron().
*
* Fires hook_update_index() in all modules and cleans up dirty words (see
* search_dirty).
*/
function search_cron() {
// We register a shutdown function to ensure that search_total is always up
// to date.
register_shutdown_function('search_update_totals');
// Update word index
foreach (module_implements('update_index') as $module) {
$function = $module . '_update_index';
$function();
}
}
/**
* This function is called on shutdown to ensure that search_total is always
* up to date (even if cron times out or otherwise fails).
*/
function search_update_totals() {
// Update word IDF (Inverse Document Frequency) counts for new/changed words
foreach (search_dirty() as $word => $dummy) {
// Get total count
$total = db_result(db_query("SELECT SUM(score) FROM {search_index} WHERE word = '%s'", $word));
// Apply Zipf's law to equalize the probability distribution
$total = log10(1 + 1/(max(1, $total)));
db_merge('search_total')->key(array('word' => $word))->fields(array('count' => $total))->execute();
}
// Find words that were deleted from search_index, but are still in
// search_total. We use a LEFT JOIN between the two tables and keep only the
// rows which fail to join.
$result = db_query("SELECT t.word AS realword, i.word FROM {search_total} t LEFT JOIN {search_index} i ON t.word = i.word WHERE i.word IS NULL");
while ($word = db_fetch_object($result)) {
db_query("DELETE FROM {search_total} WHERE word = '%s'", $word->realword);
}
}
/**
* Simplifies a string according to indexing rules.
*/
function search_simplify($text) {
// Decode entities to UTF-8
$text = decode_entities($text);
// Lowercase
$text = drupal_strtolower($text);
// Call an external processor for word handling.
search_invoke_preprocess($text);
// Simple CJK handling
if (variable_get('overlap_cjk', TRUE)) {
$text = preg_replace_callback('/[' . PREG_CLASS_CJK . ']+/u', 'search_expand_cjk', $text);
}
// To improve searching for numerical data such as dates, IP addresses
// or version numbers, we consider a group of numerical characters
// separated only by punctuation characters to be one piece.
// This also means that searching for e.g. '20/03/1984' also returns
// results with '20-03-1984' in them.
// Readable regexp: ([number]+)[punctuation]+(?=[number])
$text = preg_replace('/([' . PREG_CLASS_NUMBERS . ']+)[' . PREG_CLASS_PUNCTUATION . ']+(?=[' . PREG_CLASS_NUMBERS . '])/u', '\1', $text);
// The dot, underscore and dash are simply removed. This allows meaningful
// search behavior with acronyms and URLs.
$text = preg_replace('/[._-]+/', '', $text);
// With the exception of the rules above, we consider all punctuation,
// marks, spacers, etc, to be a word boundary.
$text = preg_replace('/[' . PREG_CLASS_SEARCH_EXCLUDE . ']+/u', ' ', $text);
return $text;
}
/**
* Basic CJK tokenizer. Simply splits a string into consecutive, overlapping
* sequences of characters ('minimum_word_size' long).
*/
function search_expand_cjk($matches) {
$min = variable_get('minimum_word_size', 3);
$str = $matches[0];
$l = drupal_strlen($str);
// Passthrough short words
if ($l <= $min) {
return ' ' . $str . ' ';
}
$tokens = ' ';
// FIFO queue of characters
$chars = array();
// Begin loop
for ($i = 0; $i < $l; ++$i) {
// Grab next character
$current = drupal_substr($str, 0, 1);
$str = substr($str, strlen($current));
$chars[] = $current;
if ($i >= $min - 1) {
$tokens .= implode('', $chars) . ' ';
array_shift($chars);
}
}
return $tokens;
}
/**
* Splits a string into tokens for indexing.
*/
function search_index_split($text) {
static $last = NULL;
static $lastsplit = NULL;
if ($last == $text) {
return $lastsplit;
}
// Process words
$text = search_simplify($text);
$words = explode(' ', $text);
array_walk($words, '_search_index_truncate');
// Save last keyword result
$last = $text;
$lastsplit = $words;
return $words;
}
/**
* Helper function for array_walk in search_index_split.
*/
function _search_index_truncate(&$text) {
$text = truncate_utf8($text, 50);
}
/**
* Invokes hook_search_preprocess() in modules.
*/
function search_invoke_preprocess(&$text) {
foreach (module_implements('search_preprocess') as $module) {
$text = module_invoke($module, 'search_preprocess', $text);
}
}
/**
* Update the full-text search index for a particular item.
*
* @param $sid
* A number identifying this particular item (e.g. node id).
*
* @param $type
* A string defining this type of item (e.g. 'node')
*
* @param $text
* The content of this item. Must be a piece of HTML text.
*
* @ingroup search
*/
function search_index($sid, $type, $text) {
$minimum_word_size = variable_get('minimum_word_size', 3);
// Link matching
global $base_url;
$node_regexp = '@href=[\'"]?(?:' . preg_quote($base_url, '@') . '/|' . preg_quote(base_path(), '@') . ')(?:\?q=)?/?((?![a-z]+:)[^\'">]+)[\'">]@i';
// Multipliers for scores of words inside certain HTML tags. The weights are stored
// in a variable so that modules can overwrite the default weights.
// Note: 'a' must be included for link ranking to work.
$tags = variable_get('search_tag_weights', array(
'h1' => 25,
'h2' => 18,
'h3' => 15,
'h4' => 12,
'h5' => 9,
'h6' => 6,
'u' => 3,
'b' => 3,
'i' => 3,
'strong' => 3,
'em' => 3,
'a' => 10));
// Strip off all ignored tags to speed up processing, but insert space before/after
// them to keep word boundaries.
$text = str_replace(array('<', '>'), array(' <', '> '), $text);
$text = strip_tags($text, '<' . implode('><', array_keys($tags)) . '>');
// Split HTML tags from plain text.
$split = preg_split('/\s*<([^>]+?)>\s*/', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
// Note: PHP ensures the array consists of alternating delimiters and literals
// and begins and ends with a literal (inserting $null as required).
$tag = FALSE; // Odd/even counter. Tag or no tag.
$link = FALSE; // State variable for link analyser
$score = 1; // Starting score per word
$accum = ' '; // Accumulator for cleaned up data
$tagstack = array(); // Stack with open tags
$tagwords = 0; // Counter for consecutive words
$focus = 1; // Focus state
$results = array(0 => array()); // Accumulator for words for index
foreach ($split as $value) {
if ($tag) {
// Increase or decrease score per word based on tag
list($tagname) = explode(' ', $value, 2);
$tagname = drupal_strtolower($tagname);
// Closing or opening tag?
if ($tagname[0] == '/') {
$tagname = substr($tagname, 1);
// If we encounter unexpected tags, reset score to avoid incorrect boosting.
if (!count($tagstack) || $tagstack[0] != $tagname) {
$tagstack = array();
$score = 1;
}
else {
// Remove from tag stack and decrement score
$score = max(1, $score - $tags[array_shift($tagstack)]);
}
if ($tagname == 'a') {
$link = FALSE;
}
}
else {
if (isset($tagstack[0]) && $tagstack[0] == $tagname) {
// None of the tags we look for make sense when nested identically.
// If they are, it's probably broken HTML.
$tagstack = array();
$score = 1;
}
else {
// Add to open tag stack and increment score
array_unshift($tagstack, $tagname);
$score += $tags[$tagname];
}
if ($tagname == 'a') {
// Check if link points to a node on this site
if (preg_match($node_regexp, $value, $match)) {
$path = drupal_get_normal_path($match[1]);
if (preg_match('!(?:node|book)/(?:view/)?([0-9]+)!i', $path, $match)) {
$linknid = $match[1];
if ($linknid > 0) {
// Note: ignore links to uncachable nodes to avoid redirect bugs.
$node = db_fetch_object(db_query('SELECT n.title, n.nid, n.vid, r.format FROM {node} n INNER JOIN {node_revision} r ON n.vid = r.vid WHERE n.nid = %d', $linknid));
if (filter_format_allowcache($node->format)) {
$link = TRUE;
$linktitle = $node->title;
}
}
}
}
}
}
// A tag change occurred, reset counter.
$tagwords = 0;
}
else {
// Note: use of PREG_SPLIT_DELIM_CAPTURE above will introduce empty values
if ($value != '') {
if ($link) {
// Check to see if the node link text is its URL. If so, we use the target node title instead.
if (preg_match('!^https?://!i', $value)) {
$value = $linktitle;
}
}
$words = search_index_split($value);
foreach ($words as $word) {
// Add word to accumulator
$accum .= $word . ' ';
$num = is_numeric($word);
// Check wordlength
if ($num || drupal_strlen($word) >= $minimum_word_size) {
// Normalize numbers
if ($num) {
$word = (int)ltrim($word, '-0');
}
// Links score mainly for the target.
if ($link) {
if (!isset($results[$linknid])) {
$results[$linknid] = array();
}
$results[$linknid][] = $word;
// Reduce score of the link caption in the source.
$focus *= 0.2;
}
// Fall-through
if (!isset($results[0][$word])) {
$results[0][$word] = 0;
}
$results[0][$word] += $score * $focus;
// Focus is a decaying value in terms of the amount of unique words up to this point.
// From 100 words and more, it decays, to e.g. 0.5 at 500 words and 0.3 at 1000 words.
$focus = min(1, .01 + 3.5 / (2 + count($results[0]) * .015));
}
$tagwords++;
// Too many words inside a single tag probably mean a tag was accidentally left open.
if (count($tagstack) && $tagwords >= 15) {
$tagstack = array();
$score = 1;
}
}
}
}
$tag = !$tag;
}
search_wipe($sid, $type, TRUE);
// Insert cleaned up data into dataset
db_query("INSERT INTO {search_dataset} (sid, type, data, reindex) VALUES (%d, '%s', '%s', %d)", $sid, $type, $accum, 0);
// Insert results into search index
foreach ($results[0] as $word => $score) {
// If a word already exists in the database, its score gets increased
// appropriately. If not, we create a new record with the appropriate
// starting score.
db_merge('search_index')->key(array(
'word' => $word,
'sid' => $sid,
'type' => $type,
))->fields(array('score' => $score))->expression('score', 'score + :score', array(':score' => $score))
->execute();
search_dirty($word);
}
unset($results[0]);
// Get all previous links from this item.
$result = db_query("SELECT nid, caption FROM {search_node_links} WHERE sid = %d AND type = '%s'", $sid, $type);
$links = array();
while ($link = db_fetch_object($result)) {
$links[$link->nid] = $link->caption;
}
// Now store links to nodes.
foreach ($results as $nid => $words) {
$caption = implode(' ', $words);
if (isset($links[$nid])) {
if ($links[$nid] != $caption) {
// Update the existing link and mark the node for reindexing.
db_query("UPDATE {search_node_links} SET caption = '%s' WHERE sid = %d AND type = '%s' AND nid = %d", $caption, $sid, $type, $nid);
search_touch_node($nid);
}
// Unset the link to mark it as processed.
unset($links[$nid]);
}
else {
// Insert the existing link and mark the node for reindexing.
db_query("INSERT INTO {search_node_links} (caption, sid, type, nid) VALUES ('%s', %d, '%s', %d)", $caption, $sid, $type, $nid);
search_touch_node($nid);
}
}
// Any left-over links in $links no longer exist. Delete them and mark the nodes for reindexing.
foreach ($links as $nid => $caption) {
db_query("DELETE FROM {search_node_links} WHERE sid = %d AND type = '%s' AND nid = %d", $sid, $type, $nid);
search_touch_node($nid);
}
}
/**
* Change a node's changed timestamp to 'now' to force reindexing.
*
* @param $nid
* The nid of the node that needs reindexing.
*/
function search_touch_node($nid) {
db_query("UPDATE {search_dataset} SET reindex = %d WHERE sid = %d AND type = 'node'", REQUEST_TIME, $nid);
}
/**
* Implementation of hook_nodeapi_update_index().
*/
function search_nodeapi_update_index($node) {
// Transplant links to a node into the target node.
$result = db_query("SELECT caption FROM {search_node_links} WHERE nid = %d", $node->nid);
$output = array();
while ($link = db_fetch_object($result)) {
$output[] = $link->caption;
}
return '<a>(' . implode(', ', $output) . ')</a>';
}
/**
* Implementation of hook_nodeapi_update().
*/
function search_nodeapi_update($node) {
// Reindex the node when it is updated. The node is automatically indexed
// when it is added, simply by being added to the node table.
search_touch_node($node->nid);
}
/**
* Implementation of hook_comment().
*/
function search_comment($a1, $op) {
switch ($op) {
// Reindex the node when comments are added or changed
case 'insert':
case 'update':
case 'delete':
case 'publish':
case 'unpublish':
search_touch_node(is_array($a1) ? $a1['nid'] : $a1->nid);
break;
}
}
/**
* Extract a module-specific search option from a search query. e.g. 'type:book'
*/
function search_query_extract($keys, $option) {
if (preg_match('/(^| )' . $option . ':([^ ]*)( |$)/i', $keys, $matches)) {
return $matches[2];
}
}
/**
* Return a query with the given module-specific search option inserted in.
* e.g. 'type:book'.
*/
function search_query_insert($keys, $option, $value = '') {
if (search_query_extract($keys, $option)) {
$keys = trim(preg_replace('/(^| )' . $option . ':[^ ]*/i', '', $keys));
}
if ($value != '') {
$keys .= ' ' . $option . ':' . $value;
}
return $keys;
}
/**
* Parse a search query into SQL conditions.
*
* We build two queries that matches the dataset bodies. @See do_search for
* more about these.
*
* @param $text
* The search keys.
* @return
* A list of six elements.
* * A series of statements AND'd together which will be used to provide all
* possible matches.
* * Arguments for this query part.
* * A series of exact word matches OR'd together.
* * Arguments for this query part.
* * A bool indicating whether this is a simple query or not. Negative
* terms, presence of both AND / OR make this FALSE.
* * A bool indicating the presence of a lowercase or. Maybe the user
* wanted to use OR.
*/
function search_parse_query($text) {
$keys = array('positive' => array(), 'negative' => array());
// Tokenize query string
preg_match_all('/ (-?)("[^"]+"|[^" ]+)/i', ' ' . $text, $matches, PREG_SET_ORDER);
if (count($matches) < 1) {
return NULL;
}
// Classify tokens
$or = FALSE;
$warning = '';
$simple = TRUE;
foreach ($matches as $match) {
$phrase = FALSE;
// Strip off phrase quotes
if ($match[2]{0} == '"') {
$match[2] = substr($match[2], 1, -1);
$phrase = TRUE;
$simple = FALSE;
}
// Simplify keyword according to indexing rules and external preprocessors
$words = search_simplify($match[2]);
// Re-explode in case simplification added more words, except when matching a phrase
$words = $phrase ? array($words) : preg_split('/ /', $words, -1, PREG_SPLIT_NO_EMPTY);
// Negative matches
if ($match[1] == '-') {
$keys['negative'] = array_merge($keys['negative'], $words);
}
// OR operator: instead of a single keyword, we store an array of all
// OR'd keywords.
elseif ($match[2] == 'OR' && count($keys['positive'])) {
$last = array_pop($keys['positive']);
// Starting a new OR?
if (!is_array($last)) {
$last = array($last);
}
$keys['positive'][] = $last;
$or = TRUE;
continue;
}
// AND operator: implied, so just ignore it
elseif ($match[2] == 'AND' || $match[2] == 'and') {
$warning = $match[2];
continue;
}
// Plain keyword
else {
if ($match[2] == 'or') {
$warning = $match[2];
}
if ($or) {
// Add to last element (which is an array)
$keys['positive'][count($keys['positive']) - 1] = array_merge($keys['positive'][count($keys['positive']) - 1], $words);
}
else {
$keys['positive'] = array_merge($keys['positive'], $words);
}
}
$or = FALSE;
}
// Convert keywords into SQL statements.
$query = array();
$query2 = array();
$arguments = array();
$arguments2 = array();
$matches = 0;
$simple_and = FALSE;
$simple_or = FALSE;
// Positive matches
foreach ($keys['positive'] as $key) {
// Group of ORed terms
if (is_array($key) && count($key)) {
$simple_or = TRUE;
$queryor = array();
$any = FALSE;
foreach ($key as $or) {
list($q, $num_new_scores) = _search_parse_query($or, $arguments2);
$any |= $num_new_scores;
if ($q) {
$queryor[] = $q;
$arguments[] = "% $or %";
}
}
if (count($queryor)) {
$query[] = '(' . implode(' OR ', $queryor) . ')';
// A group of OR keywords only needs to match once
$matches += ($any > 0);
}
}
// Single ANDed term
else {
$simple_and = TRUE;
list($q, $num_new_scores, $num_valid_words) = _search_parse_query($key, $arguments2);
if ($q) {
$query[] = $q;
$arguments[] = "% $key %";
if (!$num_valid_words) {
$simple = FALSE;
}
// Each AND keyword needs to match at least once
$matches += $num_new_scores;
}
}
}
if ($simple_and && $simple_or) {
$simple = FALSE;
}
// Negative matches
foreach ($keys['negative'] as $key) {
list($q) = _search_parse_query($key, $arguments2, TRUE);
if ($q) {
$query[] = $q;
$arguments[] = "% $key %";
$simple = FALSE;
}
}
$query = implode(' AND ', $query);
// Build word-index conditions for the first pass
$query2 = substr(str_repeat("i.word = '%s' OR ", count($arguments2)), 0, -4);
return array($query, $arguments, $query2, $arguments2, $matches, $simple, $warning);
}
/**
* Helper function for search_parse_query();
*/
function _search_parse_query(&$word, &$scores, $not = FALSE) {
$num_new_scores = 0;
$num_valid_words = 0;
// Determine the scorewords of this word/phrase
if (!$not) {
$split = explode(' ', $word);
foreach ($split as $s) {
$num = is_numeric($s);
if ($num || drupal_strlen($s) >= variable_get('minimum_word_size', 3)) {
$s = $num ? ((int)ltrim($s, '-0')) : $s;
if (!isset($scores[$s])) {
$scores[$s] = $s;
$num_new_scores++;
}
$num_valid_words++;
}
}
}
// Return matching snippet and number of added words
return array("d.data " . ($not ? 'NOT ' : '') . "LIKE '%s'", $num_new_scores, $num_valid_words);
}
/**
* Do a query on the full-text search index for a word or words.
*
* This function is normally only called by each module that support the
* indexed search (and thus, implements hook_update_index()).
*
* Results are retrieved in two logical passes. However, the two passes are
* joined together into a single query. And in the case of most simple
* queries the second pass is not even used.
*
* The first pass selects a set of all possible matches, which has the benefit
* of also providing the exact result set for simple "AND" or "OR" searches.
*
* The second portion of the query further refines this set by verifying
* advanced text conditions (such negative or phrase matches)
*
* @param $keywords
* A search string as entered by the user.
*
* @param $type
* A string identifying the calling module.
*
* @param $join1
* (optional) Inserted into the JOIN part of the first SQL query.
* For example "INNER JOIN {node} n ON n.nid = i.sid".
*
* @param $where1
* (optional) Inserted into the WHERE part of the first SQL query.
* For example "(n.status > %d)".
*
* @param $arguments1
* (optional) Extra SQL arguments belonging to the first query.
*
* @param $columns2
* (optional) Inserted into the SELECT pat of the second query. Must contain
* a column selected as 'calculated_score'.
* defaults to 'SUM(i.relevance) AS calculated_score'
*
* @param $join2
* (optional) Inserted into the JOIN par of the second SQL query.
* For example "INNER JOIN {node_comment_statistics} n ON n.nid = i.sid"
*
* @param $arguments2
* (optional) Extra SQL arguments belonging to the second query parameter.
*
* @param $sort_parameters
* (optional) SQL arguments for sorting the final results.
* Default: 'ORDER BY calculated_score DESC'
*
* @return
* An array of SIDs for the search results.
*
* @ingroup search
*/
function do_search($keywords, $type, $join1 = '', $where1 = '1 = 1', $arguments1 = array(), $columns2 = 'SUM(i.relevance) AS calculated_score', $join2 = '', $arguments2 = array(), $sort_parameters = 'ORDER BY calculated_score DESC') {
$query = search_parse_query($keywords);
if ($query[2] == '') {
form_set_error('keys', t('You must include at least one positive keyword with @count characters or more.', array('@count' => variable_get('minimum_word_size', 3))));
}
if ($query[6]) {
if ($query[6] == 'or') {
drupal_set_message(t('Search for either of the two terms with uppercase <strong>OR</strong>. For example, <strong>cats OR dogs</strong>.'));
}
}
if ($query === NULL || $query[0] == '' || $query[2] == '') {
return array();
}
// Build query for keyword normalization.
$conditions = "$where1 AND ($query[2]) AND i.type = '%s'";
$arguments1 = array_merge($arguments1, $query[3], array($type));
$join = "INNER JOIN {search_total} t ON i.word = t.word $join1";
if (!$query[5]) {
$conditions .= " AND ($query[0])";
$arguments1 = array_merge($arguments1, $query[1]);
$join .= " INNER JOIN {search_dataset} d ON i.sid = d.sid AND i.type = d.type";
}
// Calculate maximum keyword relevance, to normalize it.
$select = "SELECT SUM(i.score * t.count) AS calculated_score FROM {search_index} i $join WHERE $conditions GROUP BY i.type, i.sid HAVING COUNT(*) >= %d ORDER BY calculated_score DESC";
$arguments = array_merge($arguments1, array($query[4]));
$normalize = db_result(db_query_range($select, $arguments, 0, 1));
if (!$normalize) {
return array();
}
$columns2 = str_replace('i.relevance', '(' . (1.0 / $normalize) . ' * i.score * t.count)', $columns2);
// Build query to retrieve results.
$select = "SELECT i.type, i.sid, $columns2 FROM {search_index} i $join $join2 WHERE $conditions GROUP BY i.type, i.sid HAVING COUNT(*) >= %d";
$count_select = "SELECT COUNT(*) FROM ($select) n1";
$arguments = array_values(array_merge($arguments2, $arguments1, array($query[4])));
// Do actual search query
$result = pager_query("$select $sort_parameters", 10, 0, $count_select, $arguments);
$results = array();
while ($item = db_fetch_object($result)) {
$results[] = $item;
}
return $results;
}
/**
* Helper function for grabbing search keys.
*/
function search_get_keys() {
static $return;
if (!isset($return)) {
// Extract keys as remainder of path
// Note: support old GET format of searches for existing links.
$path = explode('/', $_GET['q'], 3);
$keys = empty($_REQUEST['keys']) ? '' : $_REQUEST['keys'];
$return = count($path) == 3 ? $path[2] : $keys;
}
return $return;
}
/**
* @defgroup search Search interface
* @{
* The Drupal search interface manages a global search mechanism.
*
* Modules may plug into this system to provide searches of different types of
* data. Most of the system is handled by search.module, so this must be enabled
* for all of the search features to work.
*
* There are three ways to interact with the search system:
* - Specifically for searching nodes, you can implement nodeapi('update_index')
* and nodeapi('search_result'). However, note that the search system already
* indexes all visible output of a node, i.e. everything displayed normally
* by hook_view() and hook_nodeapi('view'). This is usually sufficient.
* You should only use this mechanism if you want additional, non-visible data
* to be indexed.
* - Implement hook_search(). This will create a search tab for your module on
* the /search page with a simple keyword search form. You may optionally
* implement hook_search_item() to customize the display of your results.
* - Implement hook_update_index(). This allows your module to use Drupal's
* HTML indexing mechanism for searching full text efficiently.
*
* If your module needs to provide a more complicated search form, then you need
* to implement it yourself without hook_search(). In that case, you should
* define it as a local task (tab) under the /search page (e.g. /search/mymodule)
* so that users can easily find it.
*/
/**
* Render a search form.
*
* @param $action
* Form action. Defaults to "search".
* @param $keys
* The search string entered by the user, containing keywords for the search.
* @param $type
* The type of search to render the node for. Must be the name of module
* which implements hook_search(). Defaults to 'node'.
* @param $prompt
* A piece of text to put before the form (e.g. "Enter your keywords")
* @return
* An HTML string containing the search form.
*/
function search_form(&$form_state, $action = '', $keys = '', $type = NULL, $prompt = NULL) {
// Add CSS
drupal_add_css(drupal_get_path('module', 'search') . '/search.css', array('preprocess' => FALSE));
if (!$action) {
$action = url('search/' . $type);
}
if (is_null($prompt)) {
$prompt = t('Enter your keywords');
}
$form = array(
'#action' => $action,
'#attributes' => array('class' => 'search-form'),
);
$form['module'] = array('#type' => 'value', '#value' => $type);
$form['basic'] = array('#type' => 'item', '#title' => $prompt);
$form['basic']['inline'] = array('#prefix' => '<div class="container-inline">', '#suffix' => '</div>');
$form['basic']['inline']['keys'] = array(
'#type' => 'textfield',
'#title' => '',
'#default_value' => $keys,
'#size' => $prompt ? 40 : 20,
'#maxlength' => 255,
);
// processed_keys is used to coordinate keyword passing between other forms
// that hook into the basic search form.
$form['basic']['inline']['processed_keys'] = array('#type' => 'value', '#value' => array());
$form['basic']['inline']['submit'] = array('#type' => 'submit', '#value' => t('Search'));
return $form;
}
/**
* Form builder; Output a search form for the search block and the theme's search box.
*
* @ingroup forms
* @see search_box_form_submit()
* @see theme_search_box_form()
*/
function search_box(&$form_state, $form_id) {
$form[$form_id] = array(
'#title' => t('Search this site'),
'#type' => 'textfield',
'#size' => 15,
'#default_value' => '',
'#attributes' => array('title' => t('Enter the terms you wish to search for.')),
);
$form['submit'] = array('#type' => 'submit', '#value' => t('Search'));
$form['#submit'][] = 'search_box_form_submit';
return $form;
}
/**
* Process a block search form submission.
*/
function search_box_form_submit($form, &$form_state) {
$form_id = $form['form_id']['#value'];
$form_state['redirect'] = 'search/node/' . trim($form_state['values'][$form_id]);
}
/**
* Process variables for search-theme-form.tpl.php.
*
* The $variables array contains the following arguments:
* - $form
*
* @see search-theme-form.tpl.php
*/
function template_preprocess_search_theme_form(&$variables) {
$variables['search'] = array();
$hidden = array();
// Provide variables named after form keys so themers can print each element independently.
foreach (element_children($variables['form']) as $key) {
$type = $variables['form'][$key]['#type'];
if ($type == 'hidden' || $type == 'token') {
$hidden[] = drupal_render($variables['form'][$key]);
}
else {
$variables['search'][$key] = drupal_render($variables['form'][$key]);
}
}
// Hidden form elements have no value to themers. No need for separation.
$variables['search']['hidden'] = implode($hidden);
// Collect all form elements to make it easier to print the whole form.
$variables['search_form'] = implode($variables['search']);
}
/**
* Process variables for search-block-form.tpl.php.
*
* The $variables array contains the following arguments:
* - $form
*
* @see search-block-form.tpl.php
*/
function template_preprocess_search_block_form(&$variables) {
$variables['search'] = array();
$hidden = array();
// Provide variables named after form keys so themers can print each element independently.
foreach (element_children($variables['form']) as $key) {
$type = $variables['form'][$key]['#type'];
if ($type == 'hidden' || $type == 'token') {
$hidden[] = drupal_render($variables['form'][$key]);
}
else {
$variables['search'][$key] = drupal_render($variables['form'][$key]);
}
}
// Hidden form elements have no value to themers. No need for separation.
$variables['search']['hidden'] = implode($hidden);
// Collect all form elements to make it easier to print the whole form.
$variables['search_form'] = implode($variables['search']);
}
/**
* Perform a standard search on the given keys, and return the formatted results.
*/
function search_data($keys = NULL, $type = 'node') {
if (isset($keys)) {
if (module_hook($type, 'search')) {
$results = module_invoke($type, 'search', 'search', $keys);
if (isset($results) && is_array($results) && count($results)) {
if (module_hook($type, 'search_page')) {
return module_invoke($type, 'search_page', $results);
}
else {
return theme('search_results', $results, $type);
}
}
}
}
}
/**
* Returns snippets from a piece of text, with certain keywords highlighted.
* Used for formatting search results.
*
* @param $keys
* A string containing a search query.
*
* @param $text
* The text to extract fragments from.
*
* @return
* A string containing HTML for the excerpt.
*/
function search_excerpt($keys, $text) {
// We highlight around non-indexable or CJK characters.
$boundary = '(?:(?<=[' . PREG_CLASS_SEARCH_EXCLUDE . PREG_CLASS_CJK . '])|(?=[' . PREG_CLASS_SEARCH_EXCLUDE . PREG_CLASS_CJK . ']))';
// Extract positive keywords and phrases
preg_match_all('/ ("([^"]+)"|(?!OR)([^" ]+))/', ' ' . $keys, $matches);
$keys = array_merge($matches[2], $matches[3]);
// Prepare text
$text = ' ' . strip_tags(str_replace(array('<', '>'), array(' <', '> '), $text)) . ' ';
array_walk($keys, '_search_excerpt_replace');
$workkeys = $keys;
// Extract a fragment per keyword for at most 4 keywords.
// First we collect ranges of text around each keyword, starting/ending
// at spaces.
// If the sum of all fragments is too short, we look for second occurrences.
$ranges = array();
$included = array();
$length = 0;
while ($length < 256 && count($workkeys)) {
foreach ($workkeys as $k => $key) {
if (strlen($key) == 0) {
unset($workkeys[$k]);
unset($keys[$k]);
continue;
}
if ($length >= 256) {
break;
}
// Remember occurrence of key so we can skip over it if more occurrences
// are desired.
if (!isset($included[$key])) {
$included[$key] = 0;
}
// Locate a keyword (position $p), then locate a space in front (position
// $q) and behind it (position $s)
if (preg_match('/' . $boundary . $key . $boundary . '/iu', $text, $match, PREG_OFFSET_CAPTURE, $included[$key])) {
$p = $match[0][1];
if (($q = strpos($text, ' ', max(0, $p - 60))) !== FALSE) {
$end = substr($text, $p, 80);
if (($s = strrpos($end, ' ')) !== FALSE) {
$ranges[$q] = $p + $s;
$length += $p + $s - $q;
$included[$key] = $p + 1;
}
else {
unset($workkeys[$k]);
}
}
else {
unset($workkeys[$k]);
}
}
else {
unset($workkeys[$k]);
}
}
}
// If we didn't find anything, return the beginning.
if (count($ranges) == 0) {
return truncate_utf8($text, 256) . ' ...';
}
// Sort the text ranges by starting position.
ksort($ranges);
// Now we collapse overlapping text ranges into one. The sorting makes it O(n).
$newranges = array();
foreach ($ranges as $from2 => $to2) {
if (!isset($from1)) {
$from1 = $from2;
$to1 = $to2;
continue;
}
if ($from2 <= $to1) {
$to1 = max($to1, $to2);
}
else {
$newranges[$from1] = $to1;
$from1 = $from2;
$to1 = $to2;
}
}
$newranges[$from1] = $to1;
// Fetch text
$out = array();
foreach ($newranges as $from => $to) {
$out[] = substr($text, $from, $to - $from);
}
$text = (isset($newranges[0]) ? '' : '... ') . implode(' ... ', $out) . ' ...';
// Highlight keywords. Must be done at once to prevent conflicts ('strong' and '<strong>').
$text = preg_replace('/' . $boundary . '(' . implode('|', $keys) . ')' . $boundary . '/iu', '<strong>\0</strong>', $text);
return $text;
}
/**
* @} End of "defgroup search".
*/
/**
* Helper function for array_walk in search_except.
*/
function _search_excerpt_replace(&$text) {
$text = preg_quote($text, '/');
}
function search_forms() {
$forms['search_theme_form']= array(
'callback' => 'search_box',
'callback arguments' => array('search_theme_form'),
);
$forms['search_block_form']= array(
'callback' => 'search_box',
'callback arguments' => array('search_block_form'),
);
return $forms;
}