processor_highlight.inc in Search API 7
Contains the SearchApiHighlight class.
File
includes/processor_highlight.incView source
<?php
/**
* @file
* Contains the SearchApiHighlight class.
*/
/**
* Processor for highlighting search results.
*/
class SearchApiHighlight extends SearchApiAbstractProcessor {
/**
* PREG regular expression for a word boundary.
*
* We highlight around non-indexable or CJK characters.
*
* @var string
*/
protected static $boundary;
/**
* PREG regular expression for splitting words.
*
* @var string
*/
protected static $split;
/**
* {@inheritdoc}
*/
public function __construct(SearchApiIndex $index, array $options = array()) {
parent::__construct($index, $options);
$cjk = '\\x{1100}-\\x{11FF}\\x{3040}-\\x{309F}\\x{30A1}-\\x{318E}' . '\\x{31A0}-\\x{31B7}\\x{31F0}-\\x{31FF}\\x{3400}-\\x{4DBF}\\x{4E00}-\\x{9FCF}' . '\\x{A000}-\\x{A48F}\\x{A4D0}-\\x{A4FD}\\x{A960}-\\x{A97F}\\x{AC00}-\\x{D7FF}' . '\\x{F900}-\\x{FAFF}\\x{FF21}-\\x{FF3A}\\x{FF41}-\\x{FF5A}\\x{FF66}-\\x{FFDC}' . '\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}';
self::$boundary = '(?:(?<=[' . PREG_CLASS_UNICODE_WORD_BOUNDARY . $cjk . '])|(?=[' . PREG_CLASS_UNICODE_WORD_BOUNDARY . $cjk . ']))';
self::$split = '/[' . PREG_CLASS_UNICODE_WORD_BOUNDARY . ']+/iu';
}
/**
* {@inheritdoc}
*/
public function configurationForm() {
$this->options += array(
'prefix' => '<strong>',
'suffix' => '</strong>',
'excerpt' => TRUE,
'excerpt_length' => 256,
'highlight' => 'always',
'highlight_partial' => FALSE,
'exclude_fields' => array(),
);
$form['prefix'] = array(
'#type' => 'textfield',
'#title' => t('Highlighting prefix'),
'#description' => t('Text/HTML that will be prepended to all occurrences of search keywords in highlighted text.'),
'#default_value' => $this->options['prefix'],
);
$form['suffix'] = array(
'#type' => 'textfield',
'#title' => t('Highlighting suffix'),
'#description' => t('Text/HTML that will be appended to all occurrences of search keywords in highlighted text.'),
'#default_value' => $this->options['suffix'],
);
$form['excerpt'] = array(
'#type' => 'checkbox',
'#title' => t('Create excerpt'),
'#description' => t('When enabled, an excerpt will be created for searches with keywords, containing all occurrences of keywords in a fulltext field.'),
'#default_value' => $this->options['excerpt'],
);
$form['excerpt_length'] = array(
'#type' => 'textfield',
'#title' => t('Excerpt length'),
'#description' => t('The requested length of the excerpt, in characters.'),
'#default_value' => $this->options['excerpt_length'],
'#element_validate' => array(
'element_validate_integer_positive',
),
'#states' => array(
'visible' => array(
'#edit-processors-search-api-highlighting-settings-excerpt' => array(
'checked' => TRUE,
),
),
),
);
// Exclude certain fulltext fields.
$fields = $this->index
->getFields();
$fulltext_fields = array();
foreach ($this->index
->getFulltextFields() as $field) {
if (isset($fields[$field])) {
$fulltext_fields[$field] = check_plain($fields[$field]['name'] . ' (' . $field . ')');
}
}
$form['exclude_fields'] = array(
'#type' => 'checkboxes',
'#title' => t('Exclude fields from excerpt'),
'#description' => t('Exclude certain fulltext fields from being displayed in the excerpt.'),
'#options' => $fulltext_fields,
'#default_value' => $this->options['exclude_fields'],
'#attributes' => array(
'class' => array(
'search-api-checkboxes-list',
),
),
);
$form['highlight'] = array(
'#type' => 'select',
'#title' => t('Highlight returned field data'),
'#description' => t('Select whether returned fields should be highlighted.'),
'#options' => array(
'always' => t('Always'),
'server' => t('If the server returns fields'),
'never' => t('Never'),
),
'#default_value' => $this->options['highlight'],
);
$form['highlight_partial'] = array(
'#type' => 'checkbox',
'#title' => t('Highlight partial matches'),
'#description' => t('When enabled, matches in parts of words will be highlighted as well.'),
'#default_value' => $this->options['highlight_partial'],
);
return $form;
}
/**
* {@inheritdoc}
*/
public function configurationFormValidate(array $form, array &$values, array &$form_state) {
$values['exclude_fields'] = array_filter($values['exclude_fields']);
}
/**
* {@inheritdoc}
*/
public function postprocessSearchResults(array &$response, SearchApiQuery $query) {
if (empty($response['results']) || !($keys = $this
->getKeywords($query))) {
return;
}
$fulltext_fields = $this->index
->getFulltextFields();
if (!empty($this->options['exclude_fields'])) {
$fulltext_fields = drupal_map_assoc($fulltext_fields);
foreach ($this->options['exclude_fields'] as $field) {
unset($fulltext_fields[$field]);
}
}
foreach ($response['results'] as $id => &$result) {
if ($this->options['excerpt']) {
$text = array();
$fields = $this
->getFulltextFields($response['results'], $id, $fulltext_fields);
foreach ($fields as $data) {
if (is_array($data)) {
$text = array_merge($text, $data);
}
else {
$text[] = $data;
}
}
$result['excerpt'] = $this
->createExcerpt($this
->flattenArrayValues($text), $keys);
}
if ($this->options['highlight'] != 'never') {
$fields = $this
->getFulltextFields($response['results'], $id, $fulltext_fields, $this->options['highlight'] == 'always');
foreach ($fields as $field => $data) {
$result['fields'][$field] = array(
'#sanitize_callback' => FALSE,
);
if (is_array($data)) {
foreach ($data as $i => $text) {
$result['fields'][$field]['#value'][$i] = $this
->highlightField($text, $keys);
}
}
else {
$result['fields'][$field]['#value'] = $this
->highlightField($data, $keys);
}
}
}
}
}
/**
* Retrieves the fulltext data of a result.
*
* @param array $results
* All results returned in the search, by reference.
* @param int|string $i
* The index in the results array of the result whose data should be
* returned.
* @param array $fulltext_fields
* The fulltext fields from which the excerpt should be created.
* @param bool $load
* TRUE if the item should be loaded if necessary, FALSE if only fields
* already returned in the results should be used.
*
* @return array
* An array containing fulltext field names mapped to the text data
* contained in them for the given result.
*/
protected function getFulltextFields(array &$results, $i, array $fulltext_fields, $load = TRUE) {
global $language;
$data = array();
$result =& $results[$i];
// Act as if $load is TRUE if we have a loaded item.
$load |= !empty($result['entity']);
$result += array(
'fields' => array(),
);
// We only need detailed fields data if $load is TRUE.
$fields = $load ? $this->index
->getFields() : array();
$needs_extraction = array();
$returned_fields = search_api_get_sanitized_field_values(array_intersect_key($result['fields'], array_flip($fulltext_fields)));
foreach ($fulltext_fields as $field) {
if (array_key_exists($field, $returned_fields)) {
$data[$field] = $returned_fields[$field];
}
elseif ($load) {
$needs_extraction[$field] = $fields[$field];
}
}
if (!$needs_extraction) {
return $data;
}
if (empty($result['entity'])) {
$items = $this->index
->loadItems(array_keys($results));
foreach ($items as $id => $item) {
$results[$id]['entity'] = $item;
}
}
// If we still don't have a loaded item, we should stop trying.
if (empty($result['entity'])) {
return $data;
}
$wrapper = $this->index
->entityWrapper($result['entity'], FALSE);
$wrapper
->language($language->language);
$extracted = search_api_extract_fields($wrapper, $needs_extraction, array(
'sanitize' => TRUE,
));
foreach ($extracted as $field => $info) {
if (isset($info['value'])) {
$data[$field] = $info['value'];
}
}
return $data;
}
/**
* Extracts the positive keywords used in a search query.
*
* @param SearchApiQuery $query
* The query from which to extract the keywords.
*
* @return array
* An array of all unique positive keywords used in the query.
*/
protected function getKeywords(SearchApiQuery $query) {
$keys = $query
->getKeys();
if (!$keys) {
return array();
}
if (is_array($keys)) {
return $this
->flattenKeysArray($keys);
}
$keywords = preg_split(self::$split, $keys);
// Assure there are no duplicates. (This is actually faster than
// array_unique() by a factor of 3 to 4.)
$keywords = drupal_map_assoc(array_filter($keywords));
// Remove quotes from keywords.
foreach ($keywords as $key) {
$keywords[$key] = trim($key, "'\" ");
}
return drupal_map_assoc(array_filter($keywords));
}
/**
* Extracts the positive keywords from a keys array.
*
* @param array $keys
* A search keys array, as specified by SearchApiQueryInterface::getKeys().
*
* @return array
* An array of all unique positive keywords contained in the keys.
*/
protected function flattenKeysArray(array $keys) {
if (!empty($keys['#negation'])) {
return array();
}
$keywords = array();
foreach ($keys as $i => $key) {
if (!element_child($i)) {
continue;
}
if (is_array($key)) {
$keywords += $this
->flattenKeysArray($key);
}
else {
$keywords[$key] = trim($key);
}
}
return $keywords;
}
/**
* Returns snippets from a piece of text, with certain keywords highlighted.
*
* Largely copied from search_excerpt().
*
* @param string $text
* The text to extract fragments from.
* @param array $keys
* Search keywords entered by the user.
*
* @return string|null
* A string containing HTML for the excerpt, or NULL if none could be
* created.
*/
protected function createExcerpt($text, array $keys) {
// Prepare text by stripping HTML tags and decoding HTML entities.
$text = strip_tags(str_replace(array(
'<',
'>',
), array(
' <',
'> ',
), $text));
$text = decode_entities($text);
$text = preg_replace('/\\s+/', ' ', $text);
$text = trim($text, ' ');
$text_length = strlen($text);
// Try to reach the requested excerpt length with about two fragments (each
// with a keyword and some context).
$ranges = array();
$length = 0;
$look_start = array();
$remaining_keys = $keys;
// Get the set excerpt length from the configuration. If the length is too
// small, only use one fragment.
$excerpt_length = $this->options['excerpt_length'];
$context_length = round($excerpt_length / 4) - 3;
if ($context_length < 32) {
$context_length = round($excerpt_length / 2) - 1;
}
while ($length < $excerpt_length && !empty($remaining_keys)) {
$found_keys = array();
foreach ($remaining_keys as $key) {
if ($length >= $excerpt_length) {
break;
}
// Remember where we last found $key, in case we are coming through a
// second time.
if (!isset($look_start[$key])) {
$look_start[$key] = 0;
}
// See if we can find $key after where we found it the last time. Since
// we are requiring a match on a word boundary, make sure $text starts
// and ends with a space.
$matches = array();
if (empty($this->options['highlight_partial'])) {
$found_position = FALSE;
$regex = '/' . static::$boundary . preg_quote($key, '/') . static::$boundary . '/iu';
if (preg_match($regex, ' ' . $text . ' ', $matches, PREG_OFFSET_CAPTURE, $look_start[$key])) {
$found_position = $matches[0][1];
}
}
else {
$found_position = stripos($text, $key, $look_start[$key]);
}
if ($found_position !== FALSE) {
$look_start[$key] = $found_position + 1;
// Keep track of which keys we found this time, in case we need to
// pass through again to find more text.
$found_keys[] = $key;
// Locate a space before and after this match, leaving some context on
// each end.
if ($found_position > $context_length) {
$before = strpos($text, ' ', $found_position - $context_length);
if ($before !== FALSE) {
++$before;
}
}
else {
$before = 0;
}
if ($before !== FALSE && $before <= $found_position) {
if ($text_length > $found_position + $context_length) {
$after = strrpos(substr($text, 0, $found_position + $context_length), ' ', $found_position);
}
else {
$after = $text_length;
}
if ($after !== FALSE && $after > $found_position) {
if ($before < $after) {
// Save this range.
$ranges[$before] = $after;
$length += $after - $before;
}
}
}
}
}
// Next time through this loop, only look for keys we found this time,
// if any.
$remaining_keys = $found_keys;
}
if (!$ranges) {
// We didn't find any keyword matches, return NULL.
return NULL;
}
// Sort the text ranges by starting position.
ksort($ranges);
// Collapse overlapping text ranges into one. The sorting makes it O(n).
$newranges = array();
$from1 = $to1 = NULL;
foreach ($ranges as $from2 => $to2) {
if ($from1 === NULL) {
// This is the first time through this loop: initialize.
$from1 = $from2;
$to1 = $to2;
continue;
}
if ($from2 <= $to1) {
// The ranges overlap: combine them.
$to1 = max($to1, $to2);
}
else {
// The ranges do not overlap: save the working range and start a new
// one.
$newranges[$from1] = $to1;
$from1 = $from2;
$to1 = $to2;
}
}
// Save the remaining working range.
$newranges[$from1] = $to1;
// Fetch text within the combined ranges we found.
$out = array();
foreach ($newranges as $from => $to) {
$out[] = substr($text, $from, $to - $from);
}
if (!$out) {
return NULL;
}
// Let translators have the ... separator text as one chunk.
$dots = explode('!excerpt', t('... !excerpt ... !excerpt ...'));
$text = (isset($newranges[0]) ? '' : $dots[0]) . implode($dots[1], $out) . $dots[2];
$text = check_plain($text);
// Since we stripped the tags at the beginning, highlighting doesn't need to
// handle HTML anymore.
return $this
->highlightField($text, $keys, FALSE);
}
/**
* Marks occurrences of the search keywords in a text field.
*
* @param string $text
* The text of the field.
* @param array $keys
* Search keywords entered by the user.
* @param bool $html
* Whether the text can contain HTML tags or not. In the former case, text
* inside tags (i.e., tag names and attributes) won't be highlighted.
*
* @return string
* The field's text with all occurrences of search keywords highlighted.
*/
protected function highlightField($text, array $keys, $html = TRUE) {
if (is_array($text)) {
$text = $this
->flattenArrayValues($text);
}
if ($html) {
$texts = preg_split('#((?:</?[[:alpha:]](?:[^>"\']*|"[^"]*"|\'[^\']\')*>)+)#i', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
for ($i = 0; $i < count($texts); $i += 2) {
$texts[$i] = $this
->highlightField($texts[$i], $keys, FALSE);
}
return implode('', $texts);
}
$keys = implode('|', array_map('preg_quote', $keys, array_fill(0, count($keys), '/')));
// If "Highlight partial matches" is disabled, we only want to highlight
// matches that are complete words. Otherwise, we want all of them.
$boundary = empty($this->options['highlight_partial']) ? self::$boundary : '';
$regex = '/' . $boundary . '(?:' . $keys . ')' . $boundary . '/iu';
$replace = $this->options['prefix'] . '\\0' . $this->options['suffix'];
$text = preg_replace($regex, $replace, ' ' . $text . ' ');
return substr($text, 1, -1);
}
/**
* Flattens a (possibly multidimensional) array into a string.
*
* @param array $array
* The array to flatten.
* @param string $glue
* (optional) The separator to insert between individual array items.
*
* @return string
* The glued string.
*/
protected function flattenArrayValues(array $array, $glue = " \n\n ") {
$ret = array();
foreach ($array as $item) {
if (is_array($item)) {
$ret[] = $this
->flattenArrayValues($item, $glue);
}
else {
$ret[] = $item;
}
}
return implode($glue, $ret);
}
}Classes
Name |
Description |
|---|---|
| SearchApiHighlight | Processor for highlighting search results. |