delimiter
* then we generate the summary automatically, trying to end it at a sensible
* place such as the end of a paragraph, a line break, or the end of a sentence
* (in that order of preference).
*
* @param string $text
* The content for which a summary will be generated.
* @param string $format
* The format of the content. If the line break filter is present then we
* treat newlines embedded in $text as line breaks. If the htmlcorrector
* filter is present, it will be run on the generated summary (if different
* from the incoming $text).
* @param string|null $size
* The desired character length of the summary. If omitted, the default value
* will be used. Ignored if the special delimiter is present in $text.
*
* @return string
* The generated summary.
*/
function text_summary($text, $format = NULL, $size = NULL) {
if (!isset($size)) {
$size = \Drupal::config('text.settings')->get('default_summary_length');
}
// Find where the delimiter is in the body.
$delimiter = strpos($text, '');
// If the size is zero, and there is no delimiter, the entire body is the
// summary.
if ($size == 0 && $delimiter === FALSE) {
return $text;
}
// If a valid delimiter has been specified, use it to chop off the summary.
if ($delimiter !== FALSE) {
return substr($text, 0, $delimiter);
}
// Retrieve the filters of the specified text format, if any.
if (isset($format)) {
$filter_format = FilterFormat::load($format);
// If the specified format does not exist, return nothing. $text is already
// filtered text, but the remainder of this function will not be able to
// ensure a sane and secure summary.
if (!$filter_format || !($filters = $filter_format->filters())) {
return '';
}
}
// If we have a short body, the entire body is the summary.
if (mb_strlen($text) <= $size) {
return $text;
}
// If the delimiter has not been specified, try to split at paragraph or
// sentence boundaries.
// The summary may not be longer than maximum length specified. Initial slice.
$summary = Unicode::truncate($text, $size);
// Store the actual length of the UTF8 string -- which might not be the same
// as $size.
$max_right_pos = strlen($summary);
// How much to cut off the end of the summary so that it doesn't end in the
// middle of a paragraph, sentence, or word.
// Initialize it to maximum in order to find the minimum.
$min_right_pos = $max_right_pos;
// Store the reverse of the summary. We use strpos on the reversed needle and
// haystack for speed and convenience.
$reversed = strrev($summary);
// Build an array of arrays of break points grouped by preference.
$break_points = [];
// A paragraph near the end of sliced summary is most preferable.
$break_points[] = ['' => 0];
// If no complete paragraph then treat line breaks as paragraphs.
$line_breaks = ['
' => 6, '
' => 4];
// Newline only indicates a line break if line break converter
// filter is present.
if (isset($format) && $filters->has('filter_autop') && $filters->get('filter_autop')->status) {
$line_breaks["\n"] = 1;
}
$break_points[] = $line_breaks;
// If the first paragraph is too long, split at the end of a sentence.
$break_points[] = ['. ' => 1, '! ' => 1, '? ' => 1, '。' => 0, '؟ ' => 1];
// Iterate over the groups of break points until a break point is found.
foreach ($break_points as $points) {
// Look for each break point, starting at the end of the summary.
foreach ($points as $point => $offset) {
// The summary is already reversed, but the break point isn't.
$right_pos = strpos($reversed, strrev($point));
if ($right_pos !== FALSE) {
$min_right_pos = min($right_pos + $offset, $min_right_pos);
}
}
// If a break point was found in this group, slice and stop searching.
if ($min_right_pos !== $max_right_pos) {
// Don't slice with length 0. Length must be <0 to slice from RHS.
$summary = ($min_right_pos === 0) ? $summary : substr($summary, 0, 0 - $min_right_pos);
break;
}
}
// If filter_html or filter_htmlcorrector is enabled, normalize the output.
if (isset($format)) {
$filter_enabled = function (string $filter) use ($filters) : bool {
return $filters->has($filter) && $filters->get($filter)->status;
};
if ($filter_enabled('filter_html') || $filter_enabled('filter_htmlcorrector')) {
$summary = Html::normalize($summary);
}
}
return $summary;
}