drupal11-ddev/web/core/modules/text/text.module

<?php

/**
 * @file
 */

use Drupal\Component\Utility\Html;
use Drupal\Component\Utility\Unicode;
use Drupal\filter\Entity\FilterFormat;

/**
 * Generates a trimmed, formatted version of a text field value.
 *
 * If the end of the summary is not indicated using the <!--break--> 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, '<!--break-->');

  // 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[] = ['</p>' => 0];

  // If no complete paragraph then treat line breaks as paragraphs.
  $line_breaks = ['<br />' => 6, '<br>' => 4];
  // Newline only indicates a line break if line break converter
  // filter is present.
  if (isset($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;
}