maintenance-1.0.0-beta1/src/MaintenanceStringHelperTrait.php

<?php

namespace Drupal\maintenance;

/**
 * Provides helper methods for converting strings to arrays and vice versa.
 *
 * Used to process multi-line text input fields (e.g., IPs, paths) into
 * structured arrays and format them back into storage-friendly strings.
 */
trait MaintenanceStringHelperTrait {

  /**
   * Converts a string with newline characters into an array of trimmed lines.
   *
   * Converts user input from multiline text fields (e.g., IPs or paths)
   * into an array by normalizing line endings, trimming each line,
   * and removing any blank entries to ensure clean structured data.
   *
   * @param string $text
   *   Input text with line breaks (\n or \r\n).
   *
   * @return array|null
   *   Array of non-empty trimmed lines, or NULL if input is invalid.
   */
  protected function stringToArray($text): array|null {
    // Validate input: must be a string.
    if (!is_string($text)) {
      return NULL;
    }

    // Normalize Windows line endings to Unix style.
    $text = str_replace("\r\n", "\n", $text);

    // Explode the text by newline and remove empty lines.
    return array_filter(
      array_map('trim', explode("\n", $text)),
      static fn($line) => $line !== ''
    );
  }

  /**
   * Converts an array of lines into a single string separated by line breaks.
   *
   * Formats a list of string values for use in multiline form fields by
   * filtering out invalid or empty lines and combining entries with consistent
   * Windows-style line breaks to maintain configuration integrity.
   *
   * @param array $array
   *   An array of strings to be joined.
   *
   * @return string|null
   *   A string with each value on its own line, or NULL if input is invalid.
   */
  protected function arrayToString($array): string|null {
    // Ensure input is a valid array.
    if (!is_array($array)) {
      return NULL;
    }

    // Filter out empty or non-string values.
    $array = array_filter($array, static fn($item) => is_string($item) && trim($item) !== '');

    // Join array elements using Windows-style line breaks for consistency.
    return implode("\r\n", $array);
  }

}