class Diff

backdrop_class_list in core/includes/bootstrap.classes.inc

Lists all the classes used by Backdrop core.

config_diff_page in core/modules/config/config.admin.inc

Shows diff of specified configuration file.

file_default_mimetype_mapping in core/includes/file.mimetypes.inc

Default MIME extension mapping.

class Diff {
  public $edits;

  /**
   * Constructor.
   * Computes diff between sequences of strings.
   *
   * @param $from_lines array An array of strings.
   *   Typically these are lines from a file.
   * @param $to_lines array An array of strings.
   */
  function __construct($from_lines, $to_lines) {
    $eng = new DiffEngine;
    $this->edits = $eng->diff($from_lines, $to_lines);
  }

  /**
   * Compute reversed Diff.
   *
   * SYNOPSIS:
   *
   *    $diff = new Diff($lines1, $lines2);
   *    $rev = $diff->reverse();
   * @return Object A Diff object representing the inverse of the
   *   original diff.
   */
  function reverse() {
    $rev = $this;
    $rev->edits = array();
    /** @var DiffOp $edit */
    foreach ($this->edits as $edit) {
      $rev->edits[] = $edit->reverse();
    }

    return $rev;
  }

  /**
   * Check for empty diff.
   *
   * @return bool True if two sequences were identical.
   */
  function isEmpty() {
    foreach ($this->edits as $edit) {
      if ($edit->type != 'copy') {
        return FALSE;
      }
    }

    return TRUE;
  }

  /**
   * Compute the length of the Longest Common Subsequence (LCS).
   *
   * This is mostly for diagnostic purposed.
   *
   * @return int The length of the LCS.
   */
  function lcs() {
    $lcs = 0;
    foreach ($this->edits as $edit) {
      if ($edit->type == 'copy') {
        $lcs += count($edit->orig);
      }
    }

    return $lcs;
  }

  /**
   * Get the original set of lines.
   *
   * This reconstructs the $from_lines parameter passed to the
   * constructor.
   *
   * @return array The original sequence of strings.
   */
  function orig() {
    $lines = array();

    foreach ($this->edits as $edit) {
      if ($edit->orig) {
        array_splice($lines, count($lines), 0, $edit->orig);
      }
    }

    return $lines;
  }

  /**
   * Get the closing set of lines.
   *
   * This reconstructs the $to_lines parameter passed to the
   * constructor.
   *
   * @return array The sequence of strings.
   */
  function closing() {
    $lines = array();

    foreach ($this->edits as $edit) {
      if ($edit->closing) {
        array_splice($lines, count($lines), 0, $edit->closing);
      }
    }

    return $lines;
  }
}