class.lessautoprefixer.inc in Less CSS Preprocessor 7.4

Contains 'LessAutoprefixer' class; an abstraction layer for command line Autoprefixer.

File

classes/class.lessautoprefixer.inc

<?php

/**
 * @file
 * Contains 'LessAutoprefixer' class; an abstraction layer for command line Autoprefixer.
 */

/**
 * 'Autoprefixer' class.
 */
class LessAutoprefixer {

  // Base command is hardcoded here to reduce security vulnerability.
  const BASE_COMMAND = 'autoprefixer';
  protected $input_file = NULL;
  protected $source_maps_enabled = FALSE;

  /**
   * Constructor function for 'LessAutoprefixer'.
   *
   * @param string $input_file
   *   Path for .less file relative to getcwd().
   */
  protected function __construct($input_file) {
    $this->input_file = $input_file;
  }

  /**
   * @param string $input_file
   *
   * @return LessAutoprefixer
   */
  public static function create($input_file) {
    return new self($input_file);
  }

  /**
   * Returns the version string from command line Autoprefixer.
   *
   * @return string|null
   *   Version string from Autoprefixer, or null if no version found.
   */
  public static function version() {
    $version = NULL;
    if (function_exists('proc_open')) {
      try {
        $version_response = self::create(NULL)
          ->proc_open(array(
          '--version',
        ));
        $version = preg_replace('/.*?([\\d\\.]+).*/', '$1', $version_response);
      } catch (Exception $e) {
      }
    }
    return $version;
  }

  /**
   * Enable source maps for current file, and configure source map paths.
   *
   * @param bool $enabled
   *   Set the source maps flag.
   */
  public function source_maps($enabled) {
    $this->source_maps_enabled = $enabled;
  }

  /**
   * Provides list to command line arguments for execution.
   *
   * @return array
   *   Array of command line arguments.
   */
  protected function command_arguments() {
    $arguments = array();

    // Set service map flags.
    if ($this->source_maps_enabled) {
      $arguments[] = '--map';
      $arguments[] = '--inline-map';
    }

    // Input file should be last argument.
    $arguments[] = $this->input_file;
    return $arguments;
  }

  /**
   * Executes auto-prefixing of LESS output file.
   *
   * @return string
   *   Compiled CSS.
   */
  public function compile() {
    return $this
      ->proc_open($this
      ->command_arguments());
  }
  protected function proc_open($command_arguments = array()) {
    $output_data = NULL;
    $command = implode(' ', array_merge(array(
      self::BASE_COMMAND,
    ), $command_arguments));

    // Handles for data exchange.
    $pipes = array(
      0 => NULL,
      // STDIN
      1 => NULL,
      // STDOUT
      2 => NULL,
    );

    // Sets permissions on $pipes.
    $descriptors = array(
      0 => array(
        'pipe',
        'r',
      ),
      // STDIN
      1 => array(
        'pipe',
        'w',
      ),
      // STDOUT
      2 => array(
        'pipe',
        'w',
      ),
    );
    try {
      $process = proc_open($command, $descriptors, $pipes);
      if (is_resource($process)) {
        fclose($pipes[0]);

        // fclose() on STDIN executes $command, if program is expecting input from STDIN.
        $output_data = stream_get_contents($pipes[1]);
        fclose($pipes[1]);
        $error = stream_get_contents($pipes[2]);
        fclose($pipes[2]);
        if (!empty($error)) {
          throw new Exception($error);
        }
        proc_close($process);
      }
    } catch (Exception $e) {
      throw $e;
    }
    return $output_data;
  }

}

Classes

Name	Description
LessAutoprefixer	'Autoprefixer' class.