imageHelper.php

<?php
/**
 * Image helper with automatic image resize and cache
 *
 * @author Roman Ozana, ozana@omdesign.cz
 * @link www.omdesign.cz
 *
 * 
 * add to presenter before render function
 * 
 * $this->template->registerHelper('resize', 'ImageHelper::resize');
 * $this->template->registerHelper('resize', 'ImageHelper::gallery');
 *
 * in template
 * {= 'media/image.jpg'|resize:40}
 * {= 'media/image.jpg'|resize:?x20}
 * {= 'media/image.jpg'|resize:40:'alt'}
 * {= 'media/image.jpg'|resize:40:'alt':'title'}
 *
 * gallery link
 * {= 'media/image.jpg'|gallery}
 * 
 */
abstract class ImageHelper
{
  /**
   * Set yout folder in public WWW_DIR directory
   */
  const cache_dir = 'cache';


  /**
   * Helper for simple image tag with resize
   *
   * @param string $filename
   * @param int $width
   * @param int $height
   */
  public static function resize($filename, $dimensions = '100x?', $alt = null, $title = null)
  {
    $info = pathinfo($filename);

    $title = !is_null($alt) && is_null($title) ? $alt : $title;
    $alt = is_null($alt) ? basename($filename, '.' . $info['extension']) : $alt;

    list($src, $width, $height) = self::resizeImageWithCache($filename, $dimensions);

    return Html::el('img')->src($src)->width($width)->height($height)->alt($alt)->title($title);
  }


  /**
   * Render gallery image with anchor to bigger sized image
   * @param string $filename
   * @param string $dimensions
   * @param string $alt
   * @param string $title
   * @param string $big
   */
  public static function gallery($filename, $alt = null, $title = null, $dimensions = '120x70', $full_dimensions = '640x480')
  {
    $img = self::resize($filename, $dimensions, $alt, $title);
    list($src, $width, $height) = self::resizeImageWithCache($filename, $full_dimensions);
    return Html::el('a')->href($src)->title($title)->add($img);
  }


  /**
   * Resize image and save thumbs to cache
   * @param string $original
   * @param string $dimensions
   * @param string $subfolder
   * @param string $public_root
   * @return array
   */
  public static function resizeImageWithCache($original, $dimensions, $subfolder = 'cache', $public_root = WWW_DIR)
  {
    if (!is_file($public_root . DIRECTORY_SEPARATOR . $original))
    {
      return array ($original, null, null); // check if file exist
    }

    ////////////////////////////////////////
    // check internal cache for image
    ////////////////////////////////////////

    $cache = Environment::getCache('images');
    $key = md5($original . $dimensions . $subfolder . $public_root);

    if (isset($cache[$key]))
    {
      return $cache[$key];
    }

    $info = pathinfo($original);

    ////////////////////////////////////////
    // read dimensions
    ////////////////////////////////////////

    $dim = explode('x', $dimensions, null);
    $newWidth = isset($dim[0]) ? $dim[0] : null;
    $newHeight = isset($dim[1]) ? $dim[1] : null;

    ////////////////////////////////////////
    // check public cache directory
    ////////////////////////////////////////

    if (!is_dir($public_root . DIRECTORY_SEPARATOR . $subfolder) || !is_writable($public_root . DIRECTORY_SEPARATOR . $subfolder))
    {
      InvalidStateException('Thumbnail path ' . $subfolder . ' does not exists or is not writable.');
    }

    try
    {

      $cache_path = $subfolder . DIRECTORY_SEPARATOR . md5(dirname($original));
      if (!is_dir($public_root . DIRECTORY_SEPARATOR . $cache_path))
      {
        mkdir($public_root . DIRECTORY_SEPARATOR . $cache_path);
      }

      $image = Image::fromFile($public_root . DIRECTORY_SEPARATOR . $original);
      
      $image->resize((int) $newWidth, (int) $newHeight);
      $cache_file = String::webalize(basename($original, '.' . $info['extension']) . '-' . $image->getWidth() . 'x' . $image->getHeight()) . '.' . $info['extension'];
      $image->save($cache_path . DIRECTORY_SEPARATOR . $cache_file);

      ////////////////////////////////////////
      // resize image name
      ////////////////////////////////////////

      $resize = $subfolder . '/' . md5(dirname($original)) . '/' . $cache_file;
      $result = array ($resize, $image->getWidth(), $image->getHeight());

      ////////////////////////////////////////
      // save result to internal cache
      ////////////////////////////////////////

      $cache->save($key, $result,
              array ('files' => $public_root . DIRECTORY_SEPARATOR . $original)); // 'exire' => time() + 60 * 60)

      return $result;
    }
    catch ( Exception $e )
    {
      return array ($original, null, null);
    }
  }


}