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pdfpreview.module in PDFPreview 6

Same filename and directory in other branches
  1. 8 pdfpreview.module
  2. 7.2 pdfpreview.module
  3. 7 pdfpreview.module
  4. 2.0.x pdfpreview.module

This module creates a formatter for CCK filefields that shows a snapshot of the first page of pdf files as link to the file.

pdfpreview PDFPreview: generate snapshots of PDF files to use as link to them. @author Juanjo Garcia <juanjo.gcia@gmail.com> Main file for the pdfpreview module

File

pdfpreview.module
View source 
<?php

/**
 * @file
 * This module creates a formatter for CCK filefields that
 * shows a snapshot of the first page of pdf files as link
 * to the file.
 *
 * @defgroup pdfpreview PDFPreview: generate snapshots of PDF files to use as link to them.
 * @author Juanjo Garcia <juanjo.gcia@gmail.com>
 *  Main file for the pdfpreview module
 *
 */
define('PDFPREVIEW_DEFAULT_QUALITY', 75);
define('PDFPREVIEW_DEFAULT_SIZE', '1024x1024');
define('PDFPREVIEW_DEFAULT_SHOW_DESCRIPTION', 0);
define('PDFPREVIEW_DEFAULT_TAG', 'span');
define('PDFPREVIEW_FILENAMES_MACHINE', 0);
define('PDFPREVIEW_FILENAMES_HUMAN', 1);

/**
 * Implements hook_field_formatter_info().
 */
function pdfpreview_field_formatter_info() {
  $formatters = array(
    'default' => array(
      'label' => t('PDF Preview'),
      'field types' => array(
        'filefield',
      ),
      'description' => t('Displays an snapshot of the first page of the PDF'),
    ),
  );
  if (module_exists('imagecache')) {
    foreach (imagecache_presets() as $preset) {
      $formatters[$preset['presetname'] . '][pdfpreview'] = array(
        'label' => t('PDF Preview: @preset image', array(
          '@preset' => $preset['presetname'],
        )),
        'field types' => array(
          'filefield',
        ),
        'description' => t('Display an snapshot using imagecache preset @preset', array(
          '@preset' => $preset['presetname'],
        )),
      );
    }
  }
  return $formatters;
}

/**
 * Implements hook_theme().
 *
 * We declare our theme functions according to the array keys in  hook_field_formatter_info
 */
function pdfpreview_theme() {
  $theme = array(
    'pdfpreview_formatter_default' => array(
      'function' => 'theme_pdfpreview_formatter',
      'arguments' => array(
        'element' => NULL,
      ),
    ),
  );
  if (module_exists('imagecache')) {
    foreach (imagecache_presets() as $preset) {
      $theme['pdfpreview_formatter_' . $preset['presetname'] . '][pdfpreview'] = array(
        'function' => 'theme_pdfpreview_formatter',
        'arguments' => array(
          'element' => NULL,
        ),
      );
    }
  }
  return $theme;
}

/**
 * Theming functions for our formatters
 */
function theme_pdfpreview_formatter($element) {
  $output = '';
  $item = $element['#item'];
  if ($item['filemime'] != 'application/pdf' or $item['list'] != 1) {
    return '';
  }
  $output_filename = _pdfpreview_create_preview($item);
  $output = "<img src=\"/{$output_filename}\" title=\"{$item['data']['description']}\" alt=\"{$item['data']['description']}\" />";
  if (list($namespace, $presetname) = explode('][', $element['#formatter'], 2)) {
    if ($preset = imagecache_preset_by_name($namespace)) {
      $output = theme('imagecache', $namespace, $output_filename, $item['data']['alt'], $item['data']['title']);
    }
  }
  $tag = variable_get('pdfpreview_tag', 'span');
  $description = variable_get('pdfpreview_description', 1) ? "<{$tag} class=\"pdfpreview-description\">{$item['data']['description']}</{$tag}>" : '';
  return "<div class=\"pdfpreview\" id=\"pdfpreview-{$item['fid']}\">\n    <{$tag} class=\"image-wrapper\"><a href=\"/{$item['filepath']}\" title=\"{$item['data']['description']}\">\n    {$output}</a></{$tag}>{$description}</div>";
}

/**
 * Implements hook_menu()
 */
function pdfpreview_menu() {
  $items = array(
    'admin/settings/pdfpreview' => array(
      'title' => 'Configure PDF Preview',
      'description' => 'Configure PDF Preview settings',
      'access arguments' => array(
        'administer content',
      ),
      'page callback' => 'drupal_get_form',
      'page arguments' => array(
        'pdfpreview_admin_settings',
      ),
      'type' => MENU_NORMAL_ITEM,
    ),
  );
  return $items;
}

/**
 * Creates the settings form to tune how pdfpreview works.
 * @return themed settings form
 */
function pdfpreview_admin_settings() {
  $form = array(
    'pdfpreview_pathtoimages' => array(
      '#type' => 'textfield',
      '#title' => t('Images folder'),
      '#description' => t('Path, inside files directory, where snapshots are stored. For example <em>pdfpreview</em>'),
      '#default_value' => variable_get('pdfpreview_pathtoimages', 'pdfpreview'),
    ),
    'pdfpreview_previewsize' => array(
      '#type' => 'textfield',
      '#title' => t('Preview size'),
      '#description' => t('Size of the preview in pixels. For example <em>100x100</em>. You must set this to a value big enought to apply your image styles.'),
      '#default_value' => variable_get('pdfpreview_previewsize', PDFPREVIEW_DEFAULT_SIZE),
    ),
    'pdfpreview_quality' => array(
      '#type' => 'textfield',
      '#size' => 3,
      '#maxlenght' => 3,
      '#title' => t('Image quality'),
      '#field_suffix' => '%',
      '#description' => t('Image extraction quality in percentage.'),
      '#default_value' => variable_get('pdfpreview_quality', PDFPREVIEW_DEFAULT_QUALITY),
    ),
    'pdfpreview_description' => array(
      '#type' => 'checkbox',
      '#title' => t('Description'),
      '#description' => t('Show file description beside image'),
      '#options' => array(
        0 => t('No'),
        1 => t('Yes'),
      ),
      '#default_value' => variable_get('pdfpreview_description', PDFPREVIEW_DEFAULT_SHOW_DESCRIPTION),
    ),
    'pdfpreview_tag' => array(
      '#type' => 'radios',
      '#title' => t('HTML tag'),
      '#description' => t('Select which kind of HTML element will be used to theme elements'),
      '#options' => array(
        'span' => 'span',
        'div' => 'div',
      ),
      '#default_value' => variable_get('pdfpreview_tag', PDFPREVIEW_DEFAULT_TAG),
    ),
    'pdfpreview_filenames' => array(
      '#type' => 'radios',
      '#options' => array(
        PDFPREVIEW_FILENAMES_MACHINE => t('Filename hash'),
        PDFPREVIEW_FILENAMES_HUMAN => t('From pdf filename'),
      ),
      '#default_value' => variable_get('pdfpreview_filenames', PDFPREVIEW_FILENAMES_MACHINE),
      '#title' => t('Generated filenames'),
      '#description' => t('This changes how filenames will be used on genereated previews. If you change this after some files were generated, you must delete them manually.'),
    ),
  );
  return system_settings_form($form);
}
function _pdfpreview_output_filename($file) {
  if (!is_object($file)) {
    $file = (object) $file;
  }
  $output_dir = file_directory_path() . '/' . variable_get('pdfpreview_pathtoimages', 'pdfpreview');
  if (variable_get('pdfpreview_filenames', PDFPREVIEW_FILENAMES_MACHINE) == PDFPREVIEW_FILENAMES_HUMAN) {
    $filename = basename($file->filename, '.pdf');
    if (module_exists('transliteration')) {
      $filename = transliteration_clean_filename($filename);
    }
    return $output_dir . '/' . $file->fid . '-' . $filename . '.jpg';
  }
  else {
    return $output_dir . '/' . md5($file->fid) . '.jpg';
  }
}

/**
 * Implements hook_file_delete()
 */
function pdfpreview_file_delete($file) {
  file_delete(_pdfpreview_output_filename($file));
}

/**
 * Implements hook_form_FORM_ID_validate()
 */
function pdfpreview_admin_settings_validate(&$form, &$form_state) {
  if (!_pdfpreview_prepare_filesystem(file_directory_path() . '/' . $form_state['values']['pdfpreview_pathtoimages'])) {
    form_set_error('pdfpreview_pathtoimages', t('Invalid path @path', array(
      '@path' => $form_state['values']['pdfpreview_pathtoimages'],
    )));
  }
}

/**
 * Prepares filesystem to store previews
 */
function _pdfpreview_prepare_filesystem($output_dir) {
  $output_dir = _pdfpreview_realpath($output_dir);
  if (!file_exists($output_dir)) {
    if (!mkdir($output_dir)) {
      drupal_set_message(t('Error creating directory %dir', array(
        '%dir' => $output_dir,
      )), 'error');
      watchdog('pdfpreview', 'Error creating directory %dir', array(
        '%dir' => $output_dir,
      ), WATCHDOG_ERROR);
      return FALSE;
    }
    $message = t('The directory %dir has been created', array(
      '%dir' => $output_dir,
    ));
    watchdog('pdfpreview', 'The directory %dir has been created', array(
      '%dir' => $output_dir,
    ));
    drupal_set_message($message, 'status');
    return TRUE;
  }
  elseif (!is_dir($output_dir)) {
    $message = t('The path %dir is not a directory', array(
      '%dir' => $output_dir,
    ));
    watchdog('pdfpreview', 'The path %dir is not a directory', array(
      '%dir' => $output_dir,
    ), WATCHDOG_ERROR);
    drupal_set_message($message, 'error');
    return FALSE;
  }
  return TRUE;
}

/**
 * Convert the first page of a PDF document
 *
 * This function converts the first page of a PDF document using ImageMagick's
 * convert executable and returns TRUE on success, FALSE else. You can provide
 * optional parameters for the convert executable by simply passing them with
 * in an array to the $args parameter. For details about convert arguments see
 * the <a href="http://www.imagemagick.org/Usage/basics/#cmdline">ImageMagick
 * documentation</a>.
 *
 * @param $source URI to the PDF file
 * @param $dest URI where the preview file will be saved
 * @param $args Optional arguments for the convert executable
 * @see _imagemagick_convert()
 * @see _pdfpreview_create_preview()
 */
function _pdfpreview_convert_first_page($source, $dest, $args = array()) {
  $source = _pdfpreview_realpath($source) . '[0]';
  $dest = _pdfpreview_realpath($dest);
  $args['quality'] = '-quality ' . escapeshellarg(variable_get('imagemagick_quality', PDFPREVIEW_DEFAULT_QUALITY));
  $args['previewsize'] = '-resize ' . escapeshellarg(variable_get('pdfpreview_previewsize', PDFPREVIEW_DEFAULT_SIZE));
  $context = array(
    'source' => $source,
    'destination' => $dest,
  );
  drupal_alter('imagemagick_arguments', $args, $context);

  // To make use of ImageMagick 6's parenthetical command grouping we need to make
  // the $source image the first parameter and $dest the last.
  // See http://www.imagemagick.org/Usage/basics/#cmdline
  $command = escapeshellarg($source) . ' ' . implode(' ', $args) . ' ' . escapeshellarg($dest);
  if (_imageapi_imagemagick_convert_exec($command, $output, $error) !== TRUE) {
    return FALSE;
  }
  return file_exists($dest);
}

/**
 * Creates the PDF preview file and returns its URI
 *
 * @param File $file
 * @return string URI of the newly created preview image
 * @see _pdfpreview_convert_first_page()
 * @see pdfpreview_field_formatter_view()
 */
function _pdfpreview_create_preview($file) {
  if (!is_array($file)) {
    $file = (array) $file;
  }
  $output_filename = _pdfpreview_output_filename($file);

  // Create preview image using ImageMagick
  if (!file_exists($output_filename) && function_exists('_imageapi_imagemagick_convert_exec')) {
    _pdfpreview_convert_first_page($file['filepath'], $output_filename);
  }
  return $output_filename;
}
function _pdfpreview_realpath($path) {
  return $_SERVER['DOCUMENT_ROOT'] . base_path() . $path;
}

Functions

Namesort descending Description
pdfpreview_admin_settings Creates the settings form to tune how pdfpreview works.
pdfpreview_admin_settings_validate Implements hook_form_FORM_ID_validate()
pdfpreview_field_formatter_info Implements hook_field_formatter_info().
pdfpreview_file_delete Implements hook_file_delete()
pdfpreview_menu Implements hook_menu()
pdfpreview_theme Implements hook_theme().
theme_pdfpreview_formatter Theming functions for our formatters
_pdfpreview_convert_first_page Convert the first page of a PDF document
_pdfpreview_create_preview Creates the PDF preview file and returns its URI
_pdfpreview_output_filename
_pdfpreview_prepare_filesystem Prepares filesystem to store previews
_pdfpreview_realpath

Constants

Namesort descending Description
PDFPREVIEW_DEFAULT_QUALITY
PDFPREVIEW_DEFAULT_SHOW_DESCRIPTION
PDFPREVIEW_DEFAULT_SIZE
PDFPREVIEW_DEFAULT_TAG
PDFPREVIEW_FILENAMES_HUMAN
PDFPREVIEW_FILENAMES_MACHINE