download_manager.module

<?php
/**
 * @file
 * Enables counting how many times a node's download link(s) has been clicked.
 * Also includes a form wizard for downloading.
 */

// TODO: Better way to handle this?
define('PERSONAL_USE_LICENSE_ID', 0);
define('COMMERCIAL_USE_LICENSE_ID', 1);

/**
 * Implements hook_menu().
 */
function download_manager_menu() {
  $items['download-manager/%ctools_js/download/%'] = array(
    'title' => 'Go to the download form for a particular node.',
  	'page callback' => 'download_manager_wizard',
  	'page arguments' => array(1, 3), // %ctools_js, %nid
  	'access callback' => TRUE,
    'type' => MENU_CALLBACK,
    'file' => 'download_manager_wizard.inc',
  );
  $items['download-manager/process-download/%node/%/%user/%/%'] = array(
    'title' => 'Process a download.',
  	'page callback' => 'download_manager_process_download',
  	'page arguments' => array(2, 3, 4, 5),  // %nid, %license_id, %uid, %price
  	'access callback' => 'download_manager_process_download_access',
  	'access arguments' => array(4, 6),      // %uid, $session_token  
    'type' => MENU_CALLBACK,
  );  
  return $items;
}

/**
 * Implements hook_node_load().
 * TODO: do we really need to implement hook_node_load?
 */
function download_manager_node_load($nodes, $types) {  
  // Get the global tid values for personal and commercial use licenses
  $personal_use_license_id = 0;
  $commercial_use_license_id = 1;
    
  $result = db_query("SELECT downloads_total, downloads_month, downloads_week, downloads_day 
  										FROM {download_manager_downloads_counted} 
  										WHERE nid IN(:nids) AND license_id = :license_id", 
                      array(':nids' => array_keys($nodes), ':license_id' => $personal_use_license_id));
  
  foreach ($result as $record) {
    $downloads['by_license_id'][$personal_use_license_id]['downloads_total'] = $record->downloads_total;
  }  
  
//  $node->download_count = $result->fetchField();
//  if ($node->download_count === FALSE) {
//    $node->download_count = 0;
//  }
}

/**
 * Implements hook_node_delete().
 */
function download_manager_node_delete($node) {
  db_delete('download_manager_downloads')
  ->condition('nid', $node->nid)
  ->execute();
  
  db_delete('download_manager_downloads_counted')
  ->condition('nid', $node->nid)
  ->execute();
}

/**
 * Implements hook_views_api().
 */
function download_manager_views_api() {
  return array(
    'api' => 2.0,
  );
}

/**
 * Choose license form.
 */
function download_manager_download_form($form, &$form_state, $nid) {
  
//      drupal_add_js('misc/ajax.js');  
//   ctools_include('ajax');
//   ctools_include('modal');
//   ctools_modal_add_js();
// //   ctools_include('form');
//    drupal_add_js('misc/jquery.form.js');
//    ctools_add_js('ajax-responder');  
  
  $node = node_load($nid);
  
  // ---------------------------------------------------------------------------
  // Get license options
  $licenses = array();
  foreach ($node->field_license['und'] as $l) {
    $licenses[] = $l['value'];
  }  
  
  // Define options array
  $license_options = array();
  
  // Personal use
 	if (in_array(PERSONAL_USE_LICENSE_ID, $licenses)) {
 	  $personal_use_price = $node->field_personal_use_price['und']['0']['value'];
 	  if ($personal_use_price == 0) {
 	    $personal_use_price_text = '<span>FREE</span>';
 	  }
 	  else {
 	    $personal_use_price_text = '$' . $personal_use_price;
 	  } 	  
 	  $license_options[PERSONAL_USE_LICENSE_ID] = $personal_use_price_text . ' | Personal Use Unlimited';
 	} 
 	
 	// Commmercial use
 	if (in_array(COMMERCIAL_USE_LICENSE_ID, $licenses)) {
 	  $commercial_use_price = $node->field_commercial_use_price['und']['0']['value'];
 	  if ($commercial_use_price == 0) {
 	    $commercial_use_price_text = '<span>FREE</span>';
 	  }
 	  else {
 	    $commercial_use_price_text = '$' . $commercial_use_price;
 	  }
 	  $license_options[COMMERCIAL_USE_LICENSE_ID] = $commercial_use_price_text . ' | Commercial Use Unlimited';
 	}
 	
 	// Remove personal use if same price as commercial
 	if ($personal_use_price == $commercial_use_price) {
 	  unset($license_options[PERSONAL_USE_LICENSE_ID]);
 	}
 	
 	// Default value
 	$default_value = key($license_options);
 	
 	// ---------------------------------------------------------------------------
 	// Build form	
  $form['license'] = array(
      '#type' => 'radios',
      '#options' => $license_options,
      '#default_value' => $default_value,      
      '#required' => TRUE,
  );  
  
  $form['personal_use_price'] = array(
      '#type' => 'value',
      '#value' => $personal_use_price,
  );
  
  $form['commercial_use_price'] = array(
      '#type' => 'value',
      '#value' => $commercial_use_price,
  );
  
  $form['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Download'),
      '#attributes' => array(
          'class' => array('ctools-use-modal'),
      ),      
  );  
  
  $form['#action'] = url('download-manager/nojs/download/122');

	// %nid, %license_id, %uid, %price
//   $form['#action'] = url('download-manager/process-download/' . $node . '/' . $licen/%user/%/%');
  
  return $form;
}

/**
 * Implementation of hook_form_alter
 */
// function download_manager_form_alter(&$form, &$form_state, $form_id) {
//   switch($form_id) {
//   	case 'download_manager_download_form':
//   	  $form['#action'] = url('download-manager/ajax/download/122');
//   	  break;
//   }
// }

/**
 * License has been selected, now update our download_object accordingly.
 */
// function download_manager_download_form_submit(&$form, &$form_state) {
//   dsm($form_state);
//   global $user;
//   $session_token = drupal_get_token($user->uid);

//   // Construct the process_download callback url
//   global $user;
//   $nid = $form_state['build_info']['args']['0'];
//   $license_id = $form_state['values']['license'];
//   $uid = $user->uid;
//   if ($form_state['values']['license'] == '0') {
//     $price = $form_state['values']['personal_use_price'];
//   }
//   else {
//     $price = $form_state['values']['commercial_use_price'];
//   }   
// 	$session_token = drupal_get_token($user->uid);
//   $process_download_path = "/download-manager/process-download/$nid/$license_id/$uid/$price/$session_token";  
  
//  	$form_state['redirect'] = array(
//     // $path
//     $process_download_path,
//     // $options
//     array('query' => array('key' => 'value')),
//     // $http_response_code
//     302,
//   );	
  
// }

/**
 * Process download. Callback that handles access control, and the actual file transfer.
 */
function download_manager_process_download($node, $license_id, $account, $price) {
  // ---------------------------------------------------------------------------
  // Log the download in the database  
  // This is equivalent to INSERT... ON DUPLICATE KEY UPDATE count=count+1
  $id = db_merge('download_manager_downloads')
  ->key(array('nid' => $node->nid, 'license_id' => $license_id, 'uid' => $account->uid))
  ->insertFields(array(  // 'insertFields' acts only on insert
    'nid' => $node->nid,
    'license_id' => $license_id,
    'uid' => $account->uid,
  	'price' => $price,
    'count' => 1,
  ))
  ->fields(array(        // 'fields' acts on insert or update
    'timestamp' => REQUEST_TIME,
  ))  
  ->expression('count', 'count + :inc', array(':inc' => 1))
  ->execute();  
  
  // Update the downloads_counted table as well (this table is then cleaned of old data on cron run).
  // TODO: should I do this, or just update this table on cron run? Less expensive...
  $id = db_merge('download_manager_downloads_counted')
  ->key(array('nid' => $node->nid, 'license_id' => $license_id))
  ->insertFields(array(
    'nid' => $node->nid,
    'license_id' => $license_id,
    'uid' => $node->uid,
    'downloads_total' => 1,
    'downloads_month' => 1,
    'downloads_week' => 1,
    'downloads_day' => 1,  
  ))
  ->expression('downloads_total', 'downloads_total + :inc', array(':inc' => 1))
  ->expression('downloads_month', 'downloads_month + :inc', array(':inc' => 1))
  ->expression('downloads_week', 'downloads_week + :inc', array(':inc' => 1))
  ->expression('downloads_day', 'downloads_day + :inc', array(':inc' => 1))
  ->execute();    
  
  // ---------------------------------------------------------------------------
  // TODO: need a dynamic function to get the uri... check for psd if available, check node type, etc.
  $download_uri = $node->field_image['und']['0']['uri'];    
  
  // Start the file transfer, with headers designed to force file transfer 
  // (so images aren't opened by the browser)
  $content_disposition = 'attachment; filename="' . basename($download_uri) . '"';
  $headers = array
  (
  	'Content-type' => 'application/octet-stream',
  	'Content-Disposition' => $content_disposition,
    'Content-Transfer-Encoding' => 'binary',
  );    
  file_transfer($download_uri, $headers);
}

/**
 * process_download access control.
 */
function download_manager_process_download_access($account, $token = NULL) {
  // TODO: custom access denied message with contact form.
  global $user;
  
  // Check the validity of the user account.
  if ($account->uid == 0 || $account->uid != $user->uid) {
    return FALSE;
  }
  
  // Check the validity of the callback token.
  if (empty($token) || !drupal_valid_token($token, $account->uid)) {
    return FALSE;
  }
  
  // TODO: check if the user has paid for this download
  return TRUE;
}