booklibrary.module

<?php
// $Id$
/**
 * bookLibrary Module.
 * Module that creates a personal library of books
 * Currently only a latest read block is implemented 
 * TODO create a recommended readings block
 * TODO convert books to a content type
 * TODO create a listing of books
 * TODO add amazon support for retrieving book information
 * TODO clean up code
 * 
 * @file
 */

/**
 * Implementation of hook_menu().
 * Adds a menu item to the admin site
 * to add an isbn number.
 * 
 * @return $items
 */

function bookLibrary_menu() {
  $items['admin/bookLibrary/add'] = array(
    'title' => 'bookLibrary add isbn',
    'description' => 'add book to bookLibrary module',
    'page callback' => 'bookLibrary_add_page',
    'access arguments' => array('administer site configuration'),
    'type' => MENU_NORMAL_ITEM,
  );
  
  return $items;
}

/**
 * Menu callback
 * Callback from the menu item, creates
 * a page and gets the form for the 
 * insertion of the isbn number.
 */

function bookLibrary_add_page() {
  $output = t('Add book to recommended reading');
  
  $output .= drupal_get_form('bookLibrary_addform');
  return $output;
}

/**
 * add isbn number form
 * simple form with one field for 
 * the isbn number
 */
 
function bookLibrary_addform() {
  $form['isbn'] = array(
    '#title' => t('Isbn Book number'),
  	'#type' => 'textfield',
    '#description' => t('Add the isbn number for the book that will be displayed in the recommended reading'),
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Enter'),
  );
  
  return $form;
}

/**
 * Implementation of hook_submit
 * On submit the isbn number gets stored locally
 * the function get_bookdata is called with the
 * isbn number and retrieved data from that function
 * gets stored in $book_data.
 * This object gets saved through the saveBook function
 * that gets this object as an argument.
 */
 
function bookLibrary_addform_submit($form, &$form_state) {
  $isbn = $form_state['values']['isbn'];
  
  $book_data = get_bookdata($isbn);
  saveBook($book_data);
  
  //echo $isbn;
  //echo var_dump($book_data);
  //exit;
  

}

/**
 * function get_bookdata
 * this function retrieves the bookdata when it's given
 * a isbn number. The information is retrieved from the 
 * openLibrary site. 
 * The isbn number gets cleaned up and checked if it's in
 * the isbn-10 format or isbn-13 format.
 * The resulting book information is returned by this function
 * @param $isbn
 * @return array
 */
function get_bookdata($isbn) {
  
  //clean up isbn number
  $isbn = str_replace('-', '', $isbn);
  $isbn = str_replace(' ', '', $isbn);
  
  //echo var_dump($isbn);
  
  //check if the isbn number is available
  if(!is_null($isbn)) {
    switch (strlen($isbn)) {
      case 10: 
        // if isbn-10 format this is the url to get the versions from openLibrary
        $url_bookkeys = "http://openlibrary.org/api/things?&query=".urlencode('{"type":"/type/edition", "isbn_10":"'.$isbn.'"}');
        break;
      case 13:
        //if isbn-13 format this is the url to get the versions from openLibrary
        $url_bookkeys = "http://openlibrary.org/api/things?&query=".urlencode('{"type":"/type/edition", "isbn_13":"'.$isbn.'"}'); 
        break;
    }
  }
  //query openLibrary
  
  //echo var_dump($url_bookkeys);
  $bookkeys = get_url_contents($url_bookkeys, $curltimeout);
  //echo var_dump($bookkeys);
  $obj = json_decode($bookkeys);
  $bookkeyresult = $obj->{'result'};
  
  //echo var_dump($bookkeyresult);
  
  //determine number of versions and choose first available version if none specified
  
  $bookversioncount = count($bookkeyresult);
  if($bookversion == '') $bookversion = 1;
  elseif ($bookversion > $bookversioncount) $bookversion = $bookversioncount;
  $bookversion = $bookversion-1;
  
  $bookkey = $bookkeyresult[$bookversion];
  
  $bookpage = 'http://openlibrary.org' .$bookkey;
  $curltimeout = 10;
  $url = 'http://openlibrary.org/api/get?key='.$bookkey.'&text=true';
  $bookdata = get_url_contents($url, $curltimeout);
  
  $obj = json_decode($bookdata);
  $bookdataresult = $obj->{'result'};
  //echo var_dump($bookdataresult);
  
  //isbn
  $book_info['isbn'] = $isbn;
  
  //title
  $book_info['title'] = $bookdataresult->{'title'};
  
  //subtitle
  $book_info['subtitle'] = $bookdataresult->{'subtitle'};
  
  //authors -- handle multiple
  $book_info['authors'] = $bookdataresult->{'subjects'};


  //publishers
  $book_info['publishers'] = $bookdataresult->{'publishers'};
  
  //coverimage
  
  $olnumber_begin = stripos($bookkey, "/b/") + 3;
  $olnumber = substr($bookkey, $olnumber_begin);
  
  $size = getimagesize("http://covers.openlibrary.org/b/olid/$olnumber-M.jpg");
  if($size[0] == 1){
    //TODO code for covers when no cover exists
  } else {
    $img_small  = array('URL' => 'http://covers.openlibrary.org/b/olid/'.$olnumber.'-S.jpg?default=http://wiki-beta.us.archive.org/static/images/blank.book.png');
    $img_medium = array('URL' => 'http://covers.openlibrary.org/b/olid/'.$olnumber.'-M.jpg?default=http://wiki-beta.us.archive.org/static/images/blank.book.png');
    $img_large  = array('URL' => 'http://covers.openlibrary.org/b/olid/'.$olnumber.'-L.jpg?default=http://wiki-beta.us.archive.org/static/images/blank.book.png');
				
    $book_info['images'] = array('small'  => $img_small,
	                           'medium' => $img_medium,
	                           'large'  => $img_large);
  }

  //pagination
  $book_info['pages_total'] = $bookdataresult->{'number_of_pages'};

  //publication date
  $book_info['public_date'] = $bookdataresult->{'publish_date'};

  //link to book
  $book_info['book_link'] = 'http://openlibrary.org/b/'.$olnumber;
  
  return $book_info;
  
  
}

/**
 * function get_url_contents
 * this function gets the content from the openLibrary site
 * with cURL.
 * TODO support when cURL not available
 * @param $url
 * @param $curltimeout
 * @return unknown_type
 */
function get_url_contents($url, $curltimeout) {
  $ch = curl_init($url);
  
  curl_setopt($ch, CURLOPT_HEADER, false);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $curltimeout);
  curl_setopt($ch, CURLOPT_TIMEOUT, $curltimeout);
  
  //execute request
  $output = curl_exec($ch);
  
  //close cURL session
  curl_close($ch);
  
  if($output == '') throw new Exception("open library data unavailable");
  
  return $output;
}

/**
 * function saveBook
 * 
 * function to save the book data to the database.
 * 
 * TODO save book data to a book node instead 
 * 
 * @param $bookdata
 * @return unknown_type
 */
function saveBook($bookdata) {
  
  $book_info = $bookdata;
  //echo var_dump($book_info);
  //TODO save the book to the database ..
  //TODO check if the record allready exists
  
  $table = 'bookLibrary';
  $record = new stdClass();
  $record->isbn = $book_info['isbn'];
  $record->title = $book_info['title'];
  $record->subtitle = $book_info['subtitle'];
  $record->author = $book_info['authors'][0];
  $record->publishers = $book_info['publishers'][0];
  $record->image_small = $book_info['images']['small']['URL'];
  $record->image_medium = $book_info['images']['medium']['URL'];
  $record->image_large = $book_info['images']['large']['URL'];
  $record->pages_total = $book_info['pages_total'];
  $record->publication_date = $book_info['publication_date'];
  $record->book_link = $book_info['book_link'];
  //echo var_dump($book_info['authors'][0]);
  //echo var_dump($book_info['images']);
  drupal_write_record($table, $record);
  
  
  
}

/**
 * Implementation of hook_block()
 * 
 * this creates a block with the latest added book.
 * 
 * TODO create a block with recommended books, books can be flagged as recommended
 * 
 * @param $op
 * @param $delta
 * @param $edit
 * @return unknown_type
 */
function bookLibrary_block($op ='list', $delta = 0, $edit=array()) {
  switch ($op) {
    case 'list': 
      $blocks[0]['info'] = t('Last read');
      $blocks[0]['cache'] = BLOCK_NO_CACHE;
      return $blocks;
    case 'view': 
   
        $sql = "SELECT title, author, image_medium, book_link, bid FROM {bookLibrary} ORDER BY bid DESC LIMIT 1";
        $result = db_query($sql);
        $book = db_fetch_object($result);
        $book_info[] = $book->title;
        $book_info[] = $book->author;
        $book_info[] = $book->image_medium;
        $book_info[] = $book->book_link;
        //echo var_dump($book_info);
        //echo var_dump($book);
        //exit;
        $block['subject'] = t('Last read');
        $block['content'] .= '<h4>'.$book->title.'</h4>';
        $block['content'] .= '<img src="'.$book->image_medium.'"/>';
        $block['content'] .= '<br /><a href="'.$book->book_link.'">meer</a>';
        
      
      return $block;
  }
}