Google Books and Mediawiki

Following on from the previous post, I wrote a simpe Mediawiki extension to insert a Google Book into a wiki page. Written in a few minutes, not tested much, etc.

To use this, copy the code below and save in a file googlebook.php in the extensions directory of your Mediawiki installation.

<?php
# rdmp

# Google Book extension
# Embed a Google Book into Mediawiki
#
# Usage:
# <googlebook id="OCLC:4208784" />
# 
# To install it put this file in the extensions directory 
# To activate the extension, include it from your LocalSettings.php
# with: require("extensions/googlebook.php");
 
$wgExtensionFunctions[] = "wfGoogleBook";
 
function wfGoogleBook() {
    global $wgParser;
    # registers the <googlebook> extension with the WikiText parser
    $wgParser->setHook( "googlebook", "renderGoogleBook" );
}
 
# The callback function for converting the input text to HTML output
function renderGoogleBook( $input, $argv ) 
{
 $width = 425;
 $height = 400;
 
 if (isset($argv["width"]))
 {
  $width = $argv["width"];
 }
 if (isset($argv["height"]))
 {
  $width = $argv["height"];
 }
    
 $output = '<script type="text/javascript" 
            src="http://books.google.com/books/previewlib.js">
           </script>';
 $output .= '<script type="text/javascript"> 
            GBS_insertEmbeddedViewer(\'' 
            . $argv["id"] . '\','. $width . ',' . $height . ');
           </script>';   

    return $output;
}
?>

In your LocalSettings.php file add the line

require("extensions/googlebook.php");

Now you can add a Google book to a wiki page by adding a <googlebook> tag. For example:

<googlebook id="OCLC:4208784" />

The id gives the book identifier (such as an OCLC number or a ISBN (you need to include the identifier prefix). By defaulot, the book will appear in a box 425 × 400 pixels in size. You can add optional width and height parameters to adjust this.