Source for file Basket.class.php

<?php
/**
 * @since 8/5/05
 * @package polyphony.basket
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: Basket.class.php,v 1.17 2007/09/19 14:04:43 adamfranco Exp $
 */ 
 
/**
 * A Basket is a session-persistant ordered collection of Asset Ids. Items can be
 * added and removed from it, as well as its contents viewed.
 * 
 * @since 8/5/05
 * @package polyphony.basket
 * 
 * @copyright Copyright &copy; 2005, Middlebury College
 * @license http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)
 *
 * @version $Id: Basket.class.php,v 1.17 2007/09/19 14:04:43 adamfranco Exp $
 */
class Basket 
    extends OrderedSet
{
        
/*******************************************************
 * Class Methods - Instance-Creation/Singlton
 *********************************************************/
 
 
    /**
     * Get the instance of the Basket.
     * The Basket class implements the Singleton pattern. There is only ever
     * on instance of the Basket object and it is accessed only via the
     * Basket::instance() method.
     * 
     * @return object Basket 
     * @access public
     * @since 5/26/05
     * @static
     */
    function instance () {
        if (!isset($_SESSION['__basket'])) {
            $_SESSION['__basket'] = new Basket();
        }
        
        return $_SESSION['__basket'];
    }
 
/*******************************************************
 * Instance Methods
 *********************************************************/
    
 
    /**
     * The constructor.
     * @access public
     * @return void 
     ***/
    function Basket() {
        // Verify that there is only one instance of Harmoni.
        $backtrace = debug_backtrace();
        if (false && $GLOBALS['BASKET_INSTANTIATED'] 
            || !(
                strtolower($backtrace[1]['class']) == strtolower('Basket')
                && $backtrace[1]['function'] == 'instance'
//                 && $backtrace[1]['type'] == '::'    // PHP 5.2.1 seems to get this wrong
            ))
        {
            die("\n<dl style='border: 1px solid #F00; padding: 10px;'>"
            ."\n\t<dt><strong>Invalid Basket instantiation at...</strong></dt>"
            ."\n\t<dd> File: ".$backtrace[0]['file']
            ."\n\t\t<br/> Line: ".$backtrace[0]['line']
            ."\n\t</dd>"
            ."\n\t<dt><strong>Access Basket with <em>Basket::instance()</em></strong></dt>"
            ."\n\t<dt><strong>Backtrace:</strong></dt>"
            ."\n\t<dd>".printDebugBacktrace(debug_backtrace(), true)."</dd>"
            ."\n\t<dt><strong>PHP Version:</strong></dt>"
            ."\n\t<dd>".phpversion()."</dd>"
            ."\n</dl>");
        }
        
        
        $idManager = Services::getService("Id");
        $this->OrderedSet($idManager->getId("__basket"));    
    }
    
    /**
     * removes unauthorized assets from the basket
     * 
     * @return void 
     * @access public
     * @since 12/14/05
     */
    function clean () {
        $authZ = Services::getService("AuthZ");
        $idManager = Services::getService("Id");
 
        $this->reset();
        while ($this->hasNext()) {    
            $id =$this->next();
            if (!$authZ->isUserAuthorized(
                $idManager->getId("edu.middlebury.authorization.view"), $id))
            {
                $this->removeItem($id);
                $this->reset();
            }
        }
        $this->reset();
    }
    
    /**
     * Return an XHTML string of a small version of the basket for use in a header.
     * Includes a link and the number of items in it.
     * 
     * @param integer $level The level of component to return
     * @return object Component 
     * @access public
     * @since 8/5/05
     */
    function getSmallBasketBlock ($level = ALERT_BLOCK) {
        $block = new Block(
            "<div id='basket_small'>\n".$this->getSmallBasketHtml()."\n</div>", 
            $level);
        
        // controlling JS
        ob_start();
        $harmoni = Harmoni::instance();
        
        $placeHolderUrl = POLYPHONY_PATH."/icons/1x1.png";
        
        $harmoni->request->startNamespace("basket");
        $addBasketURL = str_replace("&amp;", "&", 
            $harmoni->request->quickURL("basket", "addAjax", array("assets" => "xxxxx")));
        $emptyBasketURL = str_replace("&amp;", "&", 
            $harmoni->request->quickURL("basket", "emptyAjax"));
        $harmoni->request->endNamespace();
        
        print<<<END
 
<script type='text/javascript'>
// <![CDATA[
 
    /**
     * Basket class
     * Contains functions for interacting with the basket
     * 
     * @since 5/5/06
     */
    function Basket () {
        
    }
    
    /**
     * Add the asset ids to the basket and refresh the basket contents
     * 
     * @param array idArray
     * @return void
     * @access public
     * @since 5/2/06
     */
    Basket.addAssets = function ( idArray ) {
        if (idArray.length == 0)
            return;
            
        
        // Get the basket element
        var basketElement = document.get_element_by_id('basket_small');
        var basketContentsElement = document.get_element_by_id('basket_small_contents');
        
        // Add placeholders to the basket
        for (var i = 0; i < idArray.length; i++) {
            var elem = document.createElement('img');
            elem.style.border = '1px solid';
            elem.style.margin = '2px';
            elem.style.marginRight = '1px';
            elem.style.height = '60px';
            elem.style.width = '60px';
            elem.style.verticalAlign = 'middle';
            elem.src = '$placeHolderUrl';
            basketContentsElement.appendChild(elem);
            basketContentsElement.appendChild(document.createTextNode("\\n"));
        }
        
        // Build the destination url
        var addBasketURL = new String('$addBasketURL');
        var regex = new RegExp("xxxxx");
        addBasketURL = addBasketURL.replace(regex, idArray.join(','));
        Basket.reload(addBasketURL);
    }
    
    /**
     * Empty the basket and refresh the small basket contents
     * 
     * @return void
     * @access public
     * @since 5/5/06
     */
    Basket.empty = function () {
        Basket.reload('$emptyBasketURL');
    }
    
    /**
     * Reload the small basket display via AJAX
     * 
     * @param string url
     * @return void
     * @access public
     * @since 5/5/06
     */
    Basket.reload = function ( url ) {
        /*********************************************************
         * Do the AJAX request and repopulate the basket with 
         * the contents of the result
         *********************************************************/
                    
        // branch for native XMLHttpRequest object (Mozilla, Safari, etc)
        if (window.XMLHttpRequest)
            var req = new XMLHttpRequest();
            
        // branch for IE/Windows ActiveX version
        else if (window.ActiveXObject)
            var req = new ActiveXObject("Microsoft.XMLHTTP");
        
        
        if (req) {
            req.onreadystatechange = function () {
                // only if req shows "loaded"
                if (req.readyState == 4) {
                    // only if we get a good load should we continue.
                    if (req.status == 200) {
                        var basketElement = document.get_element_by_id('basket_small');
                        basketElement.innerHTML = req.responseText;
                        Basket.removeBorders();
                    } else {
                        alert("There was a problem retrieving the XML data:\\n" +
                            req.statusText);
                    }
                }
            }
            
            req.open("GET", url, true);
            req.send(null);
        }
    }
    
    /**
     * Remove borders from div's surrounding images (in the basket) if the 
     * images are loaded.
     * 
     * @param element parentNode
     * @return boolean True if all are loaded
     * @access public
     * @since 6/15/06
     */
    Basket.removeBoardersForCompletedImages = function (parentNode) {
        var allLoaded = true;
        for (var i in parentNode.childNodes) {
            var child = parentNode.childNodes[i];
            if (child.nodeType == 1 && child.tagName.toLowerCase() == "div") {
                for (var j in child.childNodes) {
                    var grandchild = child.childNodes[j];
                    if (grandchild.nodeType == 1 && grandchild.tagName.toLowerCase() == "img") {
                        if (grandchild.height > 0 && grandchild.width > 0) {
                            child.style.border='0px';
                            child.style.margin='3px';
                            
                            /* Resize images for IE */ 
                            if (grandchild.height > 50 || grandchild.width > 50) {
                                grandchild.width = 50;
                            }
                        } else {
                            allLoaded = false;
                        }
                    }
                }
            }
        }
        
        return allLoaded;
    }
    
    /**
     * Loop waiting for images to load and then remove their boarders if they are
     * loaded.
     * 
     * @return void
     * @access public
     * @since 6/15/06
     */
    Basket.removeBorders = function () {
        if (!Basket.removeBoardersForCompletedImages(
                    document.get_element_by_id('basket_small_contents')))
        {
            window.setTimeout('Basket.removeBorders()', 100);
        }
    }
    
// ]]>
</script>
END;
        
        $block->setPreHTML(ob_get_clean());
        
        return $block;
    }
    
    /**
     * Answer the XHTML string of the small version of the basket contents
     * 
     * @param <##> 
     * @return <##> 
     * @access public
     * @since 5/2/06
     */
    function getSmallBasketHtml () {
        $harmoni = Harmoni::instance();
        $harmoni->request->startNamespace("basket");
        
        $this->clean();
        
        ob_start();
        print "\n\t<a href='";
        print $harmoni->request->quickURL("basket", "view");
        print "'>";
        print _("Selection: ");
        print "(".$this->count()." "._("items").")";
        print "</a>";
        
        print "\n\t<div id='basket_small_contents' style='text-align: left; min-width: 200px;'>";
        $this->reset();
        $i = 0;
        if ($this->hasNext()) {
            while ($this->hasNext()) {
                $id =$this->next();
                $thumbnailURL = RepositoryInputOutputModuleManager::getThumbnailUrlForAsset($id);
                if ($thumbnailURL !== FALSE) {                
                    print "\n\t<div style='border: 1px solid; height: 60px; width: 60px; float: left; text-align: center; vertical-align: middle; padding: 0px; margin: 2px;'>";
                    
                    //  The image
                    print "\n\t\t<img class='thumbnail_image' \n\t\t\tsrc='$thumbnailURL' \n\t\t\talt='Thumbnail Image'";
                    print " \n\t\t\tstyle='max-height: 50px; max-width: 50px; vertical-align: middle; margin: 5px; cursor: pointer;'";
                    
                    // border removal
                    print " \n\t\t\tonload=\"if (this.parentNode) { this.parentNode.style.border='0px'; this.parentNode.style.margin='3px'; } /* Resize images for IE */ if (this.height > 50 || this.width > 50) {this.width = 50;}\" ";
                    
                    // Viewer Link
                    print " \n\t\t\tonclick='window.open(";
                    print '"'.VIEWER_URL."?&amp;source=";
                    print urlencode($harmoni->request->quickURL("basket", "browse_xml"));
                    print '&amp;start='.$i.'", ';
                    print '"_blank", ';
                    print '"toolbar=no,location=no,directories=no,status=yes,scrollbars=yes,resizable=yes,copyhistory=no,width=600,height=500"';
                    print ");'";
                    print "\n\t\t/>";                    
                    print "\n\t</div>";
                    
                    $i++;
                }
            }
        }
        print "\n\t</div>";
        
        print <<< END
    
    <script type='text/javascript'>
    // <![CDATA[
    
        Basket.removeBorders();
    
    // ]]>
    </script>
        
END;
        
        if ($this->count()) {
            print "\n\t<div style='text-align: right; font-size: small; clear: both;'>";
            print "<a onclick='Basket.empty()'>"._("Empty")."</a>";
            print "\n\t</div>";
        }
        
        
        $harmoni->request->endNamespace();        
        return ob_get_clean();
    }
    
    /**
     * Answer the link to add a particular id to the basket
     * 
     * @param object Id $assetId 
     * @return string XHTML
     * @access public
     * @since 5/2/06
     */
    function getAddLink ( $assetId ) {
        $harmoni = Harmoni::instance();
        $harmoni->request->startNamespace("basket");
        ob_start();
        
        print "<a ";
        print " style='cursor: pointer;'";
        print " onclick='Basket.addAssets(new Array(\"".$assetId->getIdString()."\"));'";
        print ">"._('+ Selection');
        print "</a>";
        
        $harmoni->request->endNamespace();
        $harmoni->history->markReturnURL("polyphony/basket",
            $harmoni->request->mkURLWithPassthrough());
                
        return ob_get_clean();
    }
    
}
 
?>