javascript以读取新的rss条目并创建通知

Question

I want to create a javascript which checks if a new rss feed has been updated and display a notification using phonegaps notification methods. http://docs.phonegap.com/phonegap_notification_notification.md.html#Notification

     var oldEntry="";
 document.addEventListener("deviceready", onDeviceReady, false);

    // PhoneGap is ready
    //
    function onDeviceReady() {
        // Empty
    }

    // Show a custom alert
    //

    function sendRequest(){

      getRss("http://rss.cnn.com/rss/cnn_latest.rss.xml");      
      setTimeout('showAlert(newEntry.title)',4000);

    }


    function showAlert(data) {
     var st = randomString();
     if(oldEntry==""){
        oldEntry = data;
        navigator.notification.alert(
                data,  // message
                'New Rss Entry',            // title
                'New Rss Entry'              


        );        
     }

     else {
       if(oldEntry!=data){
        navigator.notification.alert(
                data,  // message
                'New Rss Entry',            // title
                'New Rss Entry'              


        );
        oldEntry = data;

       }
       }

       setTimeout('sendRequest()',8000);
    }

    function randomString() {
        var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
        var string_length = 8;
        var randomstring = '';
        for (var i=0; i<string_length; i++) {
            var rnum = Math.floor(Math.random() * chars.length);
            randomstring += chars.substring(rnum,rnum+1);
        }
        return randomstring;
    }

   sendRequest();

Right now both new along with the old Rss title pops up as notification, is it possible to restrict the function to display only the latest Rss title ?

And even after I dismiss both the notification after 8000 ms they both appear again, but I want to check if there are any new notifications and display only them, not the one s the user has dismissed.

This is for getting the newentry.

    var newEntry="";
        function getRss(url){
        if(url == null) return false;

                    // Create Google Feed API address
                    var api = "http://ajax.googleapis.com/ajax/services/feed/load?v=1.0&callback=?&q="
    + encodeURIComponent(url);

                    api += "&output=json_xml"

                    // Send request
                    $.getJSON(api, function(data){

                        // Check for error
                        if (data.responseStatus == 200) {

                            // Process the feeds
                            _process(data.responseData);

                        } 
                                  else {

                        };
                    });             

        }

        var _process = function(data) {

                // Get JSON feed data
                var feeds = data.feed;
                if (!feeds) {
                    return false;
                }

// Get XML data for media (parseXML not used as requires 1.5+)
                var xml = getXMLDocument(data.xmlString);
                var xmlEntries = xml.getElementsByTagName('item');
                var entry = feeds.entries[0];
                newEntry = entry;

            };

Answer 1

there could be many problems. I think maybe you are hitting a caching error. so try adding this -

api += "&tempVar=" + Math.random()

right after your code -

api += "&output=json_xml"