Sample service to keep checking whether a file on a webserver has changed

Create a new DroidScript JavaScript project with the following code in the main .js file

mainApp.js

var svc;
//Called when application is started.
function OnStart()
{
    //Create a layout.
    var lay = app.CreateLayout( "linear", "VCenter,FillXY" );    
 
    //Create a 'Stop Service' button.
    var btn = app.CreateButton( "Stop Service", 0.6, -1 );
    lay.AddChild( btn );
    btn.SetOnTouch( btn_OnTouchStop );
 
    //Add layout to app.    
    app.AddLayout( lay );
 
    //Start/connect to our service.
    svc = app.CreateService( "this","this", OnServiceReady );
    //uncomment next line to cause your service to start at boot.
    //app.SetAutoBoot( "Service" );
}
 
//Called after our service has started.
function OnServiceReady()
{
    console.log( "Service Ready" );
    var running=false;
    var me=app.GetPackageName()+":droidscript_service";
    var lst = app.GetRunningServices(); 
    for (var key in lst)  
    { 
        if(lst[key].name === me) 
        {
            console.log(me + " running");
            break;
        }
    } 
}
 
function btn_OnTouchStop()
{
    //Tell service we are quitting.
    svc.SendMessage( "quit" );
    //give the service time to clean up
    setTimeout(delayedStop,1000);
 
}
 
function delayedStop()
{
    //Stop the service.
    svc.Stop();
    // exit main app
    app.Exit();
}
 
function OnData( isStartUp ) 
 
{ 
    var id=app.GetNotifyId(); 
 
    if(id === "servFilx" ) 
    { 
        app.Alert("Notification touched") ;
    } 
 
} 

Add a second file called Service.js with the following code

Service.js

var g_ = {lastResponse:""};
 
function OnStart()
{
    app.ShowPopup("Service started");
    g_.notify=app.CreateNotification();
    //Check file
    SendRequest();
    //Check again every 30 seconds
    g_.interval = setInterval(SendRequest,30000);
}
 
//Send an http get request. 
function SendRequest() 
{ 
    app.HttpRequest( "GET",
        "http://sgarman.net",
        "/downloadable.txt",
        "",
        HandleReply,
        "" ); 
} 
 
//Handle the server's reply
function HandleReply( error, response )
{
    if( !error )
    {
        if(g_.lastResponse !== response) 
        { 
           g_.lastResponse = response; 
           g_.notify.SetMessage( response, "File contents", response );  
           g_.notify.Notify("servFilx"); 
        } else console.log("same"); 
    }
    else
    {
        app.ShowPopup( "Error: " + response );
    }
}
 
//Called when we get a service message.
function OnMessage( msg )
{
    //Show debug in WiFi IDE.
    console.log( msg );
 
    //Handle messages from main App.
      if( msg=="quit" ) 
      {
          clearInterval(g_.interval);
          console.log("loop stopped");
          g_.notify.Cancel("servFilx");
      }
}