JavaScript window.open only if the window does not already exist

Question

I have an application that opens a new window on clicking a link. This spawns a page that holds a Java applet. The problem I am having is that clicking the same link reloads

Answer 1

You need to perform 2 tests... 1 check if the popup window is defined, and 2 check if it was closed.

if(typeof(winRef) == 'undefined' || winRef.closed){
  //create new
  winRef = window.open(....);
} else {
  //it exists, load new content (if necs.)
  winRef.location.href = 'your new url';
  //give it focus (in case it got burried)
  winRef.focus();
}

Answer 2

I'd do it like this - basically store all the referenced opened windows on the function itself. When the function fires, check if the window doesn't exist or has been close - of so, launch the popup. Otherwise, focus on the existing popup window for that request.

function launchApplication(l_url, l_windowName)
{
  if ( typeof launchApplication.winRefs == 'undefined' )
  {
    launchApplication.winRefs = {};
  }
  if ( typeof launchApplication.winRefs[l_windowName] == 'undefined' || launchApplication.winRefs[l_windowName].closed )
  {
    var l_width = screen.availWidth;
    var l_height = screen.availHeight;

    var l_params = 'status=1' +
                   ',resizable=1' +
                   ',scrollbars=1' +
                   ',width=' + l_width +
                   ',height=' + l_height +
                   ',left=0' +
                   ',top=0';

    launchApplication.winRefs[l_windowName] = window.open(l_url, l_windowName, l_params);
    launchApplication.winRefs[l_windowName].moveTo(0,0);
    launchApplication.winRefs[l_windowName].resizeTo(l_width, l_height);
  } else {
    launchApplication.winRefs[l_windowName].focus()
  }
}

Answer 3

Try checking:

if (!winref || winref.closed || !winref.document) { }

Answer 4

Working code

var newwindow = null;
function popitup(url) {
    if ((newwindow == null) || (newwindow.closed)) {
        newwindow=window.open(url,'Buy','width=950,height=650,scrollbars=yes,resizable=yes');
        newwindow.focus();
    } else {
        newwindow.location.href = url;
        newwindow.focus();    
    }
}  

Answer 5

You can use something like this in the page that opens the new window:

var newWindow = null;

function launchApplication()
{
  // open the new window only if newWindow is null (not opened yet)
  // or if it was closed
  if ((newWindow == null) || (newWindow.closed))
    newWindow = window.open(...);
}

Answer 6

You could check like this:

if(!winref || winref.closed)
{
}