JavaScript to close child windows






4.73/5 (9 votes)
How to close open child windows when parent window is closed, using JavaScript.
How to Close Child Windows When the Parent Window Closes
The Motivation
When moving an application from Windows to web, I noticed that certain functionality available only in a Windows Form is expected to be carried over to the web form. Unfortunately, sometimes, achieving the said functionality can be a bit more difficult than expected.
The Objective
Being object oriented in nature, I wanted a drop in solution on the client side to achieve closing child windows. Doing a bit of research told me that the call to window.open
would return a window
object that I could then (at a later time) call close
on. The question to be answered was how to store each window object upon opening, and how to detect the browser closing in order to close the child windows.
Note: There are more than a few articles out there on creating objects in JavaScript, and it is beyond the scope of this article.
The Code
Persisting Window Handles
The first thing, persist the window object returned by the open
function call. I achieved this by storing it as a private Array
within my object.
function windowController(){ //Note: The absence of “this” indicates private var loadedWindows = new Array() ….. } //Note: Yes, in JavaScript an object // is declared similar to a function.
Encapsulate window.open
Now that I have a nifty array, I need a public method that would wrap the window.open
function to capture the returned object and add to my array.
this.popUpWindow = function(wndUrl, wndName, wndWidth, wndHeight){
var windObj = null;
try
{
//set default width
if(typeof wndWidth == 'undefined') wndWidth=500;
//set default height
if(typeof wndHeight == 'undefined') wndHeight=250;
windObj = window.open(wndUrl,
//misc options to open a window, again mostly optional
wndName, 'toolbar=0,menubar=0,resizable=0,location=0,
directories=0,width='+wndWidth+',height='+wndHeight);
windObj.registerID = wndName; //this is the key to the window
loadedWindows[loadedWindows.length] = windObj;
//add the window to our collection.
}
catch(ex) {
alert('WindowController.popUpWindow: ' +
'Exception occured, message: ' + ex.message)
} //oops, looks like we are cross domain scripting.
return windObj;
}
Further Enhance Encapsulation
Since I am wrapping window.open
, I decided to only allow a single instance of each handle ID to be opened, by checking the ID against each window handle already loaded, and if it exists, I simply call focus
(this is similar to what is expected from Windows Forms).
this.popUpWindow = function(wndUrl, wndName, wndWidth, wndHeight){
var windObj = null;
try{
windObj = findWindow(wndName);
if (windObj != null)
{
windObj.focus();
}
else
{
......
}
where the findWindow
function simply iterates the array, and returns null
if not found.
function findWindow(winHandle){
for (var i=0; i< loadedWindows.length; i++){
if (loadedWindows[i].closed == true){
loadedWindows.splice(i,1);
i--;
}
else{
if (loadedWindows[i].registerID == winHandle)
return loadedWindows[i];
}
}
return null;
}
Pulling it all Together
Finally, I needed a way to know when the browser was closing in order to close all my child windows. Of course, IE, compared to other browsers, has different ways to register to events, so I created a generic method to achieve this.
function WireEvent(elem,target,func){
if (elem.addEventListener)
elem.addEventListener(target, func, false); //FF
else if (elem.attachEvent)
elem.attachEvent(target, func); //IE
}
WireEvent(window,'onunload',_windowController.closeAllWindows);
where the onunload
function is handled as follows:
this.closeAllWindows = function(){
for(var x = 0; x < loadedWindows.length; x++){
try{
loadedWindows[x].close();
}
catch(err) {
alert('WindowController.closeAllWindows: ' +
'Exception occured, message: ' + err.message)
}
} //oops, cross domain scripting or window already closed etc...
}
Looks like all is in place, the last thing I needed was the ability to init the object so it would be available from code, so I added the call at the top of the js file, as follows….
var _windowController = new windowController();
Using the Object
Now, if the file is included, we have access to the window controller, so as long as all opened child windows are done through this object, we can be certain they will close upon browser exit as long as we are not cross domain.
_windowController.popUpWindow('ChildForm.aspx', 'ChildForm');