Check if a window is open

[Jack]

I have a main webpage that has a list of records, each with a link to a
window.open function call. As an example, a page that opens is
editrecord.aspx?RecordID=34, and another is
editrecord.aspx?RecordID=52. If the user starts changing the contents
of the opened window, and then leaves it open and goes back to the main
page, refreshes the list, and clicks on the same record link again, it
reloads the contents of the page the user had changed, and all the
changes they made are lost. Is there a way to check to see if the
window for that record is open before we reload it, so that I can just
call the focus() function on that window instead of window.open again?

 

[Manifest Interactive]

I have a main webpage that has a list of records, each with a link to a
window.open function call. As an example, a page that opens is
editrecord.aspx?RecordID=34, and another is
editrecord.aspx?RecordID=52. If the user starts changing the contents
of the opened window, and then leaves it open and goes back to the main
page, refreshes the list, and clicks on the same record link again, it
reloads the contents of the page the user had changed, and all the
changes they made are lost. Is there a way to check to see if the
window for that record is open before we reload it, so that I can just
call the focus() function on that window instead of window.open again?

Greetings,

Here is a solution that will allow you to check to see if a child
window is open from the parent that launched it. This will bring a
focus to the child window without reloading its data:

<script language="JavaScript">
function loadUniquePage(page) {
if (opener && !opener.closed){
opener.focus();
}
else {
var myWin = window.open(page,'','width=800,height=600');
opener = myWin;
}
}
</script>

<a href="javascript:loadUniquePage('http://www.google.com')">link</a>

Notice that the link has to be formated like it is above when you
include it in your page for this to work. Just pass it the URL you want
to have opened and voila!

** NOTE: If the user refreshes the parent window, it loses all its
references to any child windows it may have had open.

I have placed this code on my server if you want to just copy the code
from there:

http://www.manifestinteractive.com/usenet/childWindow.html

Hope this helps,
- Peter Schmalfeldt

 

[RobG]

Manifest Interactive said on 17/03/2006 8:26 AM AEST:

Greetings,

Here is a solution that will allow you to check to see if a child
window is open from the parent that launched it. This will bring a
focus to the child window without reloading its data:

<script language="JavaScript">

The language attribute is deprecated, type is required:

function loadUniquePage(page) {
if (opener && !opener.closed){

Global variables should be declared with the 'var' keyword, just like
other variables, but outside the scope of other objects.

It's also a bad idea to use 'opener', which is already a DOM 0 property
of window objects - it refers to the window that opened this current
window, if there is one.

var popWin;
function loadUniquePage(page)
{
if (popWin&& !popWin.closed && popWin.focus){

Methods of host objects should be tested before use.

opener.focus();

This will not guarantee that 'opener' is brought to the front, but worth
a try. If the window is at the back, nothing will seem to be happening
for some users - no new page, no 'focused popup, nothing. They will
have to close the pop-up to get it to work again.

That may not be desirable, but it's a 'feature' of using pop-ups this way.

}
else {
var myWin = window.open(page,'','width=800,height=600');
opener = myWin;

Why create a local variable only to re-assign the reference to the
already created global variable?

popWin = window.open(page,'','width=800,height=600');

}
}
</script>

The full script:

<script type="text/javascript">
var popWin;
function popPage(url)
{
if (popWin &! popWin.closed && popWin.focus){
popWin.focus();
} else {
popWin = window.open(url,'','width=800,height=600');
}
}

<a href="javascript:loadUniquePage('http://www.google.com')">link</a>

And users without script support will see a link that does nothing.
Better to use:

<a href="http://www.google.com"
onclick="popPage(this.href);return false;">link</a>


At least then non-scripted UAs can navigate to the link.

[...]

 

[RobG]

RobG said on 17/03/2006 10:05 AM AEST:
[...]

The full script:

<script type="text/javascript">
var popWin;
function popPage(url)
{
if (popWin &! popWin.closed && popWin.focus){

Aggh, gremlins in the works...

if (popWin && !popWin.closed && popWin.focus){

popWin.focus();
} else {
popWin = window.open(url,'','width=800,height=600');
}
}
</script>

[...]

 

[Randy Webb]

RobG said the following on 3/16/2006 7:05 PM:

Manifest Interactive said on 17/03/2006 8:26 AM AEST:


And users without script support will see a link that does nothing.
Better to use:

<a href="http://www.google.com"
onclick="popPage(this.href);return false;">link</a>


At least then non-scripted UAs can navigate to the link.

And if there is an error in popPage then the JS enabled user gets nothing

<a href="..." onclick="return popPage(this.href)">

And have popPage return false at the end.

 

[Greg]

What if main page goes through a postback and the variable is lost? is
there a way to still check if a child window created using the
window.open method still exsits.

Is there a way if I know the name of the window or is there a way to
store the child window handle so that after a refresh on the main page
I can still check if that same page is still open?

Then if that is true can i still setfocus on that child window?

 

[Randy Webb]

Greg said the following on 3/17/2006 9:26 AM:

What if main page goes through a postback and the variable is lost? is
there a way to still check if a child window created using the
window.open method still exsits.

No. Once the reference is lost it is lost. You have to recreate it and
you run into the focus problem where applying focus() to the window may
focus it but doesn't bring it back to the front.

Is there a way if I know the name of the window or is there a way to
store the child window handle so that after a refresh on the main page
I can still check if that same page is still open?
No.

Then if that is true can i still setfocus on that child window?

See above.