Re: How to know that a window is still open

[Gordon McComb <gmccomb@ix.netcom.com>]

FYI and FWIW: I just tested window.name on the top-level window under
Windows 95, Windows 3.1 and Macintosh (68K) and all return an empty string,
not <undefined> or null.  Can someone with a PPC Mac and various flavors of
Unix try this script and let me know the result when tested on a top-level
window?

alert (window.name);

If this is indeed a platform inconsistency we should investigate it.

-- Gordon
http://gmccomb.com/javascript/


At 08:55 PM 2/29/96 +0000, you wrote:
>
>> Few days ago I asked how to recognize that a given window is
>> the topmost window
>
>There have been a few posts in reply to this. Here's mine.
>
>      Given the following:
>
>> Weird.  The following works for me (I'm using Windows
>> 95, BTW):
>> 
>> <SCRIPT>
>** > if (window.name == "")
>> 	alert ("top level window")
>
>
>     and the following:
>
>
>> >Off the top of my head: If you open the window and
>> >pass it a name, like this:
>> >
>> >        window.open ("blah.html", "win1");
>> >
>> >then it will have a name.  You can test for the name
>> >with
>> >
>** > >        if (window.name !="")
>> >                 you're in the top window
>> >
>> >But, it doesn't work. I tried to display window.name
>> >(exactly in this example window.win1) with alert and
>> >always I'v got '<undefined>' value.
>
>
>I wouldn't trust versions of Netscape across all platforms
>to act the same. Some might return "", or undefined, or
>null in some cases. Changing the marked line of the
>script in the first example to:
>
>    if (window.name+"" == "")
>
>and the marked line of the second example to:
>
>    if (window.name+"" !="")
>
>might provide better compatibility across platforms. To convert any 
>unexpected <undefined> and null to usable values I use the following:
>
>for string (as above)
>
>    string+""   for compares and     string+=""     for assignment
>
>for numeric
>
>     value+0     for compares and     value=+0     for assignment.
>
>If  I need to compare a numeric value against its string counterpart, 
>temporarally express it as a string, or need to use it with indexOf () 
>and do not want to change the original value I will use:
>
>    value+""   
>
> or if  I want it changed to a string I'll use
>
>      value+="";
>
>And last but not least. The same as above but for numeric values I 
>use:
>
>for compares:
>
>     string*1   If  I know the string will equate to a number.
>     parseInt(string)  or  parseFloat(string)   If I'm not sure.
>
>for assignment:
>
>     string*=1   If I know the string will equate to a number.
>     string=parseInt(string)  or  string=parseFloat(string)  If I'm not sure.
>
>     Note: 'string' in the last example becomes numeric. I'm just 
>     reusing the vaiable 'string' rather than creating a new one.
>
>I'm sure everyone knows the * verses + in the above example is due to 
>JavaScript equating + to concantinate for expressions invoving a 
>string variable or literal.
>
>I gotta stop drinking so much Diet Coke. I write too much.
>
-- Gordon
http://gmccomb.com/javascript/


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