Timer Function in HTA VBScript: VBScript, VBS

by: TheNauticanPosted on 2009-10-30 at 14:10:50ID: 25706828

Ya, WScript isn't available for HTA since it uses MSHTA, so you have to use a Javascript function.

Here's a smple of how I call if from my VBscript in the HTA.

If strParam = "Restore" Then
      objShell.SendKeys "{ENTER}"
      jsSleep( 1000 )
      objShell.SendKeys strAlias
      jsSleep( 500 )
      objShell.SendKeys "{TAB}{TAB}"
      jsSleep( 500 )
      objShell.SendKeys strLoc
      jsSleep( 500 )
      objShell.SendKeys "{TAB}{RIGHT}"
End If

</script>
 
<script language="javascript">
function jsSleep( iTime){
	var date = new Date();
	var curDate = null;
 
	do { curDate = new Date(); } 
	while(curDate-date < iTime);
}
 
</script>

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by: rejoinderPosted on 2009-10-30 at 14:45:45ID: 25707023

Try this...

<html>
<head>
<title>Hello</title>
<HTA:APPLICATION
	ID="objHello"
	APPLICATIONNAME="Hello"
	SCROLL="auto"
	SINGLEINSTANCE="yes"
</head>
<SCRIPT LANGUAGE="VBScript">
dim TimerID
Sub Window_OnLoad
	self.ResizeTo 200,100
	Dim objIE
	set objIE = createobject("InternetExplorer.Application")
	objIE.navigate "http://www.experts-exchange.com"
	objIE.visible = true
	DO WHILE objIE.Busy
	    TimerID = window.setInterval("Sleep",1000)
	Loop
	msgbox "done"
End Sub
 
Sub Sleep	
	window.ClearInterval(TimerID) 
End Sub
</SCRIPT>
<body>
Hello
</body>
</html>

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by: DanRollinsPosted on 2009-10-30 at 15:02:54ID: 25707097

You will want to avoid a tight loop that just checks for the elapsed time -- the CPU will peg 100% and no events can be processed.

I think the only usable option, other than the outside-the-box one that you described here:
http://www.Experts-Exchange.com/Q_24827107.html#a25683994
...is to not try to do the next step "inline." Instead, set a timer for the desired interval and exit the function. A little while later, the specified function resumes. Here's a general-purpose version of that. You pass it a function name and a duration in milliseconds. After that long, the specified function is executed.

Yes, this is awkward, but perhaps better than nothing. You will likely need to use global variable to maintain the state of your program.

In a common scenario, you will want to check a status every few seconds. In that case, your Step2() function checks the status and if good to go, moves on with the processing. If not ready, then call DelayThenDo() again (passing the "Step2()" fn again). And you might want to use code like TheNautican posted to record a "maximum delay" so that if the repeated status check contiinue to fail after, say 3 minutes, then you can stop doing them (the original sequence has, alas, failed).

function DelayThenDo( nMs, sFn ) {
    window.setTimeout( sFn, nMs );
}
 
function Step1() {
    ... do something that you know will take 20 seconds...
    DelayThenDo( 20000, "Step2();" );
}
 
function Step2() {
    ... continue what was started in step 1..
}

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by: rejoinderPosted on 2009-10-30 at 15:43:04ID: 25707242

After the coment above I tested my initial script and I see that there is a line out of sorts. If you use the code below, it will sit around till the page opens using about 10-20% CPU. Once the page is open, the CPU usage will drop to 0-1%.

The drawback here is mine has no cut off time as Dan mentioned above which might be a good idea if the page typically typically takes long to load or is unavailable.

<html>
<head>
<title>Hello</title>
<HTA:APPLICATION
	ID="objHello"
	APPLICATIONNAME="Hello"
	SCROLL="auto"
	SINGLEINSTANCE="yes"
</head>
<SCRIPT LANGUAGE="VBScript">
dim TimerID
 
Sub Window_OnLoad
	self.ResizeTo 200,100
	Dim objIE
	set objIE = createobject("InternetExplorer.Application")
	objIE.navigate "http://www.experts-exchange.com"
	objIE.visible = true
	DO WHILE objIE.Busy
		TimerID = window.setInterval("SleepTime",1000)
		window.ClearInterval(TimerID)
	Loop
	msgbox "done"
End Sub
 
Sub SleepTime
	'do nothing
End Sub
</SCRIPT>
<body>
Hello
</body>
</html>

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by: DanRollinsPosted on 2009-10-30 at 19:36:48ID: 25708107

rejoinder,
Putting a setInterval() call inside of the tight loop does not help. Note that the HTA is entriely unresponsive until the the action completes. You cannot drag or resize the window, let along click a button (e.g., a [Cancel Download] button).

Using the multi-step sequence that I suggeste, the HTA continues to function normally.

by: RobSampsonPosted on 2009-11-01 at 21:11:55ID: 25717166

Hi, in a HTA, you can use this Sub procedure.

It just shells to a Ping command which pings the local machine for a specified amount of seconds. The HTA waits for the shell to complete before continuing.

Regards,

Rob.

' instead of WScript.Sleep, use HTASleep #, eg:
HTASleep 1
 
Sub HTASleep(intSeconds)
	Set objShell = CreateObject("WScript.Shell")
	objShell.Run "ping 127.0.0.1 -n " & intSeconds + 1, 0, True
End Sub

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by: DanRollinsPosted on 2009-11-02 at 04:35:56ID: 25718794

Shelling out to execute a ping command is not much better than the original (which runs a JS script).

by: bseiberlingPosted on 2009-11-02 at 08:27:22ID: 25720798

Dan, I like where you are going with your example. It is very similar to what I found on the Scripting Guys blog. What I am struggling with is how to manipulate the window that I opened with the "window.open" statement. Is there any way to check the ReadyState or status of the window? Or am I forced to wait a pre-defined amount of time and hope that the page has loaded succesfully?

by: RobSampsonPosted on 2009-11-02 at 15:30:16ID: 25724884

bseiberling, if you launch a window with
Set objIE = CreateObject("InternetExplorer.Application")
objIE.Visible = True
objIE.Navigate "http://experts-exchange.com"

you can check the ReadyState and the Busy property of the window with

While objIE.ReadyState <> 4 And objIE.Busy = True
HTASleep 1
Wend

Regards,

Rob.

by: DanRollinsPosted on 2009-11-02 at 15:43:10ID: 25724967

bseiberling,
>>how to manipulate the window that I opened...

you have an object of type window. http://msdn.microsoft.com/en-us/library/ms535873(VS.85).aspx

As an HTA, you can do whatever you want with it. The way I handled this in an HTA was attached -- I haven't removed program-specific variables because I wanted to provide functional code. The desired status value is a member of document.

Note that I slapped a try ... catch around the status check because the document is not ready. It seems like a kludge, but it did work. The goScriptHelpers object is an ActiveX I wrote. It's not ready for publication :-)

function WaitForEeBrowserWindowReady()
{
    var fReady= false;
    var oNow= new Date();
    var nMaxTick= oNow.getTime()+ 60000; // 60 seconds
    while ( !fReady ) {
        try {
            if ( gwndEe ) {
                if ( gwndEe.document.readyState == "complete" )  {
                        fReady= true;
                }
            }
        }
        catch(e) { 
            goScriptHelpers.Sleep( 100 ); // give up a timeslice
        }
 
        oNow= new Date();
        if ( oNow.getTime() > nMaxTick ) {
            AddToLogFile( "resuming after time out. " ); 
            // alert( "page load timed out" );
            break;
        }
        //----------- if you have my ActiveX installed, use it, but no big deal if not
        if ( goScriptHelpers != null ) {
            goScriptHelpers.Sleep( 100 ); // give up a timeslice
        }
    }
 
    return( fReady );
}

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by: DanRollinsPosted on 2009-12-09 at 20:23:30ID: 26015143

My answer is best: http:#a25707097 It avoids shelling out to a DOS prompt. I also answered the follow-up (underlying) question with a complete example.

-- Dan

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Timer Function in HTA VBScript

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