javascript wait

[stephen.durkin]

I've gathered that javascript doesn't have a handy wait() function, so
I made the following function makeDelay() to make use of PHP's sleep(),
which then does the waiting, and responds with "done"...my problem is
that the javascript doesn't wait for makeDelay(seconds) to finish...?

makeDelay(5);
iDontWaitForNobody();

function makeDelay(seconds) {

url="make_delay.php?delay=" + seconds;
http.open("GET",url,true);

loadStatus=document.getElementById("loadStatus");

http.onreadystatechange=function() {
if (http.readyState==1) {
loadStatus.src="balls/load1.gif";
}
if (http.readyState==2) {
loadStatus.src="balls/load2.gif";
}
if (http.readyState==3) {
loadStatus.src="balls/load3.gif";
}
if (http.readyState==4) {
if(http.responseText == "done")
loadStatus.src="balls/load0.gif";
}
}
http.send(null);
}

[Rik]

st************@gmail.com wrote:

I've gathered that javascript doesn't have a handy wait() function, so
I made the following function makeDelay() to make use of PHP's
sleep(), which then does the waiting, and responds with "done"...my
problem is that the javascript doesn't wait for makeDelay(seconds) to
finish...?

Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);
--
Rik Wasmus

[Peter Michaux]

st************@gmail.com wrote:

I've gathered that javascript doesn't have a handy wait() function,

I think you mightu be looking for JavaScript's setTimeout()

Peter

[Peter Michaux]

Rik wrote:

st************@gmail.com wrote:

I've gathered that javascript doesn't have a handy wait() function, so
I made the following function makeDelay() to make use of PHP's
sleep(), which then does the waiting, and responds with "done"...my
problem is that the javascript doesn't wait for makeDelay(seconds) to
finish...?

Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);

or even just

setTimeout(iDontWaitForNobody, 5000);

[Randy Webb]

Peter Michaux said the following on 10/24/2006 11:03 PM:

Rik wrote:

>st************@gmail.com wrote:

>>I've gathered that javascript doesn't have a handy wait() function, so
I made the following function makeDelay() to make use of PHP's
sleep(), which then does the waiting, and responds with "done"...my
problem is that the javascript doesn't wait for makeDelay(seconds) to
finish...?

Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);

or even just

setTimeout(iDontWaitForNobody, 5000);

Neither of which does what the OP wanted - duplicating PHP's wait()
function which pauses execution of *all* code until the time is up.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Rik]

Peter Michaux wrote:

Rik wrote:

>st************@gmail.com wrote:

>>I've gathered that javascript doesn't have a handy wait() function,
so I made the following function makeDelay() to make use of PHP's
sleep(), which then does the waiting, and responds with "done"...my
problem is that the javascript doesn't wait for makeDelay(seconds)
to finish...?

Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);

or even just

setTimeout(iDontWaitForNobody, 5000);

True,

I usually follow this procedure though:
If it calls a function directly, quote it.
If it calls a function which name is in a variable, don't quote it
offcourse.

That way it's easier to backtrace everything if there's an error.

Wether this is good practise or not is something I don't know, I usually
don't do that much javascript :)

--
Rik Wasmus

[Rik]

Randy Webb wrote:

Peter Michaux said the following on 10/24/2006 11:03 PM:

>Rik wrote:

>>st************@gmail.com wrote:
I've gathered that javascript doesn't have a handy wait()
function, so I made the following function makeDelay() to make use
of PHP's sleep(), which then does the waiting, and responds with
"done"...my problem is that the javascript doesn't wait for
makeDelay(seconds) to finish...?
Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);

or even just

setTimeout(iDontWaitForNobody, 5000);

Neither of which does what the OP wanted - duplicating PHP's wait()
function which pauses execution of *all* code until the time is up.

Hmmmz, you've got a point.
If it's a simple halt in a function, you could call a second function that
takes over like this. If one wants to stop all code, that would require all
events fired be focusing/moving/etc. will have to stop.

I really don't know enough js to even start to consider how that second
option could be implemented...
--
Rik Wasmus

[Peter Michaux]

Randy Webb wrote:

Peter Michaux said the following on 10/24/2006 11:03 PM:

Rik wrote:

st************@gmail.com wrote:
I've gathered that javascript doesn't have a handy wait() function, so
I made the following function makeDelay() to make use of PHP's
sleep(), which then does the waiting, and responds with "done"...my
problem is that the javascript doesn't wait for makeDelay(seconds) to
finish...?
Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);

or even just

setTimeout(iDontWaitForNobody, 5000);

Neither of which does what the OP wanted - duplicating PHP's wait()
function which pauses execution of *all* code until the time is up.

True but since the OP didn't state the goal it could be that setTimeout
does exactly what he wants in this case. But maybe not.

Using the Internet to create the wait seems like a bad way to go since
the timing wouldn't be controllable.

I bet there is a setTimeout solution if the OP knows about it and
thinks about the problem with setTimeout in mind.

Peter

[Randy Webb]

Peter Michaux said the following on 10/24/2006 11:41 PM:

Randy Webb wrote:

>Peter Michaux said the following on 10/24/2006 11:03 PM:

>>Rik wrote:
st************@gmail.com wrote:
I've gathered that javascript doesn't have a handy wait() function, so
I made the following function makeDelay() to make use of PHP's
sleep(), which then does the waiting, and responds with "done"...my
problem is that the javascript doesn't wait for makeDelay(seconds) to
finish...?
Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);
or even just

setTimeout(iDontWaitForNobody, 5000);

Neither of which does what the OP wanted - duplicating PHP's wait()
function which pauses execution of *all* code until the time is up.

True but since the OP didn't state the goal it could be that setTimeout
does exactly what he wants in this case. But maybe not.

Using the Internet to create the wait seems like a bad way to go since
the timing wouldn't be controllable.

It's a bad idea, period, because a true wait() locks up the browser. The
time is very controllable though. And, that is very easy to test.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Randy Webb]

Rik said the following on 10/24/2006 11:36 PM:

Randy Webb wrote:

>Peter Michaux said the following on 10/24/2006 11:03 PM:

>>Rik wrote:
st************@gmail.com wrote:
I've gathered that javascript doesn't have a handy wait()
function, so I made the following function makeDelay() to make use
of PHP's sleep(), which then does the waiting, and responds with
"done"...my problem is that the javascript doesn't wait for
makeDelay(seconds) to finish...?
Don't do that.
Use setTimeout();

In this case:
setTimeout("iDontWaitForNobody()",5000);
or even just

setTimeout(iDontWaitForNobody, 5000);

Neither of which does what the OP wanted - duplicating PHP's wait()
function which pauses execution of *all* code until the time is up.

Hmmmz, you've got a point.
If it's a simple halt in a function, you could call a second function that
takes over like this. If one wants to stop all code, that would require all
events fired be focusing/moving/etc. will have to stop.

Not really. If you had a true wait(), then all execution *will* stop
because that is what wait() does. After the sleep is finished, its a rat
race as to what events will still fire and in what order, but they
should fire in the order they were initiated.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Laurent Bugnion]

Hi,

Rik wrote:

Peter Michaux wrote:

>or even just

setTimeout(iDontWaitForNobody, 5000);

True,

I usually follow this procedure though:
If it calls a function directly, quote it.
If it calls a function which name is in a variable, don't quote it
offcourse.

That's not what setTimeout(iDontWaitForNobody, 5000) does. It gives to
the setTimeout function a reference to the iDontWaitForNobody function
(which is an object, because in JavaScript, functions are objects). If
you're familiar with C#, think of it as a delegate (though it's actually
much more direct, and also much older than delegates).

For parameter-less methods, this way is faster, since the statement
doesn't need to be parsed and evaluated.

For methods with parameters, it doesn't work, but then you can use closure.

HTH,
Laurent
--
Laurent Bugnion, GalaSoft
Software engineering: http://www.galasoft-LB.ch
PhotoAlbum: http://www.galasoft-LB.ch/pictures
Support children in Calcutta: http://www.calcutta-espoir.ch

[Laurent Bugnion]

Hi,

st************@gmail.com wrote:

I've gathered that javascript doesn't have a handy wait() function, so
I made the following function makeDelay() to make use of PHP's sleep(),
which then does the waiting, and responds with "done"...my problem is
that the javascript doesn't wait for makeDelay(seconds) to finish...?

makeDelay(5);
iDontWaitForNobody();

function makeDelay(seconds) {

url="make_delay.php?delay=" + seconds;
http.open("GET",url,true);

loadStatus=document.getElementById("loadStatus");

http.onreadystatechange=function() {
if (http.readyState==1) {
loadStatus.src="balls/load1.gif";
}
if (http.readyState==2) {
loadStatus.src="balls/load2.gif";
}
if (http.readyState==3) {
loadStatus.src="balls/load3.gif";
}
if (http.readyState==4) {
if(http.responseText == "done")
loadStatus.src="balls/load0.gif";
}
}
http.send(null);
}

The reason why it doesn't work is that you call the web service method
in an asynchronous way. XmlHttpRequest also supports synchronous calls,
but I really, really recommend against it in most cases. JavaScript is
not multi-threaded, so if you let one thread sleeps, everything sleeps.

Use timers instead, like others recommended.

HTH,
Laurent
--
Laurent Bugnion, GalaSoft
Software engineering: http://www.galasoft-LB.ch
PhotoAlbum: http://www.galasoft-LB.ch/pictures
Support children in Calcutta: http://www.calcutta-espoir.ch

[Rik]

Laurent Bugnion wrote:

(which is an object, because in JavaScript, functions are objects).

Check, you're right.
--
Rik Wasmus

[Peter Tran]

If you really want to do it the way you are doing it, just change the
following line:

From:
http.open("GET",url,true);

To:
http.open("GET",url,false);

This will make the call syncrhonous...

*** Sent via Developersdex http://www.developersdex.com ***

[Laurent Bugnion [MVP]]

Hi,

Peter Tran wrote:

>
If you really want to do it the way you are doing it, just change the
following line:

From:
http.open("GET",url,true);

To:
http.open("GET",url,false);

This will make the call syncrhonous...

You should quote what you reply to.

Also, I know how to make a synchronous call. You're replying to the
wrong person. That all makes your post quite difficult to understand.

HTH,
Laurent
--
Laurent Bugnion [MVP ASP.NET]
Software engineering, Blog: http://www.galasoft-LB.ch
PhotoAlbum: http://www.galasoft-LB.ch/pictures
Support children in Calcutta: http://www.calcutta-espoir.ch