Progress bar dependant on page

[Thierry]

I'm trying to make a progress bar that fills up as the page is loading.
I can do this with a bunch of set variables, but then, in total disregard of how long the page might take to load, it will always take the same amount of time.
What I need is that the bar goes from 0% at the start to 100% when the page has completed loading, whether that takes 1 second or 30 seconds.
So that would mean that if the page will take longer to load (say a heavy search query) the progress bar will fill up more slowly accordingly (like with your browser).
Is there any PHP (or javascript) function/value that can help me with this?

Currently I can only make it last for the same amount of time using a loop and then a flush.

[ToonMariner]

you could fork your script or do what everyone else does and just have an animated gif without any % loading.  The user is really only interested in teh fact that the browser isn't hanging so the gif still working away will satisfy them enough.

[Thierry]

Thats probably true, but I still want to be able to do this.
Basicly all I need is some kind of value which I can use to modify the amount of time for the bar to fill up.
(basicly some kind of indication of how long it might take to load the current page).

[hitman6003]

To do a progress bar you have to know one of two things:  the total time the script will take to execute before it executes, so you can then take the time elapsed and compare it to the time needed and give a percentage...or you need a way to measure the progress of the script, so if the script has finished 20% of itself, then you let the user know that.

[Thierry]

Any ideas on how I can figure out how long any given script is going to take? If I for instance do a search on something that yields a lot of results, then naturally the bar should fill up slower.
Any javascript or PHP value or function that can calculate the total time of the execution?

[Thierry]

Anything else then PHP javascript that can be used? Something from the system itself? (like starting a word application or something). The browser loading bar does seem dependant on page loading time so there must be something.

[hitman6003]

[quote author=Thierry link=topic=104788.msg420816#msg420816 date=1156351287]
The browser loading bar does seem dependant on page loading time so there must be something.
[/quote]

That's because it knows how much data is in/on the page...it's a part of the packet information.