Refresh browser via cron(or not) to a different page on remote request?

Question

I need to display pages in a tutorial fashion. I looked in to netsupport, beamyourscreen and other possibilities but, I do not want the viewers to download anything. I cannot use gd / send screenshots due to audio / video instructions embedded in some of the pages.

Basically, I need the ability to "refresh" a users browser window to a different page via an interface on my end. Whether via a form submission, javascript or any other type of "controller" that allows me to change the page on the viewers browser. PERL preferred but, PHP / javascript whatever works and is cross browser. I set up a simple javascript page forward timer that "works" but, page load times and conversation interruptions are a huge factor.

The entire tutorial website will be developed around this ability.

I was looking in to curl / cron / wget methods but, found little information.

I have seen forum and chat scripts that basically perform a similar task but, there must be a simple(ish) solution in leau of hacking up another script to suit my needs.

I do not want others to control the pages either. The site really, only needs to be accessable during the tutorial however, It "could" remain web accessable as long as user interaction was normal unless (being controlled).

The initial site concept is based on instructing people how to properly introduce new pets into a home. Will be operated by a veteranarian that saved my pets life. I wanted to give something back.

Possible? I really appreciate simple examples etc...

Answer 1

You have no other way but to keep polling the server for "instructions" using javascript. No, you can't send nothing to the end user browser, neither curl nor wget.

Mainly, you'll have to set up a simple request/response protocol between the browser and the server.

If you want to go deeper, you can use something like cometd/meteord/etc. If not, a hidden iframe that reloads himself and receives pages with javascript code for the needed actions can do the trick.

Answer 2

It occurred to me that what you might want to use is HTML Push technology. Check out the wiki, they have several links. I have never used it myself

Answer 3

Another alternative.

With javascript dopolling and single character flatfile. Have a simple one character flatfile with a single var. Write it in perl (it is faster and uses less resources than php). The parent script calls a javascript variable in a flatfile. It hits the flatfile and goes wherever the var sets it. The flatfile is written to by the controller. Done.

I guess you could also rename an empty flatfile and use that as the controller. I am usure which is faster, open and read a specific file or hit the directory and return the file name. On the controller side, opening and writing to a file vs renaming a file. Maybe they counter each other in resources and time?

This way the site can act as a normal site. When you want to have remote users see a "presentation" (automatically being shown the site pages at the controllers pace), the controller activates polling and tells the viewers to push a start button. This allows a remote instructor to load pages for the viewers at his leisure.

It is a simple solution that works with nothing really sophisticated going on. No frames are needed either. Just need javascript enabled.

Any better suggestions are welcome!