PHP to limit page views to 1 user at a time?

SuprSpy79

How can I limit a page to only be viewed by 1 user at a time? Basically I need it to operate like this.

User A opens page.php - He uses that page for 60 seconds and then a javascript redirects him to an exit page (I would use php if it has a way of doing this but im not sure). While user A is on page.php, user B tries to access page.php, but since user A is currently using it, user B receives a message that he is in queue position one, and a counter counts down the amount of time till user A gets redirected. When the time is up the page refreshes and user B now has access to page.php. And so on down the line if more users try to access the page at the same time.

Any help is greatly appreciated.

Thanks

planetsim

I doubt it would be accurate however you could use a database to store pages of which each user is on. Then check again to see if the page is free. If so then they can move on if not they stay were they currently are. However like I said it will not be accurate because a user could possibly leave a page and you cannot track them if they leave unless you have an onunload to popup a page which terminates. However some browsers can block this request.

SuprSpy79

Someone suggested setting a flag in a database and then checking to see if that flag existed then taking an action, but again if the just close the page (the person that set the flag) then how do I reset it?

Plus im not that good with php so im not quite sure how to code it, but I REALLY need to get this done.

jamesm87

Hey,

One way of doing it is by doing this.

1 - User A goes on
SQL - Logs User A and Time is 0:00
2 - User B goes on and Waits
SQL - Logs User B is waiting and + 0.60 to User A
3 - User A is automatically redirected using javascript or META codes and that final page deletes the record in the db (or flags it as expired)
4 - User B, when they reach their entrance time, enters the page and removes Users A session time.

One way of monitoring this is by having a very small unseeable Iframe that automatically refreshes the whole webpage.. perhaps set it to every 5 seconds.

Just an Idea.

rehfeld

like said above. set a flag in the database when somone is viewing the page. the flag should have a timestamp associated w/ it.

when that user views another page remove any previous flag they had for another page.

whenever somone trys to access a page, you will need to first check if a flag exists for that page. if it does, then you need to check how long ago the flag was set(hence why i said you need a timestamp for each flag). if the flag was set say 15minutes ago or longer, then ignore the flag and and set a new one to allow the current user because if that old user has not been active for 15min, they likely are no longer viewing the page and have left the website. you decide how long this "timeout" period is.

this is no trivial task if your going to do it properly. if you dont really know what your doing, you might allow more than 1 person to view a page at the same time if you dont understand race conditions and all other possibilities.

why exactly do you need to allow only 1 person to view a page at a time? there may be a better, and easier solution to your problem. i would highly suggest trying to avoid having to do this unless your very confident of your capabilities.