Realtime PHP scripting

ryan_dodd

hello everyone,
i have been searching for a way to develop a web app that displays data from a postgresql db in realtime. i.e. when someone updates a number in the database, the script will go back to the db every 5-10 seconds and update these numbers on the users' screens. does anyone know of a way to do this without jdbc? thanks

jeremuck

could you describe what you are trying to do a little bit more.

Offhand, I could suggest a cronjob that runs every minute or so.

Or you can have a script that runs in an infinite loop:

while(1)
{
if(!update)
{
continue;
}
else
{
// do something
}

}

is this something you want to run in a browser, or something you want in the commandline?

ryan_dodd

thanks for replying - i will most def clarify

i want there to be a count on the page something like:

Tickets: 54

where "54" is a meaningful number brought from a database. usually what would happen is when the client side loads, it goes and gets the number 54 from the db and turns it into html to view. however, i would like to have a way to goto the database every few seconds to check and see if the meaningful number has been changed and update it on the page without refreshing or going to another page. i appreciate all the help i can get - i was thinking about the infinite loop but not quite sure if it would work b/c it would just keep looping on the page and freeze it up. also - i would like to steer clear of jdbc if at all possible.

someone said it was possible w/ just javascript but messy - any help?

cheers

jweissig

Hi,

If I understand correctly you have a database which is being accessed my multiple people at one time. This database is also used to display the “current” database records. If one of these multiple users changes the said data then you would like the other clients to refresh their web browsers to show the current dataset?

That should about right?

An easy way to achieve this results would be to add a html refresh tag that will tell the browser to refresh the page every “x” number of seconds. This is a real easy way to keep all the clients in sync.

Thanks
- Justin

ryan_dodd

thank you for the comments - but in my last posting i was wondering if there was a way to view the current records WITHOUT refreshing - i.e. the information is accessed by some script that is running to update the data WITHOUT the use of the refresh or changing pages...
thanks

Jayson

Originally posted by ryan_dodd
thank you for the comments - but in my last posting i was wondering if there was a way to view the current records WITHOUT refreshing - i.e. the information is accessed by some script that is running to update the data WITHOUT the use of the refresh or changing pages...
thanks

There may be something you can do in javascript to grab the info and update the page without refreshing, but my javascript skills are limited so I don't know how that would be done. You may want to look into it though.

Or another solution is if you use frames or an iframe (neither of which I recommend) you could have a frame holding the data you want to update, and have just that part of the page refresh itself leaving the other frames alone. Kind of a sloppy solution though, especially if you don't already use frames.

jeremuck

unfortunately, there's no way to do what you want with PHP.
PHP runs on the server.
You want the client to do something, without asking the server for the page again.
Javascript is client side, and if you embed an applet, that might work also.
You need code that will execute on the client's machine.

This may sound wierd, and it's probably not the best way, but you could create a listener in PHP and have javascript that serves as a client to the listener. However, the code for this can be complex.

jweissig

hi,

How big is the record set that you would like to refresh and how many users are you talking about here. Why would you choose to have a script tell the client if the records are updated and not use the refresh option? I just want to see your side of things.

Justin

ryan_dodd

I just want to thank everyone - i was hesitant about using this site b/c in forums i either get bashed or no one answers but this is a real helpful place i found. in any case - replying to the last post-----

the recordset is just coming from a statistics table with a field in one row that is updated by users when they recieve or request an item. i want this number to update immediately when changed so that if a manager were in a workspace or reviewing certina things on one page he can see the demand shift without having to hit refresh on this webapp - that is the whole purpose behind it. hope it helps - still open for anything but i still appreciate all the help!

Ph0eniX

Simple = Good.
Why not just have your code refresh the page every 5 to 10 sec?

ryan_dodd

i would def go simple on this if this time it suited the client's needs but unfortunately the problem with that is this:

the client needs to be able to work with the desired page of material without have to refresh. if the page refreshes then i have to save every change they have made to the page in order to place it back the way it was when it refreshed and that would be even harder. so i am looking for a way to let them work uninterrupted and still get this data realtime.

thanks for the replies!

Ph0eniX

Originally posted by ryan_dodd
i would def go simple on this if this time it suited the client's needs but unfortunately the problem with that is this:

the client needs to be able to work with the desired page of material without have to refresh. if the page refreshes then i have to save every change they have made to the page in order to place it back the way it was when it refreshed and that would be even harder. so i am looking for a way to let them work uninterrupted and still get this data realtime.

thanks for the replies!

In this case you can put a self refreshing inline frame on the page (right where the ticket counter is). That way your main page will remain uninterupted while your counter gets updated. Just an idea.

jweissig

hi,

i hate to say it but what about using html frames?

Justin