Time Triggering

MrQ

I've searched this forum for posts that could help me out, came across several quite similar but then not exactly...

I'm working on a project currently (in planning phase at the moment), and I'm stuck :/. Basically it goes like this:

There's a web page, which contents changes according to time of day (for a good start lets limit it to day/night versions). Now the times at which the page content should change, are stored in a MySQL database (they are actually sunrise/sunset times for a given feographical lacation). Now that's were the problems arise...Is there any way of making PHP "know" at what time it should change the page contents? A complicating factor might be, that the sunset/sunrise times are different for each day, and the time difference between sunrise/sunset times does not increment arithmetically...🙁

Thanks in advance

TheDefender

That's actually not as hard as it seems, and it doesn't matter if the times are different... How are the times stored in the database?

LordShryku

Well, I assume you're storing the times as hour:minute:seconds? That's the normal time type field. Assuming a lot about your table, here's the jist:

$sql = "SELECT sunset
        FROM table
        WHERE the_date = '".date("Y-m-d")."'";
# select the sunset time for the current day
$res = mysql_query($sql) or die(mysql_error());
if(mysql_num_rows($res) > 0) {
   $row = mysql_fetch_row($res);
   $set = strtotime($row[0]); # timestamp for sunset
   if($set < time()) {
      # show the sunset page
   }
   else {
      #show the sunrise page
   }
}
else {
   echo "No results from the database";
}

This assumes a lot about your table structure and coding needs, but since you didn't really give any specific information, it's the best I could think of.

luke9_20

You're kinda cancelling out your own question... You want PHP to know what time to change your website... but you also said you have the times to change it stored in a database.... so, what's the question? Are you trying to compare the two times?

luke9_20

Ok, nevermind he's already posted a good script for you.

MrQ

luke9_20: Sorry, maybe the explanation wasn't clear enough, I wanted PHP to somehow read from the MySQL table the time at which it is supposed to generate a new page...

LordShryku: Thanks for the PHP script, I actually thought of doing this that way...however I'm not the one "in charge", and the "up above" gave a directive, that the script would perform the "time check+page generation" only once - at the time given in the SQL database (not too good at PHP but from what I understand your script would be run everytime a page request is sent to the server). So the page generation is kind of time triggered...

Sorry for all the messup (I'm not a native speaker and all), dunno if you get what I mean... :/

Rodders

So, are you trying to get a PHP script to run at a given time in the database, and that script will somehow change the content of a page or pages ?

I don't believe you can make a PHP script trigger in this way, you will need to use some kind of scheduling system. I was looking into this before, but I can't find the info right now.

Rodders

I've found the thread I started regarding this same task. Unforunately, I never went any further with it because I found a better way around my problem

CRON jobs

MrQ

Thanks for the info, but that unfortunatelly does not solve my problem as I know this page will be on an Win OS...and according to my previous research CORN is a UNIX feature...🙁

Anyone?Help?

LordShryku

Windows has a task schedular built in.

MrQ

yessss but then again as far as I recall, you can't really make the scheduling service run at the times declared in the dayabase.

thanks form the help everyone, it just seems I'll have to declare it impossible 🙂, and use something like the script given previously.

cheers

Rodders

You could write a script that continuously checks the database until it hits the trigger time, then it will run some code to effect the changes that you want.

It would mean having a continuously looping and running script, so not a great idea, but it would be an option.

Weedpacket

Originally posted by Rodders
You could write a script that continuously checks the database until it hits the trigger time, then it will run some code to effect the changes that you want.

It would mean having a continuously looping and running script, so not a great idea, but it would be an option.

Or a script that regularly (say, every hour or so - which should be frequent enough except in extreme latitudes), that will look in on the database to see if there's an upcoming sunrise/sunset event in the next hour, and schedule a one-off task appropriately if there is.

Even more elegant, combine the two: when the script runs at sunrise or sunset, it also schedules the time at which it is supposed to run next (i.e., the following sunset or sunrise).

These both assume that Windows has something analogous to Un*x's at() program that can be used.