PHP script to pull from Facebook events from multiple pages - php

Question

Bonjour everyone,
Currently, the script below is on my server as a PHP page (pull.php). It reads the events from a Facebook page using its ID, e.g: 12345678, and outputs them to a file, e.g: 1234568.ics.
What I'd like to ask this community for help with:
1) how would one modify the code below to read from many Facebook pages (an array where I would put in the page ID manually, e.g: 12345678, 24681357, 12348765) and output to many files 12345678.ics, 24682357.ics, 12348765.ics
2) I'm looking for these .ics files to be created and updated (crushed) right on my server, at the same location as where the script runs. The idea is that I'll run a CRON job that would run this script nightly. I then have a plugin on my Facebook page that updates events on the website based on the .ics feed.
CODE:
$access_token = MY_ACCESS_TOKEN;
$page = "12345678";
// We don't want to query the Facebook Graph API over and over, so we'll cache our results. You can force the cache to update by visiting the script and appending "?f=true", otherwise it will only run (rather than display the cache) if the cache is older than 3600 seconds (one hour).
$cache = $page . ".cache";
$f = false;
if($_GET['f'] == "true"){
$f = true;
}
if(!file_exists($cache) || filemtime($cache) <= time()-3600 || $f){
// Get and decode the data - your page's event list - from the API
$graph_url = "https://graph.facebook.com/" . $page . "/events?access_token=" . $access_token;
$data = file_get_contents($graph_url);
$data = json_decode($data);
if(!empty($data->error)){
echo '<b>$data error</b><br />';
echo $data->error->type . " error (" . $data->error->code . "/" . $data->error->error_subcode . "): " . $data->error->message;
exit;
}
// Go through the list of events, and get and decode more detailed information on each event.
foreach ($data->data as $event){
$event_data = file_get_contents("https://graph.facebook.com/" . $event->id . "?access_token=" . $access_token);
$event_data = json_decode($event_data);
if(!empty($event_data->error)){
echo '<b>$event_data error</b><br />';
echo $event_data->error->type . " error (" . $event_data->error->code . "/" . $event_data->error->error_subcode . "): " . $event_data->error->message;
exit;
}
// Store it in an array for later use.
$events[] = $event_data;
}
// We're now done fetching the data from Facebook's Graph API. Now we'll have to create an iCal file.
// This requires the iCalcreator PHP class, which you can downloead from kigkonsult at kigkonsult.se/iCalcreator/index.php
require_once("icalcreator/iCalcreator.class.php");
// Create the calendar, set up some basic properties
$c = new vcalendar(array('unique_id' => $page));
$c->setProperty('X-WR-CALNAME', $page . ' events');
$c->setProperty('X-WR-CALDESC', 'Facebook events for ' . $page);
$c->setProperty('X-WR-TIMEZONE', $events[0]->timezone); // We assume all of the events use the same timezone.
// Loop through the events, create event components in the calendar
foreach($events as $key => $event){
$e[$key] = & $c->newComponent('vevent');
$e[$key]->setProperty('summary', $event->name);
$e[$key]->setProperty('dtstart', $event->start_time);
$e[$key]->setProperty('dtend', $event->end_time);
if (!isset($event->end_time)) {
$e[$key]->setProperty('dtend', $event->start_time);
}
$e[$key]->setProperty('description', $event->description . "\n\nhttp://www.facebook.com/events/" . $event->id);
$e[$key]->setProperty('location', $event->location);
}
// Remove the cache if it exists
if(file_exists($cache)){
unlink($cache);
}
// Open (create) the cache file
if(!$handle = fopen($cache, 'w')){
echo "Cannot open output file: " . $cache;
exit;
}
// Write the calendar to the cache
if(fwrite($handle, $c->createCalendar()) === FALSE){
echo "Cannot write to output file: " . $cache;
exit;
}
// Close the cache file
fclose($handle);
}
// Now we've got the calendar in the cache file, either newly generated and stored there just a few lines ago or from earlier. Now we'll just display it.
header("Content-Type: text/calendar; charset=UTF-8");
header("Content-Disposition: filename=" . $page . ".ics");
require($cache);
?>
Might anyone have a clue how to do this?
Thanks in advance! Upvotes your way if you can help me out!

Answer 1

You can use a FQL query to get results for multiple pages at once, like this:
select eid, creator, name, description, start_time, end_time, timezone, location from event where creator in ({PAGE1_ID}, {PAGE2_ID}, ...) and start_time > now() order by creator asc
You can issue the (URL encoded) query via the
GET /fql?q=...
endpoint like this (replace Page IDs!):
http://graph.facebook.com/fql?q=select%20eid%2C%20creator%2C%20name%2C%20description%2C%20start_time%2C%20end_time%2C%20timezone%2C%20location%20from%20event%20where%20creator%20in%20(1234,5678)%20and%20start_time%20%3E%20now()%20order%20by%20creator%20asc
But then you have to restructure your code a little bit, because the result will look like the following:
{
"data": [
{
"eid": 2289962603,
"creator": 1146614804,
"name": "eventname",
"description": "descr",
"start_time": "2014-05-30T21:00:00+0200",
"end_time": null,
"timezone": "Europe/Berlin",
"location": "thelocation"
},
...
]
}
You then have to react on changes of the value for the creator field, which then indicated that there's a new calendar to be created (creator = page_id)