1 files changed, 138 insertions, 0 deletions
diff --git a/ical-feed.php b/ical-feed.php
new file mode 100644
index 0000000..ee1eeba
--- /dev/null
+++ b/ical-feed.php
@@ -0,0 +1,138 @@
+<?php
+/* DISPLAY - iCal export
+ *
+ */
+
+function communievents_escape_ical_text($text) {
+    return strtr($text, array(
+        "\\" => "\\\\",
+        ',' => '\,',
+        ';' => '\;',
+        "\r\n" => "\\n", // spec says line breaks need to be \n only
+        "\n" => "\\n"
+    ));
+}
+
+// FIXME! this assumes valid utf-8
+function communievents_fold_ical_line_helper($text, $index, $maxlength) {
+    $length = 0;
+    $i = $index;
+
+    while ($i < strlen($text) && $length < $maxlength) {
+        $c = ord($text[$i]);
+        if ($c < 128) {
+            $clen = 1;
+        } else if ($c < 224) {
+            $clen = 2;
+        } else if ($c < 240) {
+            $clen = 3;
+        } else {
+            $clen = 4;
+        }
+
+        if ($length + $clen > $maxlength)
+            break;
+
+        $i += $clen;
+        $length += $clen;
+    }
+
+    return substr($text, $index, $length);
+}
+
+function communievents_fold_ical_text($text) {
+    //XXX: the iCal spec wants the lines to be at most 75 octets,
+    // but we must not split UTF-8 because some readers (notably
+    // thunderbird) choke on it, even though the RFC says you
+    // should handle it gracefully :-(
+
+    if (strlen($text) <= 75) {
+        return $text;
+    } else {
+        $text_arr = array();
+        $text_arr[0] = communievents_fold_ical_line_helper($text, 0, 75);
+        $i = strlen($text_arr[0]);
+        while ($i < strlen($text)) {
+            $s = communievents_fold_ical_line_helper($text, $i, 74);
+            $i += strlen($s);
+            $text_arr[] = $s;
+        }
+
+        return join("\r\n ", $text_arr);
+    }
+}
+
+function communievents_write_ical_line($field, $text) {
+    echo communievents_fold_ical_text("$field:" . communievents_escape_ical_text($text)) . "\r\n";
+}
+
+function communievents_print_ical_feed() {
+    global $wpdb;
+
+    $tz      = new DateTimeZone(CommuniApi::TIMEZONE);
+    $tz_utc  = new DateTimeZone('UTC');
+    $now_utc = new DateTime('now', $tz_utc);
+    $dtstamp = $now_utc->format('Ymd\THis\Z');
+
+    header('Content-Type: text/calendar');
+    header('Content-Disposition: attachment; filename="communievents.ics"');
+
+    communievents_write_ical_line('BEGIN', 'VCALENDAR');
+    communievents_write_ical_line('VERSION', '2.0');
+    communievents_write_ical_line('PRODID', '-//' . get_bloginfo('name') . '//NONSGML Events//EN');
+    communievents_write_ical_line('CALSCALE', 'GREGORIAN');
+    communievents_write_ical_line('X-WR-TIMEZONE', CommuniApi::TIMEZONE);
+
+    $table_name = $wpdb->prefix . 'communievents_events';
+
+    $list = $wpdb->get_results("SELECT * FROM $table_name WHERE official=1 ORDER BY start");
+
+    if ($list) {
+        foreach ($list as $event) {
+            $start_dt = new DateTime($event->start, $tz);
+            $end_dt = new DateTime($event->end, $tz);
+
+            communievents_write_ical_line('BEGIN', 'VEVENT');
+
+            communievents_write_ical_line('UID', 'communi-event-' . $event->id . '-' . $start_dt->format('U'));
+            communievents_write_ical_line('STATUS', 'CONFIRMED');
+            communievents_write_ical_line('DTSTAMP', $dtstamp);
+            if ($event->allday) {
+                communievents_write_ical_line('DTSTART;VALUE=DATE', $start_dt->format('Ymd'));
+                if ($end_dt->format('Ymd') != $start_dt->format('Ymd')) {
+                    // end is non-inclusive! move it into the next day
+                    $end_dt->modify('+1 minute');
+                    communievents_write_ical_line('DTEND;VALUE=DATE', $end_dt->format('Ymd'));
+                }
+            } else {
+                communievents_write_ical_line('DTSTART', $start_dt->format('Ymd\THis'));
+                if ($event->end != $event->start) {
+                    communievents_write_ical_line('DTEND', $end_dt->format('Ymd\THis'));
+                }
+            }
+
+            communievents_write_ical_line('SUMMARY', $event->title);
+
+            if (!empty($event->description)) {
+                communievents_write_ical_line('DESCRIPTION', html_entity_decode(strip_tags($event->description), ENT_QUOTES|ENT_SUBSTITUTE|ENT_HTML5, 'UTF-8'));
+                communievents_write_ical_line('X-ALT-DESC;FMTTYPE=text/html', $event->description);
+            }
+
+            if (!empty($event->location)) {
+                communievents_write_ical_line('LOCATION', $event->location);
+            }
+
+            communievents_write_ical_line('URL;VALUE=URI', $event->url);
+
+            communievents_write_ical_line('END', 'VEVENT');
+        }
+    }
+
+    communievents_write_ical_line('END', 'VCALENDAR');
+}
+
+function communievents_setup_ical_feed() {
+   add_feed('communievents-ics', 'communievents_print_ical_feed');
+   // FIXME: emklahr.de compat HACK
+   add_feed('eo-events', 'communievents_print_ical_feed');
+}