big changes to recurrence; trying to get closer to the spec

1 files changed, 111 insertions, 0 deletions

diff --git a/functions/parse/recur_functions.php b/functions/parse/recur_functions.php
new file mode 100644
index 0000000..5b845b3
--- /dev/null
+++ b/functions/parse/recur_functions.php
@@ -0,0 +1,111 @@
+<?php
+
+/* from the std
+
+BYxxx rule parts modify the recurrence in some manner. BYxxx rule
+   parts for a period of time which is the same or greater than the
+   frequency generally reduce or limit the number of occurrences of the
+   recurrence generated. For example, "FREQ=DAILY;BYMONTH=1" reduces the
+   number of recurrence instances from all days (if BYMONTH tag is not
+   present) to all days in January. BYxxx rule parts for a period of
+   time less than the frequency generally increase or expand the number
+   of occurrences of the recurrence. For example,
+   "FREQ=YEARLY;BYMONTH=1,2" increases the number of days within the
+   yearly recurrence set from 1 (if BYMONTH tag is not present) to 2.
+
+   If multiple BYxxx rule parts are specified, then after evaluating the
+   specified FREQ and INTERVAL rule parts, the BYxxx rule parts are
+   applied to the current set of evaluated occurrences in the following
+   order: BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY, BYDAY, BYHOUR,
+   BYMINUTE, BYSECOND and BYSETPOS; then COUNT and UNTIL are evaluated.
+
+	We will use two kinds of functions - those that restrict the date to allowed values and those that expand allowed values
+
+*/
+
+function add_recur($times,$freq=''){
+	global $recur_data;	
+	if (!is_array($times)) $times = array($times);
+	/*BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY, BYDAY, BYHOUR,
+   BYMINUTE, BYSECOND and BYSETPOS*/
+	$times = restrict_bymonth($times,$freq); 
+	$times = restrict_byweekno($times,$freq);
+	$times = restrict_byyearday($times,$freq);
+	$times = restrict_bymonthday($times,$freq);
+	$times = restrict_byday($times,$freq);
+	$times = restrict_bysetpos($times,$freq);
+
+	foreach ($times as $time) if(isset($time)) $recur_data[] = $time;
+	return;
+}
+
+function expand_byday($time){
+	global $freq_type, $byday, $wkst3char;
+	$the_sunday = dateOfWeek(date("Ymd",$time), $wkst3char);
+#	echo "$freq_type, ".print_r($byday,true)."$wkst3char $the_sunday";
+	if (empty($byday)) $byday[] = strtoupper(substr(date('D', $time), 0, 2));					
+	foreach($byday as $key=>$day) {
+		/* set $byday_arr
+				[0] => byday string, e.g. 4TH
+				[1] => sign/modifier
+				[2] => 4 number
+				[3] => TH day abbr
+		*/
+		ereg ('([-\+]{0,1})?([0-9]{1})?([A-Z]{2})', $day, $byday_arr);
+		$on_day = two2threeCharDays($byday_arr[3]);
+		switch($freq_type){
+			case 'week':
+				#need to find the first day of the appropriate week.						
+				if ($key == 0){ 
+					$next_date_time = strtotime("next $on_day",strtotime($the_sunday)) + (12 * 60 * 60);
+				}else{
+					$next_date_time = strtotime("next $on_day",$next_date_time) + (12 * 60 * 60);						
+				}
+			default:	
+				$next_date_time = strtotime($byday_arr[1].$byday_arr[2].$on_day, $time); 
+		}
+		$times[] = $next_date_time; 
+	}
+	return $times;
+}
+
+
+function restrict_bymonth($times,$freq=''){
+	global $bymonth;
+	if (empty($bymonth)) return $times;
+	foreach ($times as $time) if(in_array(date("m", $time), $bymonth)) $new_times[] = $time;
+	return $new_times;
+}
+function restrict_byweekno($times,$freq=''){
+	global $byweekno;
+	if(empty($byweekno)) return $times;
+	foreach ($times as $time) if(in_array(date("W", $time), $byweekno)) $new_times[] = $time;
+	return $new_times;
+
+}
+function restrict_byyearday($times,$freq=''){
+	global $byyearday;
+	if(empty($byyearday)) return $times;
+	foreach ($times as $time) if(in_array(date("z", $time), $byyearday)) $new_times[] = $time;
+	return $new_times;
+}
+
+function restrict_bymonthday($times,$freq=''){
+	global $bymonthday;
+	if(empty($bymonthday)) return $times;
+	foreach ($times as $time) if(in_array(date("j", $time), $bymonthday)) $new_times[] = $time;
+	return $new_times;
+}
+function restrict_byday($times,$freq=''){
+	global $byday;
+	if(empty($byday)) return $times;
+	foreach($byday as $key=>$day) $byday3[] = two2threeCharDays($day);	
+	foreach ($times as $time) if(in_array(strtolower(date("D", $time)), $byday3)) $new_times[] = $time;
+	return $new_times;	
+}
+
+function restrict_bysetpos($times,$freq=''){
+	global $rrule_array, $bysetpos;
+	if(empty($bysetpos)) return $times;
+
+}
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