date_repeat_calc.inc in Date 6
Same filename and directory in other branches
Code to compute the dates that match an iCal RRULE.
Moved to a separate file since it is not used on most pages so the code is not parsed unless needed.
Extensive simpletests have been created to test the RRULE calculation results against official examples from RFC 2445.
These calculations are expensive and results should be stored or cached so the calculation code is not called more often than necessary.
Currently implemented: INTERVAL, UNTIL, COUNT, EXDATE, BYDAY, BYMONTHDAY, BYMONTH, YEARLY, MONTHLY, WEEKLY, DAILY
Currently not implemented:
BYYEARDAY, MINUTELY, HOURLY, SECONDLY, BYMINUTE, BYHOUR, BYSECOND These could be implemented in the future.
BYSETPOS Seldom used anywhere, so no reason to complicated the code.
File
date_repeat/date_repeat_calc.incView source
<?php
/**
* @file
* Code to compute the dates that match an iCal RRULE.
*
* Moved to a separate file since it is not used on most pages
* so the code is not parsed unless needed.
*
* Extensive simpletests have been created to test the RRULE calculation
* results against official examples from RFC 2445.
*
* These calculations are expensive and results should be stored or cached
* so the calculation code is not called more often than necessary.
*
* Currently implemented:
* INTERVAL, UNTIL, COUNT, EXDATE, BYDAY, BYMONTHDAY, BYMONTH,
* YEARLY, MONTHLY, WEEKLY, DAILY
*
* Currently not implemented:
*
* BYYEARDAY, MINUTELY, HOURLY, SECONDLY, BYMINUTE, BYHOUR, BYSECOND
* These could be implemented in the future.
*
* BYSETPOS
* Seldom used anywhere, so no reason to complicated the code.
*/
/**
* Private implementation of date_repeat_calc().
*
* Compute dates that match the requested rule, within a specified date range.
*/
function _date_repeat_calc($rrule, $start, $end, $exceptions) {
include_once './' . drupal_get_path('module', 'date_api') . '/date_api_ical.inc';
// TODO, is this the right timezone to use? Generally date calculations
// work best if done in UTC, but need to verify it won't create problems.
$timezone = 'UTC';
// Get the parsed array of rule values.
$rrule = date_ical_parse_rrule('RRULE:', $rrule);
// Create a date object for the start and end dates.
$start_date = date_make_date($start, $timezone);
$end_date = date_make_date($end, $timezone);
// If the rule has an UNTIL, see if that is earlier than the end date.
if ($rrule['UNTIL']) {
$until_date = date_ical_date($rrule['UNTIL']);
if (date_format($until_date, 'U') < date_format($end_date, 'U')) {
$end_date = $until_date;
}
}
// Get an integer value for the interval, if none given, '1' is implied.
$interval = max(1, $rrule['INTERVAL']);
$count = isset($rrule['COUNT']) ? $rrule['COUNT'] : NULL;
// Find the time period to jump forward between dates.
switch ($rrule['FREQ']) {
case 'DAILY':
$jump = $interval . ' days';
break;
case 'WEEKLY':
$jump = $interval . ' weeks';
break;
case 'MONTHLY':
$jump = $interval . ' months';
break;
case 'YEARLY':
$jump = $interval . ' years';
break;
}
$rrule = date_repeat_adjust_rrule($rrule, $start_date);
// The start date always goes into the results, whether or not it meets
// the rules. RFC 2445 includes examples where the start date DOES NOT
// meet the rules, but the expected results always include the start date.
$days = array(
date_format($start_date, DATE_FORMAT_DATETIME),
);
// BYMONTHDAY will look for specific days of the month in one or more months.
// This process is only valid when frequency is monthly or yearly.
if (!empty($rrule['BYMONTHDAY'])) {
if (!in_array($rrule['FREQ'], array(
'MONTHLY',
'YEARLY',
))) {
return $days;
}
$finished = FALSE;
$current_day = drupal_clone($start_date);
$time = date_format($start_date, 'H:i:s');
$direction_days = array();
// Deconstruct the day in case it has a negative modifier.
foreach ($rrule['BYMONTHDAY'] as $day) {
ereg("(-)?([0-9]{1,2})", $day, $regs);
if (!empty($regs[2])) {
// Convert parameters into full day name, count, and direction.
$direction_days[$day] = array(
'direction' => !empty($regs[1]) ? $regs[1] : '+',
'direction_count' => $regs[2],
);
}
}
while (!$finished) {
$period_finished = FALSE;
while (!$period_finished) {
foreach ($rrule['BYMONTHDAY'] as $monthday) {
$day = $direction_days[$monthday];
$current_day = date_repeat_set_month_day($current_day, NULL, $day['direction_count'], $day['direction']);
date_repeat_add_dates($days, $current_day, $start_date, $end_date, $exceptions, $rrule);
if ($finished = date_repeat_is_finished($current_day, $days, $count, $end_date)) {
$period_finished = TRUE;
}
}
// If it's monthly, keep looping through months, one INTERVAL at a time.
if ($rrule['FREQ'] == 'MONTHLY') {
if ($finished = date_repeat_is_finished($current_day, $days, $count, $end_date)) {
$period_finished = TRUE;
}
// Back up to first of month and jump.
$current_day = date_repeat_set_month_day($current_day, NULL, 1);
date_modify($current_day, $jump);
}
else {
if (date_format($current_day, 'n') == 12) {
$period_finished = TRUE;
}
else {
// Back up to first of month and jump.
$current_day = date_repeat_set_month_day($current_day, NULL, 1);
date_modify($current_day, '+1 month');
}
}
}
if ($rrule['FREQ'] == 'YEARLY') {
// Back up to first of year and jump.
$current_day = date_repeat_set_year_day($current_day, NULL, 1);
date_modify($current_day, $jump);
}
$finished = date_repeat_is_finished($current_day, $days, $count, $end_date);
}
}
elseif (!$rrule['BYDAY']) {
// $current_day will keep track of where we are in the calculation.
$current_day = drupal_clone($start_date);
$finished = FALSE;
$months = $rrule['BYMONTH'];
while (!$finished) {
date_repeat_add_dates($days, $current_day, $start_date, $end_date, $exceptions, $rrule);
$finished = date_repeat_is_finished($current_day, $days, $count, $end_date);
date_modify($current_day, $jump);
}
}
else {
// More complex searches for day names and criteria like '-1SU' or '2TU,2TH',
// require that we interate through the whole time period checking each BYDAY.
// Create helper array to pull day names out of iCal day strings.
$day_names = date_repeat_dow_day_options();
$days_of_week = array_keys($day_names);
// Parse out information about the BYDAYs and separate them
// depending on whether they have directional parameters like -1SU or 2TH.
$month_days = array();
$week_days = array();
// Find the right first day of the week to use, iCal rules say Monday
// should be used if none is specified.
$week_start_rule = $rrule['WKST'] ? $rrule['WKST'] : 'MO';
$week_start_day = $day_names[$week_start_rule];
// Make sure the week days array is sorted into week order,
// we use the $ordered_keys to get the right values into the key
// and force the array to that order. Needed later when we
// iterate through each week looking for days so we don't
// jump to the next week when we hit a day out of order.
$ordered = date_repeat_days_ordered($week_start_rule);
$ordered_keys = array_flip($ordered);
foreach ($rrule['BYDAY'] as $day) {
ereg("(-)?([1-5])?([SU|MO|TU|WE|TH|FR|SA]{2})", $day, $regs);
if (!empty($regs[2])) {
// Convert parameters into full day name, count, and direction.
$direction_days[] = array(
'day' => $day_names[$regs[3]],
'direction' => !empty($regs[1]) ? $regs[1] : '+',
'direction_count' => $regs[2],
);
}
else {
$week_days[$ordered_keys[$regs[3]]] = $day_names[$regs[3]];
}
}
ksort($week_days);
// BYDAYs with parameters like -1SU (last Sun) or 2TH (second Thur)
// need to be processed one month or year at a time.
if (!empty($direction_days) && in_array($rrule['FREQ'], array(
'MONTHLY',
'YEARLY',
))) {
$finished = FALSE;
$current_day = drupal_clone($start_date);
while (!$finished) {
foreach ($direction_days as $day) {
// Find the BYDAY date in the current month.
if ($rrule['FREQ'] == 'MONTHLY') {
$current_day = date_repeat_set_month_day($current_day, $day['day'], $day['direction_count'], $day['direction']);
}
else {
$current_day = date_repeat_set_year_day($current_day, $day['day'], $day['direction_count'], $day['direction']);
}
date_repeat_add_dates($days, $current_day, $start_date, $end_date, $exceptions, $rrule);
}
$finished = date_repeat_is_finished($current_day, $days, $count, $end_date);
// Jump to the next period.
date_modify($current_day, '+' . $jump);
}
}
// For BYDAYs without parameters,like TU,TH (every Tues and Thur),
// we look for every one of those days during the frequency period.
// Iterate through periods of a WEEK, MONTH, or YEAR, checking for
// the days of the week that match our criteria for each week in the
// period, then jumping ahead to the next week, month, or year,
// an INTERVAL at a time.
if (!empty($week_days) && in_array($rrule['FREQ'], array(
'MONTHLY',
'WEEKLY',
'YEARLY',
))) {
$finished = FALSE;
$current_day = drupal_clone($start_date);
$format = $rrule['FREQ'] == 'YEARLY' ? 'Y' : 'n';
$current_period = date_format($current_day, $format);
// Back up to the beginning of the week in case we are somewhere in the
// middle of the possible week days, needed so we don't prematurely
// jump to the next week. The date_repeat_add_dates() function will
// keep dates outside the range from getting added.
if (date_repeat_dow2day(date_format($current_day, 'w')) != $week_start_day) {
date_modify($current_day, '-1 ' . $week_start_day);
}
while (!$finished) {
$period_finished = FALSE;
while (!$period_finished) {
foreach ($week_days as $delta => $day) {
// Find the next occurence of each day in this week, only add it
// if we are still in the current month or year. The date_repeat_add_dates
// function is insufficient to test whether to include this date
// if we are using a rule like 'every other month', so we must
// explicitly test it here.
if (date_format($current_day, 'l') != $day) {
date_modify($current_day, '+1 ' . $day);
}
if ($rrule['FREQ'] == 'WEEKLY' || date_format($current_day, $format) == $current_period) {
date_repeat_add_dates($days, $current_day, $start_date, $end_date, $exceptions, $rrule);
}
}
$finished = date_repeat_is_finished($current_day, $days, $count, $end_date);
// If this is a WEEKLY frequency, stop after each week,
// otherwise, stop when we've moved outside the current period.
// Jump to the end of the week, then test the period.
date_modify($current_day, '+1 ' . $week_start_day);
date_modify($current_day, '-1 day');
if ($finished || $rrule['FREQ'] == 'WEEKLY') {
$period_finished = TRUE;
}
elseif ($rrule['FREQ'] != 'WEEKLY' && date_format($current_day, $format) != $current_period) {
$period_finished = TRUE;
}
}
// Go back to the beginning of this period before we jump, to
// ensure we jump to the first day of the next period. We've moved to
// the next month or year, so it takes an extra jump back to get
// back to the first day of the current period.
switch ($rrule['FREQ']) {
case 'WEEKLY':
date_modify($current_day, '+1 ' . $week_start_day);
date_modify($current_day, '-1 week');
break;
case 'MONTHLY':
date_modify($current_day, '-' . (date_format($current_day, 'j') - 1) . ' days');
date_modify($current_day, '-1 month');
break;
case 'YEARLY':
date_modify($current_day, '-' . date_format($current_day, 'z') . ' days');
date_modify($current_day, '-1 year');
break;
}
// Jump ahead to the next period to be evaluated.
date_modify($current_day, '+' . $jump);
$current_period = date_format($current_day, $format);
$finished = date_repeat_is_finished($current_day, $days, $count, $end_date);
}
}
}
sort($days);
return $days;
}
/**
* See if the RRULE needs some imputed values added to it.
*/
function date_repeat_adjust_rrule($rrule, $start_date) {
// RFC 2445 says if no day or monthday is specified when creating repeats for
// weeks, months, or years, impute the value from the start date.
if (empty($rrule['BYDAY']) && $rrule['FREQ'] == 'WEEKLY') {
$rrule['BYDAY'] = array(
date_repeat_dow2day(date_format($start_date, 'w')),
);
}
elseif (empty($rrule['BYDAY']) && empty($rrule['BYMONTHDAY']) && $rrule['FREQ'] == 'MONTHLY') {
$rrule['BYMONTHDAY'] = array(
date_format($start_date, 'j'),
);
}
elseif (empty($rrule['BYDAY']) && empty($rrule['BYMONTHDAY']) && empty($rrule['BYYEARDAY']) && $rrule['FREQ'] == 'YEARLY') {
$rrule['BYMONTHDAY'] = array(
date_format($start_date, 'j'),
);
if (empty($rrule['BYMONTH'])) {
$rrule['BYMONTH'] = array(
date_format($start_date, 'n'),
);
}
}
elseif (!empty($rrule['BYDAY']) && !in_array($rrule['FREQ'], array(
'MONTHLY',
'YEARLY',
))) {
foreach ($rrule['BYDAY'] as $delta => $BYDAY) {
$rrule['BYDAY'][$delta] = substr($BYDAY, -2);
}
}
return $rrule;
}
/**
* Helper function to add found date to the $dates array.
*
* Check that the date to be added is between the start and end date
* and that it is not in the $exceptions, nor already in the $days array,
* and that it meets other criteria in the RRULE.
*/
function date_repeat_add_dates(&$days, $current_day, $start_date, $end_date, $exceptions, $rrule) {
if (isset($rrule['COUNT']) && sizeof($days) >= $rrule['COUNT']) {
return FALSE;
}
$formatted = date_format($current_day, DATE_FORMAT_DATETIME);
if ($formatted > date_format($end_date, DATE_FORMAT_DATETIME)) {
return FALSE;
}
if ($formatted < date_format($start_date, DATE_FORMAT_DATETIME)) {
return FALSE;
}
if (in_array(date_format($current_day, 'Y-m-d'), $exceptions)) {
return FALSE;
}
if (!empty($rrule['BYDAY'])) {
$BYDAYS = $rrule['BYDAY'];
foreach ($BYDAYS as $delta => $BYDAY) {
$BYDAYS[$delta] = substr($BYDAY, -2);
}
if (!in_array(date_repeat_dow2day(date_format($current_day, 'w')), $BYDAYS)) {
return FALSE;
}
}
if (!empty($rrule['BYYEAR']) && !in_array(date_format($current_day, 'Y'), $rrule['BYYEAR'])) {
return FALSE;
}
if (!empty($rrule['BYMONTH']) && !in_array(date_format($current_day, 'n'), $rrule['BYMONTH'])) {
return FALSE;
}
if (!empty($rrule['BYMONTHDAY'])) {
// Test month days, but only if there are no negative numbers.
$BYMONTHDAYS = array();
foreach ($rrule['BYMONTHDAY'] as $day) {
if ($day > 0) {
$BYMONTHDAYS[] = $day;
}
else {
break;
}
}
if (!empty($BYMONTHDAYS) && !in_array(date_format($current_day, 'j'), $BYMONTHDAYS)) {
return FALSE;
}
}
// Don't add a day if it is already saved so we don't throw the count off.
if (in_array($formatted, $days)) {
return TRUE;
}
else {
$days[] = $formatted;
}
}
/**
* Stop when $current_day is greater than $end_date or $count is reached.
*/
function date_repeat_is_finished($current_day, $days, $count, $end_date) {
if ($count && sizeof($days) >= $count || date_format($current_day, 'U') > date_format($end_date, 'U')) {
return TRUE;
}
else {
return FALSE;
}
}
/**
* Set a date object to a specific day of the month.
*
* Example,
* date_set_month_day($date, 'Sunday', 2, '-')
* will reset $date to the second to last Sunday in the month.
* If $day is empty, will set to the number of days from the
* beginning or end of the month.
*/
function date_repeat_set_month_day($date_in, $day, $count = 1, $direction = '+') {
if (is_object($date_in)) {
// Reset to the start of the month.
// We should be able to do this with date_date_set(), but
// for some reason the date occasionally gets confused if run
// through this function multiple times. It seems to work
// reliably if we create a new object each time.
$datetime = date_format($date_in, DATE_FORMAT_DATETIME);
$datetime = substr_replace($datetime, '01', 8, 2);
$date = date_make_date($datetime, 'UTC');
if ($direction == '-') {
// For negative search, start from the end of the month.
date_modify($date, '+1 month');
}
else {
// For positive search, back up one day to get outside the
// current month, so we can catch the first of the month.
date_modify($date, '-1 day');
}
if (empty($day)) {
$day = 'days';
}
date_modify($date, $direction . $count . ' ' . $day);
}
return $date;
}
/**
* Set a date object to a specific day of the year.
*
* Example,
* date_set_year_day($date, 'Sunday', 2, '-')
* will reset $date to the second to last Sunday in the year.
* If $day is empty, will set to the number of days from the
* beginning or end of the year.
*/
function date_repeat_set_year_day($date_in, $day, $count = 1, $direction = '+') {
if (is_object($date_in)) {
// Reset to the start of the month.
// See note above.
$datetime = date_format($date_in, DATE_FORMAT_DATETIME);
$datetime = substr_replace($datetime, '01-01', 5, 5);
$date = date_make_date($datetime, 'UTC');
if ($direction == '-') {
// For negative search, start from the end of the year.
date_modify($date, '+1 year');
}
else {
// For positive search, back up one day to get outside the
// current year, so we can catch the first of the year.
date_modify($date, '-1 day');
}
if (empty($day)) {
$day = 'days';
}
date_modify($date, $direction . $count . ' ' . $day);
}
return $date;
}Functions
Name |
Description |
|---|---|
| date_repeat_add_dates | Helper function to add found date to the $dates array. |
| date_repeat_adjust_rrule | See if the RRULE needs some imputed values added to it. |
| date_repeat_is_finished | Stop when $current_day is greater than $end_date or $count is reached. |
| date_repeat_set_month_day | Set a date object to a specific day of the month. |
| date_repeat_set_year_day | Set a date object to a specific day of the year. |
| _date_repeat_calc | Private implementation of date_repeat_calc(). |