modules/eventrepeat/eventrepeat.module

<?php
// $Id: eventrepeat.module,v 1.64 2009/05/10 00:03:05 rmiddle Exp $

// TODO: Update this section

//KNOWN BUGS
//this module is currently in beta release.  known bugs include:
//  1. exception editor not working
//  2. editing the repeat sequence itself after it's already been created is inconsistent.  nodes don't map to the exact
//     date they're being moved to
//  3. bug: items getting rendered on day previous to creation day

//TODO
//  1. put form_set_error in place of drupal_set_message where appropriate.  change drupal_set_message to warning
//     where appropriate
//  2. add watchdog entries


//  WISH LIST
//  1. invoke hook 'delete pre' for multi deletions (single node only?)
//  2. add ical support

//include_once(drupal_get_path('module', 'event') .'/event_timezones.inc');
include(drupal_get_path('module', 'eventrepeat') .'/eventrepeat.theme');

/**
 * @file
 *
 * Event Repeats and repeating events to the event module.
 */

/**
 * @defgroup eventrepeat_core Core drupal hooks
 */

/**
 * Implementation of hook_cron().
 *
 * @ingroup eventrepeat_core
 */
function eventrepeat_cron() {

  //this value determines the maximum number of rows that can be added to the calmap table in one cron run, and should be
  //set to a reasonable value to avoid server timeouts that could occur. this will most likely only happen when initially
  //seeding the table.  default value is 2000 rows
  $_BAILOUT_VALUE = variable_get('eventrepeat_maximum_rows', 2000);

  //the table values for eventrepeat_calmap
  //day_stamp: human readable date in the format Y-m-d.  also used in SQL queries
  //date_stamp: date for which the RRULE values are being generated, timestamp is last second of the day, in UTC
  //day_of_week: day of the week in the following format 'SU', 'MO', 'TU', 'WE', 'TH', 'FR', 'SA'
  //day_in_month: iteration of the day of the week in the month in the following format '1SU', '3MO'
  //day_in_month_R: iteration of the day of the week in the month, counting from the end, in the following format '-1SU', '-3MO'
  //month_day: numeric day of the month in the following format '1', '15'
  //month_day_R: numeric day of the month, counting from the end, in the following format '-1', '-15'
  //month: numeric month number, in the following format '1', '12'
  //year_day: numeric day of the year in the following format '1', '226'
  //year_day_R: numeric day of the year, counting from the end, in the following format '-1', '-226'
  //week_number: numeric ISO-8601 week in the following format '1', '24'
  //week_number_R: numeric ISO-8601 week, counting from the end, in the following format '-1', '-24'

  //first thing is to determine the exact range that's going to be rendered, and calculate start and end timestamps.
  //current time is calculated in GMT, then we check the table for the last created date.  if no records are in the
  //table, set start date to the end of the day on the day before the current date, and enable the seed.
  $curtime = time();
  $result = db_query("SELECT MAX(date_stamp) FROM {eventrepeat_calendar_map}");
  $start = db_fetch_array($result);
  if ($start['MAX(date_stamp)']) {
    $start = $start['MAX(date_stamp)'];
  }
  else {
    $start = gmmktime(23, 59, 59, (int) gmdate('n', $curtime), (int) gmdate('j', $curtime), (int) gmdate('Y', $curtime)) - 86400;
    $seed = TRUE;
  }

  //end date is the current day, plus one day, plus the render support period
  $curtime_end = gmmktime(23, 59, 59, (int) gmdate('n', $curtime), (int) gmdate('j', $curtime), (int) gmdate('Y', $curtime));
  $end = $curtime_end + 86400 + (variable_get('eventrepeat_render_support', 2000) * 86400);

  //next, we want to delete any table entries that are no longer needed.  leave yesterday's date in as a precaution.
  //since cron will probably be run more than once a day, and it's also possible that the admin may have shortened the
  //render period since the last cron run, we put in a few checks for that, too, and exit the function if it doesn't
  //need to be run now
  if ($end < $start) {
    db_query('DELETE FROM {eventrepeat_calendar_map} WHERE date_stamp > %d', $end);
    return;
  }

  $result = db_query('SELECT date_stamp FROM {eventrepeat_calendar_map} WHERE date_stamp < %d', $curtime - 86400);
  if (db_result($result) > 0 || $seed) {
    $result = db_query('DELETE FROM {eventrepeat_calendar_map} WHERE date_stamp < %d', $curtime - 86400);
  }
  else {
    return;
  }

  //set the insert query line, initialize the array where we'll dump the values initially, and start a bailout counter:
  //this counter will count up and bail out of the calmap cycle when it hits _BAIL_OUT_VALUE, which can be set at the top
  //of the function
  $insert_line = "INSERT INTO {eventrepeat_calendar_map} (day_stamp, date_stamp, day_of_week, day_in_month,
    day_in_month_R, month_day ,month_day_R, month, year_day, year_day_R, week_number, week_number_R)  VALUES";
  $values = array();
  $bailout = 1;

  //create timestamp for first day of the month which $start is in.  this is the easiest way to count to generate info
  //for the date range that needs to be rendered.  also create the other initial calendar values we'll need here, based
  //on the beginning of the month timestamp
  $BOM = gmmktime(23, 59, 59, (int) gmdate('n', $start), 1, (int) gmdate('Y', $start));
  $master_year = (int) gmdate('Y', $BOM);    //current year
  $leap_year = (int) gmdate('L', $BOM);      //Whether it's a leap year
  $days_in_month = (int) gmdate('t', $BOM);  //Number of days in the given month
  $days_of_week = array('SU', 'MO', 'TU', 'WE', 'TH', 'FR', 'SA');
  $master_month = (int) gmdate('n', $BOM);     //current month
  $master_month_day = 1;   //current numeric day of the month
  $master_month_day_R = -$days_in_month;  //current numeric day of the month, counting backwards
  $master_day = (int) gmdate('w', $BOM);    //day of the week of the first day of the month, for incrementing day counts
  $master_last_day = (int) gmdate('w', gmmktime(23, 59, 59, (int) gmdate('n', $start), $days_in_month,
    (int) gmdate('Y', $start)));
  $dow = $master_day;   //current day of the week

  //1st day of the month will always be the first of it's kind with respect to the day of the week, so we set that
  //to one here.  months will have certain days of the week that occur 4 times, and others that occur 5 times, so
  //here we also build an incrementer that will help with correct reverse day in month calculations
  $master_day_in_month = 1;
  $master_day_in_month_R = -4;
  $day_in_month_incrementer = _eventrepeat_day_in_month_incrementer($master_day, $days_in_month);

  $master_year_day = (int) gmdate('z', $BOM) + 1;    //current numeric day of the year
  $master_year_day_R = $master_year_day - 365 - $leap_year - 1;   //current numeric day of the year, counting backwards
  $master_week_no = (int) gmdate('W', $BOM);  //generate the ISO-8601 week no.

  //figure out how many ISO-8601 weeks are in the current year.  this seems like a hack but i wasn't sure how
  //else to do it w/ php's date function
  for ($n = 28; $n <= 31; $n++) {
    $WN_stamp = gmmktime(23, 59, 59, 12, $n, $master_year);
    $master_weeks_in_year = (int) gmdate('W', $WN_stamp) > $master_weeks_in_year ? (int) gmdate('W', $WN_stamp) :
      $master_weeks_in_year;
    }
    $master_week_no_R = $master_week_no - $master_weeks_in_year - 1;   //ISO-8601 week no. in year counting backwards

  //now we move from the beginning of the month to the day before the start of the rendering period, adjusting values
  //for everything we set above as we go.  set the counter that increments by one day, and if the start of the rendering
  //cycle is the beginning of the month, skip this step
  $counter = $BOM + 86400;
  if ($BOM != $start) {
    while ($counter <= $start) {

      //cycle through the numeric days of the week
      if ($dow == 6) {
        $dow = 0;
      }
      else {
        $dow++;
      }

      //each time we get back around to the day of the week of the first day of the month, we increment the
      //master_day_in_month counters
      if ($master_day == $dow) {
        $master_day_in_month++;
        $master_day_in_month_R++;
      }

      //increment the master_month_day and master_year_day counters
      $master_month_day++;
      $master_month_day_R++;
      $master_year_day++;
      $master_year_day_R++;

      //increment the weekno. variables if the day of the week is monday
      if ($dow == 1) {
        $master_week_no++;
        $master_week_no_R++;
      }
      $counter += 86400;
    }
  }

  //now we start the cycle for days where values need to be created
  while ($counter <= $end) {

    //cycle through the numeric days of the week
    if ($dow == 6) {
      $dow = 0;
    }
    else {
      $dow++;
    }

    //each time we get back around to the day of the week of the first day of the month, we increment the
    //master_day_in_month counters
      if ($master_day == $dow) {
      $master_day_in_month++;
      $master_day_in_month_R++;
    }

    //increment the master_month_day and master_year_day counters
    $master_month_day++;
    $master_month_day_R++;
    $master_year_day++;
    $master_year_day_R++;

    //january 4th is the first day of the year that's guaranteed to be in the first ISO-8601 week of the year
    //so here we check to see if it's the 4th and reset the week no. variables if so
    if ($master_month == 1 && $master_month_day == 4) {
      $master_week_no = 1;

      //figure out how many ISO-8601 weeks are in the current year.  this seems like a hack but i wasn't sure how
      //else to do it w/ php's date function.  here also we need to set $master_weeks_in_year back to 52 so the
      //hack will work
      for ($n = 28; $n <= 31; $n++) {
        $master_weeks_in_year = 52;
        $WN_stamp = gmmktime(23, 59, 59, 12, $n, $master_year);
        $master_weeks_in_year = (int) gmdate('W', $WN_stamp) > $master_weeks_in_year ? (int) gmdate('W', $WN_stamp) :
          $master_weeks_in_year;
      }

      $master_week_no_R = $master_week_no - $master_weeks_in_year - 1;   //ISO-8601 week no. in year counting backwards

    //it's not the 4th of january, so increment the weekno. variables if the day of the week is monday
    }
    else {
      if ($dow == 1) {
        $master_week_no++;
        $master_week_no_R++;
      }
    }

    //if the date is between december 28th and january 4th, then we need to manually calculate the weekno.
    //variables, b/c days in this range can fall into either the last week of the year, or the first week
    //of the next year, depending upon which year it is.
    if (($master_month == 12 && $master_month_day > 28) || ($master_month == 1 && $master_month_day < 4)) {
      $master_week_no = (int) gmdate('W', $counter);  //generate the ISO-8601 week no.

      //if the weekno value calculates to 1, then the day is in week of the year we're changing to.  if it's
      //still december then push the temp year forward by one to ensure accurate calculation of the total
      //number of weeks in this new year.  don't forget to set $master_weeks_in_year to 52 again!
      if ($master_week_no == 1) {
        if ($master_month == 12) {
          $master_year_temp = $master_year +1;
        }
        else {
          $master_year_temp = $master_year;
        }
        for ($n = 28; $n <= 31; $n++) {
          $master_weeks_in_year = 52;
          $WN_stamp = gmmktime(23, 59, 59, 12, $n, $master_year_temp);
          $master_weeks_in_year = (int) gmdate('W', $WN_stamp) > $master_weeks_in_year ? (int) gmdate('W', $WN_stamp) :
            $master_weeks_in_year;
        }
      }
      $master_week_no_R = $master_week_no - $master_weeks_in_year - 1;   //ISO-8601 week no. in year counting backwards
    }

    //make day of the week the custom string value, and adjust the reverse day in month value according to the current
    //month's incrementer array
    $day_of_the_week = $days_of_week[$dow];
    $day_of_the_month_R = $master_day_in_month_R - $day_in_month_incrementer[$dow];
    $day_stamp = gmdate('Y-m-d', $counter);

    //populate a new element of the values array with the RRULE data for the day in question
    $values[] = "('$day_stamp', $counter,'$day_of_the_week','". $master_day_in_month.$day_of_the_week ."','".
    $day_of_the_month_R.$day_of_the_week."','".$master_month_day."','".$master_month_day_R."','".
    $master_month ."','". $master_year_day."','". $master_year_day_R."','".$master_week_no."','". $master_week_no_R."')";

    //increment the bailout counter, and check to see if it's at 500.  if so
    //then send the query and bail out
    $bailout++;
    if ($bailout > $_BAILOUT_VALUE) {
      //$result = db_query($insert_line.implode(',', $values));
      foreach ($values as $v) {
        db_query($insert_line . $v);
      }
      return;
    }
    $counter += 86400;

    //here we start checks to see if we're at the end of the current month--if it's december then increment the
    //year counter and reset leap year, and set the month values for january (we need to set the month day values
    //one less than they actually are, b/c they'll be incremented when the code swings around)
    if ($days_in_month == $master_month_day) {
      if ($master_month == 12) {
        $master_year++;
        $leap_year = (int) gmdate('L', $counter);
        $days_in_month = 31;
        $master_month = 1;
        $master_month_day = 0;
        $master_month_day_R = -32;

        //set master day as the next day of the week in the cycle--this is the day of the week of the first
        //day in january
        if ($dow == 6) {
          $master_day = 0;
        }
        else {
          $master_day = $dow + 1;
        }

        //set these 1 less than they need to be here, b/c they'll be incremented to their correct value on next
        //cycle through
        $master_day_in_month = 0;
        $master_day_in_month_R = -5;
        $day_in_month_incrementer = _eventrepeat_day_in_month_incrementer($master_day, $days_in_month);
        $master_year_day = 0;
        $master_year_day_R = -366 - $leap_year;

      //it's not december, so increment the month value, and set the new days in month and month day values
      //once again the month day values need to be one less than their actual value
      }
      else {
        $days_in_month = (int) gmdate('t', $counter);
        $master_month++;
        $master_month_day = 0;
        $master_month_day_R = -$days_in_month -1;

        //set master day as the next day of the week in the cycle--this is the day of the week of the first
        //day of the next month
        if ($dow == 6) {
          $master_day = 0;
        }
        else {
          $master_day = $dow + 1;
        }

        //set these 1 less than they need to be here, b/c they'll be incremented to their correct value on next
        //cycle through, and reset the incrementer for the new month
        $master_day_in_month = 0;
        $master_day_in_month_R = -5;
        $day_in_month_incrementer = _eventrepeat_day_in_month_incrementer($master_day, $days_in_month);
      }
    }
  }

  //we didn't bail out, so insert the new rows into the table, if there any rows to insert
  if (count($values)) {
    //$result = db_query($insert_line.implode(',', $values));
    foreach ($values as $v) {
      db_query($insert_line . $v);
    }
  }

  //we've added new data to the calmap table, so render nodes for all repeat sequences
  $endtime = $curtime + (variable_get('eventrepeat_initial_render', 90) * 86400);
  _eventrepeat_render_nodes('all', $endtime, FALSE, FALSE, FALSE);
}

/**
 * Implementation of form API hook_elements()
 */
function eventrepeat_elements() {
  $type['eventrepeat_date'] = array('#input' => TRUE, );
  return $type;
}

/**
 * Implementation of hook_form_alter().
 *
 * @ingroup eventrepeat_core
 * @param $form_id The form being altered.
 * @param $form The form array.
 */
function eventrepeat_form_alter(&$form, $form_state, $form_id) {

  //check here to see if the node is part of a repeat sequence
  if ($form_id == 'node_delete_confirm') {
    $node = node_load($form['nid']['#value']);
    if ($node->eventrepeat_rid) {

      //create the option array
      $options = array(
        'this' => t('This occurrence only'),
        'future' => t('This occurrence and all future occurrences'),
        'all' => t('All occurrences')
      );

      //construct the radio buttons.  NOTE: in order to prevent name collisions in the admin
      //delete process for multiple nodes, these form elements are named in array fashion, with nid to distinguish
      //the elements of the array
      $form['eventrepeat_delete_type']['#tree'] = TRUE;
      $form['eventrepeat_delete_type']['#weight'] = -12;
      $form['eventrepeat_delete_type'][$node->nid] = array(
        '#type' => 'radios',
        '#title' => t('Repeat event--delete the following'),
        '#default_value' => variable_get('eventrepeat_default_edit_type', 'future'),
        '#options' => $options,
        '#description' => t('\'This occurrence and all future occurrences\' will delete repeat events from the date of the selected node forward, \'All occurrences\' will delete repeat events after today\'s date.'),

      );
    }
  }

  //inject node type settings checkbox for repeat events
  elseif ($form_id == 'node_type_form') {
    $node_type = $form['old_type']['#value'];
    $form['workflow']["eventrepeat_nodeapi"] = array(
      '#type' => 'checkbox',
      '#title' => t('Allow repeat events'),
      '#default_value' => variable_get("eventrepeat_nodeapi_$node_type", FALSE),
      '#description' => t('If selected, users will be allowed to add repeating events for this node type'),
    );
  }

  //inject the appropriate repeat data into the node form if the node type is repeat enabled
  elseif ($form['type']['#value'] .'_node_form' == $form_id) {
    if (variable_get('event_nodeapi_'. $form['type']['#value'], 'never') != 'never' &&
      variable_get('eventrepeat_nodeapi_'. $form['type']['#value'], 0) == 1) {

      //get the node info from the db if not in edit (remember the edit means we are previewing, usually)
      if (isset($_POST['edit']) && (!empty($_POST['edit']))) {
        $edit = $_POST['edit'];
        $node = (object) $edit;
      }
      elseif (isset($form['nid']['#value'])) {
        $node = node_load($form['nid']['#value']);
      }

      // If this is a new node and this user
      // doesn't have access to create repeating events
      // just return.
      if (!$node->nid && !user_access('create repeat events')) {
        return;
      }
      // If, however, this is an existing event that has
      // a repeating pattern attached to it, we need to
      // show the form because otherwise the user would
      // end up breaking this node out of the repeat.
      else if ($node->nid && (!$node->eventrepeat_rid && !user_access('create repeat events')) ) {
        return;
      }

      // TODO: I'm not sure if this is in the right spot, but this seems to be the only reliable place to put it right now
      // adds a new exception to the list if needed
      _eventrepeat_form_add_exception($node);

      // add the repeat pattern form elements
      $form += theme('eventrepeat_form', $node);

    }
  }

  /* this is a check for module dependencies.  the only way we
    can ensure this check happening when the module is initially
    enabled is to insert the check for when the form is initially
    built, which will also be caught when the admin/module page is
    reloaded upon submission.  this means we never want to call this
    function when the form has been submitted, so make sure there's
    no $_POST. */
  elseif ($form_id == 'system_modules' && !$_POST) {
      _eventrepeat_system_module_validate($form);
  }
}

/**
 * Implementation of hook_help().
 *
 * @ingroup eventrepeat_core
 * @param $section The page which is requesting help.
 * @return The help text.
 */
function eventrepeat_help($path, $arg) {
  switch ($path) {
    // General help page
    case 'admin/help#eventrepeat':
      $output = '';
      $output .= t('<p>Eventrepeat enables the creation of repeating event patterns for node types that are event-enabled. In order for repeating events to be created for a node type, you must first configure that node type to be enabled for repeating events. This is done from the <a href="!content_types">content types configuration page</a>. While you\'re in the configuration screen, check that the node type is also able to be viewed in the event calendar.</p>', array('!content_types' => url('admin/content/types')));
      $output .= _eventrepeat_user_help_content(TRUE);
      $output .= t('<p>Eventrepeat\'s pattern creation was largely modeled on the iCal RRULE specification. At this time, it should support all RRULE parameters, with the following exceptions:</p>');
      $output .= t('<ol><li>Recurrance periods less than DAILY</li><li>BYDAY declarations greater than 5 and less than -5 (ex. 20th Monday of the year is not supported).Other similar patterns can be built that should approximate this functionality.</li>   <li>BYSETPOS parameter</li><li>EXRULE parameter</li></ol>');
      return $output;

    // Settings page help
    case 'admin/settings/eventrepeat':
      return t('<p>Adjust how events repeat using the form below. To add the event repeat form to node forms, visit the <a href="!settings">content types page</a>.</p>', array('!settings' => url('admin/content/types')));
  }
}

/**
 * Implementation of hook_menu().
 *
 * @ingroup eventrepeat_core
 * @param $may_cache A boolean indicating whether cacheable menu items should be returned.
 * @return An array of menu items. Each menu item is an associative array.
 */
function eventrepeat_menu() {

  $items['admin/settings/eventrepeat'] = array(
    'title' => 'Repeating Events',
    'description' => 'Change how repeating events are handled.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('eventrepeat_admin_settings'),
    'access arguments' => array('administer site configuration'),
    'type' => MENU_NORMAL_ITEM, // optional
    'weight' => 0
  );
  $items['admin/settings/eventrepeat/debug'] = array(
    'title' => 'Debug',
    'description' => 'Debug repeating events by seeing all patterns at a glance.',
    'page callback' => 'eventrepeat_debug',
    'access arguments' => array('administer site configuration'),
    'weight' => 0
    );
  $items['admin/settings/eventrepeat/reset'] = array(
    'title' => 'Reset',
    'description' => 'Reset the event repeat map.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('eventrepeat_refresh_calendar_map'),
    'access arguments' => array('administer site configuration'),
    'weight' => 1
  );
  $items['eventrepeat/help'] = array(
    'title' => 'How to create repeating events',
    'description' => 'How to create repeating events.',
    'page callback' => 'eventrepeat_user_help_page',
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Implementation of hook_perm().
 * @ingroup eventrepeat_core
 */
function eventrepeat_perm() {
  return array('create repeat events');
}

/**
 * @defgroup eventrepeat_nodeapi Functions for nodeapi integration
 */

/**
 * hook_nodeapi implementation
 *
 * @ingroup eventrepeat_nodeapi
 * @param &$node The node the action is being performed on.
 * @param $op What kind of action is being performed.
 * @return This varies depending on the operation.
 */
function eventrepeat_nodeapi(&$node, $op) {

  // only continue if this node is event and event_repeat enabled
  if (variable_get('event_nodeapi_'. $node->type, 'never') == 'never' &&
      variable_get('eventrepeat_nodeapi_'. $node->type, 0) == 0) {
    return;
  }

  //this holds the old start time of an event, for use in mass updates
  static $old_times;

  //for all ops except settings, make sure that the node is event & eventrepeat enabled before executing
  switch ($op) {

    case 'validate':
        // no break. both need a node with a formatted date and event_start
        // and event_end set, 'validate' for the previewing and 'submit' for
        // update/insert.

    case 'presave':

      // TODO: what if the user wants to "turn off" the repeating event
      // the user is trying to turn off repeating events for all future events
      if (($node->eventrepeat_FREQ == '' || $node->eventrepeat_FREQ == 'NONE') && ($node->eventrepeat_edit_type == 'future' || $node->eventrepeat_edit_type == 'all')) {
        form_set_error('eventrepeat_FREQ', t('Trying to remove a repeat setting from a repeating event is not currently supported. Please try deleting the events you don\'t want instead.'));
      }

      //validate the repeat end date
      _eventrepeat_validate_form_date('eventrepeat_end', t('Repeat end'), $node);

      // TODO: this would cause an odd error if the person wanted
      // to remove the repeating sequence so I removed it for now.
      //if they have some repeat options chosen,
      // make sure a repeat type is selected
      /*
      if ($node->eventrepeat_FREQ == 'NONE' &&
        ($node->eventrepeat_COUNT
         || $node->eventrepeat_INTERVAL > 1
         || $node->eventrepeat_BYDAY
         || $node->eventrepeat_BYWEEKNO
         || $node->eventrepeat_BYMONTH
         || $node->eventrepeat_BYMONTHDAY
         || $node->eventrepeat_BYYEARDAY
         || $node->eventrepeat_EXDATE)
      ) {
        form_set_error('eventrepeat_FREQ', t('You must select a Repeat Type if you want this event to repeat.'));
      }
      */

      //warn if user entered values for both repeat end and COUNT
      if ($node->eventrepeat_end && $node->eventrepeat_COUNT) {
        form_set_error('eventrepeat_end', t('\'Repeat end date\' and \'count\' cannot both be set--select only one to provide a valid end point for the sequence'));
      }

      // TODO: if this is unsupported, can we just use end date after the initial render?
      //warn if user tries to edit a sequence based on COUNT--this is currently not supported
      if ($node->eventrepeat_rid && $node->eventrepeat_COUNT) {
        form_set_error('eventrepeat_COUNT', t('Editing a sequence which uses the  \'count\' parameter is not currently supported. You may need to delete this event.'));
      }

      break;

    case 'delete':
        static $mass_delete;
        global $form_values;
        //determine what kind of delete we're doing here.  check $form_values to see if it's a mass delete
        //and mark it as such if so.  otherwise just delete the node from the detail table
        if ($form_values['eventrepeat_delete_type'][$node->nid] &&
          $form_values['eventrepeat_delete_type'][$node->nid] != 'this') {

          $mass_delete = TRUE;
          _eventrepeat_delete_nodes($form_values['eventrepeat_delete_type'][$node->nid], $node);
          //this line necessary to clean up mods after eventrepeat
          node_invoke_nodeapi($node, 'delete');
        }
        else {
          db_query("DELETE FROM {eventrepeat_nodes} WHERE nid = %d", $node->nid);

          //if not a mass delete, check to see if this is the last repeat event in this sequence.  if so, then
          //delete the sequence
          if (!$mass_delete) {
            db_query("DELETE FROM {eventrepeat} WHERE rid = %d", $node->eventrepeat_rid);
          }
        }


      break;
    case 'load':

      if (variable_get('event_nodeapi_'. $node->type, 'never') != 'never') {

        //if the old start time hasn't been saved to the update code yet, then save it.  this is a total hack,
        //but i don't know any other way to do it
        if (!$old_times && $form_state['values']['op'] == t('Submit')) {
          $old_times = db_query('SELECT e.event_start, e.event_end, e.timezone FROM {event} e WHERE e.nid = %d', $node->nid);
          if (db_num_rows($old_times)) {
            $old_times = db_fetch_object($old_times);
            $old_times->eventrepeat_old_times = TRUE;
            _eventrepeat_update_nodes($old_times, NULL);
          }
        }

        //if it's a repeat node, grab the repeat data for the node
        if (variable_get('eventrepeat_nodeapi_'. $node->type, 0) == 1) {
          $object = db_fetch_object(db_query('SELECT e_r.rid, repeat_RRULE, repeat_end
            FROM {eventrepeat} e_r INNER JOIN {eventrepeat_nodes} e_r_n ON
            e_r.rid = e_r_n.rid WHERE e_r_n.nid = %d', $node->nid));

          //if this node is in a repeat sequence, parse the RRULE, and return repeat data to the node
          if ($object->rid) {

            //append the repeat tag to the title if it's an event page
            if (arg(0) == 'event') {
              $node->title = theme("eventrepeat_title_tag", $node->title);
            }
            $items = _eventrepeat_parse_ical($object->repeat_RRULE);
            return array('eventrepeat_rid' => $object->rid,
                         'eventrepeat_FREQ' => $items[0]['FREQ'],
                         'eventrepeat_COUNT' => $items[0]['COUNT'],
                         'eventrepeat_INTERVAL' => $items[0]['INTERVAL'],
                         'eventrepeat_BYDAY' => $items[0]['BYDAY'],
                         'eventrepeat_BYWEEKNO' => $items[0]['BYWEEKNO'],
                         'eventrepeat_BYMONTH' => $items[0]['BYMONTH'],
                         'eventrepeat_BYMONTHDAY' => $items[0]['BYMONTHDAY'],
                         'eventrepeat_BYYEARDAY' => $items[0]['BYYEARDAY'],
                         'eventrepeat_EXDATE' => $items[0]['EXDATE'],
                         'eventrepeat_end' => $object->repeat_end, // placeholder in case the end date processing changes
                         'eventrepeat_endyear' => $object->repeat_end ? _event_date('Y', $object->repeat_end) : 0,
                         'eventrepeat_endmonth' => $object->repeat_end ? _event_date('n', $object->repeat_end) : 0,
                         'eventrepeat_endday' => $object->repeat_end ? _event_date('d', $object->repeat_end) : 0
            );
          }
        }
      }
      break;

    case 'insert':

        // add a new exception to the list if needed
        _eventrepeat_form_add_exception($node);

        // if this node has eventrepeat_FREQ info
        // remember that we strip this for new instances
        // in _eventrepeat_render_nodes
        if ($node->eventrepeat_FREQ != '' && $node->eventrepeat_FREQ != 'NONE') {
          _eventrepeat_save_repeat($node);
        }

      break;


    case 'update':
      //setting a static indicator here--this case will more than likely get called
      //multiple times as nodes are updated, but we only want the repeat update
      //itself to run once per page load.
      static $update_run = NULL;
      if (!isset($update_run)) {
        $update_run = TRUE;
        // add a new exception to the list if needed
        _eventrepeat_form_add_exception($node);

        //determine what kind of update we're doing here.  it's either all (from current date
        //forward), future (current node and all future nodes) or just an individual node update
        //pass all and future to the mass edit code
        if ($node->eventrepeat_edit_type == 'future') {
          //we have to update the existing nodes first before we update the repeat pattern
          //only update the repeat pattern if the node update was successful.
          if (_eventrepeat_update_nodes($node, $node->event_start) === TRUE) {
            _eventrepeat_save_repeat($node);
          }
        }
        elseif ($node->eventrepeat_edit_type == 'all') {
          //we have to update the existing nodes first before we update the repeat pattern
          //only update the repeat pattern if the node update was successful.
          if (_eventrepeat_update_nodes($node, time()) === TRUE) {
            _eventrepeat_save_repeat($node);
          }
        }
        elseif ($node->eventrepeat_edit_type == 'this') {
          //if it's an individual edit, and admin has selected that they are to be removed from sequences,
          //then delete from detail table
          if (!variable_get('eventrepeat_single_edit_in_sequence', FALSE)) {
            db_query("DELETE FROM {eventrepeat_nodes} WHERE nid = %d", $node->nid);
          }
        }
        // the user is turning a non-repeat event into a repeat event
        elseif (($node->eventrepeat_FREQ != '' && $node->eventrepeat_FREQ != 'NONE') && !$node->eventrepeat_rid) {
          _eventrepeat_save_repeat($node);
        }
      }
      break;


    case 'view':
      break;
  }
}

/**
 * @defgroup eventrepeat_event Functions which use hooks in event.module
 */

/**
 * hook_event_edit_upcoming implementation
 *
 * @ingroup eventrepeat_event
 * @param $node The node the action is being performed on (not a full node).
 * @return None--edits are made directly to the $node object prior to rendering
 */
function eventrepeat_event_edit_upcoming(&$node) {

  //if this node appears in the detail table, then add the repeat tag to it
  if (db_result(db_query('SELECT nid FROM {eventrepeat_nodes} WHERE nid = %d', $node->nid))) {
    $node->title = theme("eventrepeat_title_tag", $node->title);
  }
}

/**
 * hook_event_load implementation
 *
 * @ingroup eventrepeat_event
 * @param $year The year of the rendered calendar view.
 * @param $month The month of the rendered calendar view.
 * @param $day The day of the rendered calendar view. No leading zeroes.
 * @param $view The calendar view being rendered
 * @param $types unused
 * @param $terms unused
 * @return None--allows for node creation which only.
 */
function eventrepeat_event_load($year, $month, $day, $view, $types, $terms) {

  //only should be run once per page call
  static $execute;
  if (!$execute) {
    $execute = 1;

    //default $view to either the default view setting, or 'month' if it's not set
    $view = $view ? $view : variable_get('event_overview', 'month');

    //first thing is to determine the exact range that's going to be rendered, and calculate start and end timestamps
    $calendar_period_start = _event_mktime(23, 59, 59, $month, $day, $year);
    switch ($view) {
      case 'day':
        $endtime = $calendar_period_start;
        break;

      case 'week':
        //calculate the end of the week (not perfect, but close enough!)
        $endtime = $calendar_period_start + (86400*7);
        break;

      case 'month':
        //generate the end date based on number of days in the month
        $endtime = gmmktime(23, 59, 59, $month, gmdate('t', $calendar_period_start), $year);
        break;

      case 'table':
      case 'list':
        //table/list end is simply the start day of the viewing period plus the event_table_duration.  if duration
        //is specified as an argument, then make sure it's not longer than a year.  if not, then just use the
        //table duration default or 30 days
        $duration = arg(7);
        $numberofdays = $duration && $duration < 366 ? $duration : variable_get('event_table_duration', '30');
        $endtime = gmmktime(23, 59, 59, $month, $day + $numberofdays, $year);
        break;

      default:
        return;
    }

    //check here to see if the user is viewing a date outside of the rendering range. if so, warn and exit
    $curtime = time();
    $curtime_end = gmmktime(23, 59, 59, (int) gmdate('n', $curtime), (int) gmdate('j', $curtime),
      (int) gmdate('Y', $curtime));
    $render_support = $curtime_end + (variable_get('eventrepeat_render_support', 2000) * 86400);
    if ($endtime > $render_support) {
      drupal_set_message(t('This calendar view is outside of the range of repeat event support'));
      return;
    }

    //check here to see if the calendar is outside of the initial render range. if so, then render all repeat
    //sequences through the end time of the calendar period
    $past_initial_render = $curtime_end - 86400 + (variable_get('eventrepeat_initial_render', 90) * 86400);
    if ($endtime > $past_initial_render) {
      _eventrepeat_render_nodes('all', $endtime, FALSE, FALSE, FALSE);
    }
  }
}

/**
 * @defgroup eventrepeat_support Functions that support the eventrepeat system
 */

/**
 * Helper function that corrects for date GMT date changes based on timezone
 *
 * @ingroup eventrepeat_support
 * @param $starthour The start hour of the event.
 * @param $startminute The start minute of the event.
 * @param $offset The timezone offset of the event.
 * @return Day offset in seconds.
 */
function _eventrepeat_day_correction($starthour, $startminute, $offset) {

  //if the GMT day for the event falls on a different day than the local day, we have to account for that
  //since the event_repeat_calendar map table has all of it's day info in GMT
  //here we check that by adding the timezone offset to the starthour--if the result is less than zero, then
  //we need to add a day to the rendering date, and if it's greater than 24, we need to subtract a day from the
  //rendering date
  if ($offset > 0) {
    $day_offset = (((($starthour * 3600) + ($startminute * 60)) + $offset) > 86400) ? -86400 : 0;
  }
  elseif ($offset < 0) {
    $day_offset = (((($starthour * 3600) + ($startminute * 60)) + $offset) < 0) ? 86400 : 0;
  }
  else {
    $day_offset = 0;
  }

  return $day_offset;
}

/**
 * Helper function that gives information on the number of each of the days in the month for each of the seven days
 *
 * @ingroup eventrepeat_support
 * @param $master_day The day of the week of the first day of the month.
 * @param $days_in_month The number of days in the month.
 * @return An array in the same order as the days of the week (Sun-Sat), with values of 0 for days of the week with 4 occurrences, and 1 for days of the week with 5 occurrences.
 */
function _eventrepeat_day_in_month_incrementer($master_day, $days_in_month) {

  //some days of the week in a month occur 4 times, and some occur 5 times.  here we're building an array that will
  //store data of this kind for the current month.  any days of the week that occur five times in the month are given
  //a value of 1 in this array, so that the $master_day_in_month_R counter can be adjusted correctly for these days
  $day_in_month_incrementer = array(0, 0, 0, 0, 0, 0, 0);
  for ($i = 29; $i <= $days_in_month; $i++) {
    $day_in_month_incrementer[$master_day] = 1;
    $master_day == 6 ? $master_day = 0 : $master_day++;
  }
  return $day_in_month_incrementer;
}

/**
 * Helper function that handles mass deletion of nodes in a repeat sequence
 *
 * @ingroup eventrepeat_support
 * @param $op The operation to be performed (either 'this', 'all', or 'future').
 * @param $node The root node which the mass delete operation is based on.
 * @return None.
 */
function _eventrepeat_delete_nodes($op, $node) {

  global $form_values;

  //unset eventrepeat_delete_type for this nid to prevent this function from being called mutliple times
  //also set the current GMT timestamp
  unset($form_values['eventrepeat_delete_type'][$node->nid]);
  $curtime = time();

  //delete the entry in the repeat_nodes table for the current node being deleted
  db_query("DELETE FROM {eventrepeat_nodes} WHERE nid = %d", $node->nid);

  //set the proper timestamp for the nodes to delete query.  for 'all' this will be from the current
  //date forward, and for 'future', it will be from the node's event->start time--if this is an update
  //delete, it will be just after the passed in update end time
  if ($op == 'all') {
    $timestamp = $curtime;
  }
  elseif ($op == 'future') {
    $timestamp = $node->event_start;
  }

  //pull all of the nids for nodes that are to be deleted from this sequence
  $result = db_query("SELECT e_r_n.nid FROM {eventrepeat_nodes} e_r_n INNER JOIN {event} e ON
    e_r_n.nid = e.nid WHERE e_r_n.rid = %d AND e.event_start >= %d", $node->eventrepeat_rid, $timestamp);

  //loop through the nids,  calling node_delete for all nodes in the result set
  while ($node_to_delete = db_fetch_object($result)) {
    node_delete($node_to_delete->nid);
  }

  //pull the start times for the remaining nodes in this repeat sequence
  $result = db_query("SELECT e.event_start FROM {eventrepeat_nodes} e_r_n INNER JOIN {event} e ON
    e_r_n.nid = e.nid WHERE e_r_n.rid = %d ORDER BY e.event_start DESC", $node->eventrepeat_rid);
  $num_rows = FALSE;
  if ($last_rendered = db_fetch_object($result)) {
    //there are still nodes in the repeat sequence--in this case we want to keep the repeat sequence intact
    //since it may still need to be mass edited/deleted, but we also want to end creation of any new nodes,
    //so here we grab the start date of the latest node in the sequence and set the end date of the sequence equal
    //to it.
    $last_rendered = gmmktime(23, 59, 59,
      (int) gmdate('n', $last_rendered->event_start),
      (int) gmdate('j', $last_rendered->event_start),
      (int) gmdate('Y', $last_rendered->event_start)
    );
    db_query("UPDATE {eventrepeat} SET repeat_end = %d, repeat_last_rendered = %d WHERE rid = %d",
      $last_rendered, $last_rendered, $node->eventrepeat_rid);
  }
  else {
    //no nodes left in the sequence, so delete the repeat data
    db_query("DELETE FROM {eventrepeat} WHERE rid = %d", $node->eventrepeat_rid);
  }
}

/**
 * Generates the repeat setting form under the repeat tab, and saves repeat data to the repeat tables.
 *
 * @ingroup eventrepeat_support
 * @param $node Either the $node object from the db or the node object from $_POST['edit']
 * @return Fully themed page containing the repeat setting form.
 */
function theme_eventrepeat_form($node) {

  //if the node is part of a repeat sequence, then construct the radio buttons for mass edit
  // TODO: review default change: moved to default of future because
  // otherwise I found that users would keep trying to change exceptions and
  // make other repeat pattern updates on occurrences by accident.
  // The "this" options is also the most destructive of the three.
  // The "future" maps a bit better to how iCal works.
  if ($node->eventrepeat_rid) {
    $form['eventrepeat_rid'] = array('#type' => 'hidden', '#value' => $node->eventrepeat_rid);
    $options = array(
      'this' => t('This occurrence only'),
      'future' => t('This occurrence and all future occurrences'),
      'all' => t('All occurrences')
    );
    $form['eventrepeat_edit_type'] = array(
      '#type' => 'radios',
      '#title' => t('Apply edit(s) to'),
      '#default_value' => variable_get('eventrepeat_default_edit_type', 'future'),
      '#options' => $options,
      '#description' => t('\'This occurrence and all future occurrences\' will edit repeat events from the date of the selected node forward, \'All occurrences\' will edit repeat events after today\'s date. <br />Note: editing a single occurrence will remove it from the repeat sequence.'),
      '#weight' => -12
    );
  }

  // figure out what we are expanding and create the main fieldset
  $exception_collapsed = ($node->eventrepeat_EXDATE) ? FALSE : TRUE;
  $advanced_collapsed = ($node->eventrepeat_INTERVAL > 1
    || $node->eventrepeat_BYDAY
    || $node->eventrepeat_BYMONTH
    || $node->eventrepeat_BYMONTHDAY
    || $node->eventrepeat_BYYEARDAY
    || $node->eventrepeat_BYWEEKNO
  ) ? FALSE: TRUE;
  $collapsed = TRUE;
  if (($node->eventrepeat_FREQ != '' && $node->eventrepeat_FREQ != 'NONE')
    || $exception_collapsed == FALSE
    || $advanced_collapsed == FALSE
  ) {
    $collapsed = FALSE;
  }
  $help = '<p>'. l(t('Need help creating a repeat pattern?'), 'eventrepeat/help', array('target' => '_blank')) .'<br />'. t('NOTE: Editing an existing repeat pattern maps previously created events to the new pattern, in sequential order, on all dates from the date where the edit is performed.') .'</p>';
  $form['eventrepeat'] = array(
    '#type' => 'fieldset',
    '#title' => t('Repeat'),
    '#tree' => FALSE,
    '#collapsible' => TRUE,
    '#collapsed' => $collapsed,
    '#weight' => -12,
    '#description' => $help,
  );

    //link to user help for repeat patterns
  //$form['eventrepeat_advanced']['help'] = array('#type' => 'markup', '#value' => '<p>'. l(t('Need help creating a repeat pattern?'), 'eventrepeat/help') .'<br />'. t('NOTE: Editing an existing repeat pattern maps previously created events to the new pattern, in sequential order, on all dates from the date where the edit is performed.') .'</p>');


  //FREQ param select box
  $options = array(
    'NONE' => t('none'),
    'DAILY' => t('Daily'),
    'WEEKLY' => t('Weekly'),
    'MONTHLY' => t('Monthly'),
    'YEARLY' => t('Yearly')
  );
  $form['eventrepeat']['eventrepeat_FREQ'] = array(
    '#type' => 'select',
    '#title' => t('Repeat type'),
    '#default_value' => $node->eventrepeat_FREQ ? $node->eventrepeat_FREQ : 'NONE',
    '#options' => $options,
    '#description' => t('select \'none\' to disable repeats for this event')
  );

  //put end controls in a group to make them less confusing
  $form['eventrepeat']['end_controls'] = array(
    '#type' => 'fieldset',
    '#title' => t('End Settings'),
    '#collapsible' => TRUE,
    '#description' => t('Select either the end date or the number of times you want this event to repeat.')
  );

  //date box for end date
  $form['eventrepeat']['end_controls']['end_date'] = array(
    '#type' => 'eventrepeat_date',
    '#title' => t('Repeat end date'),
    '#process' => array('_eventrepeat_form_date' => array($node, 'eventrepeat_end'))
  );

  // the - or - markup
  $form['eventrepeat']['end_controls']['or'] = array('#type' => 'markup', '#value' => '<b>---'. t('OR')  .'---</b>');

  // TODO: if editing based on count is unsupported, can we just use end date after the initial render?
  //COUNT param select box
  $options = array(0 => '--'. t('Select') .'--');
  for ($i = 2; $i <= 100; $i++) {
    $options[$i] = $i;
  }
  $form['eventrepeat']['end_controls']['eventrepeat_COUNT'] = array(
    '#type' => 'select',
    '#title' => t('count'),
    '#default_value' => $node->eventrepeat_COUNT ? $node->eventrepeat_COUNT : 0,
    '#options' => $options,
    '#description' => t('Determines the number of repeat nodes that will be created for the repeat sequence')
  );

  // Add the advanced options
  $form['eventrepeat'][] = theme('eventrepeat_form_advanced', $node, $advanced_collapsed);

  // Removed the exception form because it wasn't working right. You can just delete the instances you want anyway.
  //$form['eventrepeat'][] = theme('eventrepeat_form_exception', $node, $exception_collapsed);

  return $form;

}

/**
 * theme the advanced fieldset of form elements
 */
function theme_eventrepeat_form_advanced($node, $advanced_collapsed) {
  $options = array();

  $show_advanced = variable_get('eventrepeat_showadvanced', array());
  if ($show_advanced['eventrepeat_INTERVAL'] == FALSE
    && $show_advanced['eventrepeat_BYDAY'] == FALSE
    && $show_advanced['eventrepeat_BYWEEKNO'] == FALSE
    && $show_advanced['eventrepeat_BYMONTH'] == FALSE
    && $show_advanced['eventrepeat_BYMONTHDAY'] == FALSE
    && $show_advanced['eventrepeat_BYYEARDAY'] == FALSE
  ) {
    return;
  }
  $form = array();

  // start the advanced fieldset
  $form['eventrepeat_advanced'] = array(
    '#type' => 'fieldset',
    '#title' => t('Advanced'),
    '#collapsible' => TRUE,
    '#collapsed' => $advanced_collapsed,
    '#tree' => FALSE,
  );

  //INTERVAL param select box
  if ($show_advanced['eventrepeat_INTERVAL']) {
    for ($i = 1; $i <= 60; $i++) {
      $options[$i] = $i;
    }
    $form['eventrepeat_advanced']['eventrepeat_INTERVAL'] = array(
      '#type' => 'select',
      '#title' => t('Interval'),
      '#default_value' => ($node->eventrepeat_INTERVAL) ? $node->eventrepeat_INTERVAL : 1, '#options' => $options,
      '#description' => t('Frequency of repeat: 1 = every, 2 = every other, 3 = every 3rd, etc.')
    );
  }

  //set days of the week array, and copy it into $dow
  $options = array(
    'SU' => t('Sunday'),
    'MO' => t('Monday'),
    'TU' => t('Tuesday'),
    'WE' => t('Wednesday'),
    'TH' => t('Thursday'),
    'FR' => t('Friday'),
    'SA' => t('Saturday')
  );
  $dow = $options;

  //set the count options array
  $dowcount = array(
    '1' => t('1st'),
    '2' => t('2nd'),
    '3' => t('3rd'),
    '4' => t('4th'),
    '5' => t('5th'),
    '-1' => t('Last'),
    '-2' => t('Next to Last'),
    '-3' => t('2nd from Last'),
    '-4' => t('3rd from Last'),
    '-5' => t('4th from Last')
  );

  //loop through each day of the week, looping through each count option, and build an array of all combinations
  foreach ($dow as $dowkey => $dowvalue) {
    foreach ($dowcount as $countkey => $countvalue) {
      $options[$countkey . $dowkey] = $countvalue .' '. $dowvalue;
    }
  }

  //BYDAY param select box
  if ($show_advanced['eventrepeat_BYDAY']) {
    $form['eventrepeat_advanced']['eventrepeat_BYDAY'] = array(
      '#type' => 'select',
      '#title' => t('Day(s)'),
      '#default_value' => $node->eventrepeat_BYDAY ? $node->eventrepeat_BYDAY : '',
      '#options' => $options, '#description' => t('Determines what day(s) of the week/month this event repeats on (by day of the week).  Lots of options available, scroll down!'),
      '#attributes' => array('size' => '7'),
      '#multiple' => TRUE
    );
  }


  //BYMONTH param select box
  if ($show_advanced['eventrepeat_BYMONTH']) {
    $options = array(
      1 => t('January'),
      2 => t('February'),
      3 => t('March'),
      4 => t('April'),
      5 => t('May'),
      6 => t('June'),
      7 => t('July'),
      8 => t('August'),
      9 => t('September'),
      10 => t('October'),
      11 => t('November'),
      12 => t('December'),
    );
    $form['eventrepeat_advanced']['eventrepeat_BYMONTH'] = array(
      '#type' => 'select',
      '#title' => t('Month(s)'),
      '#default_value' => $node->eventrepeat_BYMONTH ? $node->eventrepeat_BYMONTH : '',
      '#options' => $options,
      '#description' => t('Selects what month(s) of the year this event repeats on'),
      '#multiple' => TRUE,
      '#size' => 5,
    );
  }