/phpical/functions/parse/overlapping_events.php
PHP | 274 lines | 178 code | 26 blank | 70 comment | 50 complexity | 720b9d11b0695d34d46c36b4de567a42 MD5 | raw file
- <?php
- // function to determine maximum necessary columns per day
- // actually an algorithm to get the smallest multiple for two numbers
- function kgv($a, $b) {
- $x = $a;
- $y = $b;
- while ($x != $y) {
- if ($x < $y) $x += $a;
- else $y += $b;
- }
- return $x;
- }
- // merge a given range into $ol_ranges. Returns the merged $ol_ranges.
- // if count = -2, treat as a "delete" call (for removeOverlap)
- // Why -2? That way, there's less fudging of the math in the code.
- function merge_range($ol_ranges, $start, $end, $count = 0) {
- foreach ($ol_ranges as $loop_range_key => $loop_range) {
-
- if ($start < $end) {
- // handle ranges between $start and $loop_range['start']
- if ($start < $loop_range['start']) {
- $new_ol_ranges[] = array('count' => $count, 'start' => $start, 'end' => min($loop_range['start'], $end));
- $start = $loop_range['start'];
- }
- // $start is always >= $loop_range['start'] at this point.
- // handles ranges between $loop_range['start'] and $loop_range['end']
- if ($loop_range['start'] < $end && $start < $loop_range['end']) {
- // handles ranges between $loop_range['start'] and $start
- if ($loop_range['start'] < $start) {
- $new_ol_ranges[] = array('count' => $loop_range['count'], 'start' => $loop_range['start'], 'end' => $start);
- }
- // handles ranges between $start and $end (where they're between $loop_range['start'] and $loop_range['end'])
- $new_count = $loop_range['count'] + $count + 1;
- if ($new_count >= 0) {
- $new_ol_ranges[] = array('count' => $new_count, 'start' => $start, 'end' => min($loop_range['end'], $end));
- }
- // handles ranges between $end and $loop_range['end']
- if ($loop_range['end'] > $end) {
- $new_ol_ranges[] = array('count' => $loop_range['count'], 'start' => $end, 'end' => $loop_range['end']);
- }
- $start = $loop_range['end'];
- } else {
- $new_ol_ranges[] = $loop_range;
- }
- } else {
- $new_ol_ranges[] = $loop_range;
- }
- }
- // Catches anything left over.
- if ($start < $end) {
- $new_ol_ranges[] = array('count' => $count, 'start' => $start, 'end' => $end);
- }
- return $new_ol_ranges;
- }
- // Finds the highest value of 'count' in $ol_ranges
- function find_max_overlap($ol_ranges) {
- $count = 0;
- foreach ($ol_ranges as $loop_range) {
- if ($count < $loop_range['count'])
- $count = $loop_range['count'];
- }
- return $count;
- }
- // Merges overlapping blocks
- function flatten_ol_blocks($event_date, $ol_blocks, $new_block_key) {
- global $master_array;
- // Loop block = each other block in the array, the ones we're merging into new block.
- // New block = the changed block that caused the flatten_ol_blocks call. Everything gets merged into this.
- $new_block = $ol_blocks[$new_block_key];
- reset($ol_blocks);
- while ($loop_block_array = each($ol_blocks)) {
- $loop_block_key = $loop_block_array['key'];
- $loop_block = $loop_block_array['value'];
- // only compare with other blocks
- if ($loop_block_key != $new_block_key) {
- // check if blocks overlap
- if (($loop_block['blockStart'] < $new_block['blockEnd']) && ($loop_block['blockEnd'] > $new_block['blockStart'])) {
- // define start and end of merged overlap block
- if ($new_block['blockStart'] > $loop_block['blockStart']) $ol_blocks[$new_block_key]['blockStart'] = $loop_block['blockStart'];
- if ($new_block['blockEnd'] < $loop_block['blockEnd']) $ol_blocks[$new_block_key]['blockEnd'] = $loop_block['blockEnd'];
- $ol_blocks[$new_block_key]['events'] = array_merge($new_block['events'], $loop_block['events']);
- $new_block['events'] = $ol_blocks[$new_block_key]['events'];
- foreach ($loop_block['overlapRanges'] as $ol_range) {
- $new_block['overlapRanges'] = merge_range($new_block['overlapRanges'], $ol_range['start'], $ol_range['end'], $ol_range['count']);
- }
- $ol_blocks[$new_block_key]['overlapRanges'] = $new_block['overlapRanges'];
- $ol_blocks[$new_block_key]['maxOverlaps'] = find_max_overlap($new_block['overlapRanges']);
- foreach ($ol_blocks[$new_block_key]['events'] as $event) {
- $master_array[$event_date][$event['time']][$event['key']]['event_overlap'] = $ol_blocks[$new_block_key]['maxOverlaps'];
- }
- unset($ol_blocks[$loop_block_key]);
- reset($ol_blocks);
- }
- }
- }
- return $ol_blocks;
- }
- // Builds $overlap_array structure, and updates event_overlap in $master_array for the given events.
- // For a given date,
- // - check to see if the event's already in a block, and if so, add it.
- // - make sure the new block doesn't overlap another block, and if so, merge the blocks.
- // - check that there aren't any events we already passed that we should handle.
- // - "flatten" the structure again, merging the blocks.
- // $overlap_array structure:
- // array of ($event_dates)
- // array of unique overlap blocks (no index) -
- // $overlap_block structure
- // 'blockStart' - $start_time of block - earliest $start_time of the events in the block.
- // Shouldn't be any overlap w/ a different overlap block in that day (as if they overlap, they get merged).
- // 'blockEnd' - $end_time of block - latest $end_time of the events in the block.
- // 'maxOverlaps' - max number of overlaps for the whole block (highest 'count' in overlapRanges)
- // 'events' - array of event "pointers" (no index) - each event in the block.
- // 'time' - $start_time of event in the block
- // 'key' - $uid of event
- // 'overlapRanges' - array of time ranges + overlap counts (no index) - the specific overlap info.
- // Shouldn't be any overlap w/ the overlap ranges in a given overlap_block - if there is overlap, the block should be split.
- // 'count' - number of overlaps that time range (can be zero if that range has no overlaps).
- // 'start' - start_time for the overlap block.
- // 'end' - end_time for the overlap block.
- function checkOverlap($event_date, $event_time, $uid) {
- global $master_array, $overlap_array;
- if (!isset($event_date)) return;
- $event = $master_array[$event_date][$event_time][$uid];
- // Copy out the array - we replace this at the end.
- $ol_day_array = @$overlap_array[$event_date];
- $draw_end = $event['event_end'];
- if (isset($event['display_end'])) $draw_end = $event['display_end'];
- $drawTimes = drawEventTimes($event['event_start'], $draw_end);
- // Track if $event has been merged in, so we don't re-add the details to 'event' or 'overlapRanges' multiple times.
- $already_merged_once = false;
- // First, check the existing overlap blocks, see if the event overlaps with any.
- if (isset($ol_day_array)) {
- foreach ($ol_day_array as $loop_block_key => $loop_ol_block) {
- // Should $event be in this $ol_block? If so, add it.
- if ($loop_ol_block['blockStart'] < $drawTimes['draw_end'] && $loop_ol_block['blockEnd'] > $drawTimes['draw_start']) {
- // ... unless it's already in the $ol_block
- if (!in_array(array('time' => $drawTimes['draw_start'], 'key' => $uid), $loop_ol_block['events'])) {
- $loop_ol_block['events'][] = array('time' => $drawTimes['draw_start'], 'key' => $uid);
- if ($loop_ol_block['blockStart'] > $drawTimes['draw_start']) $loop_ol_block['blockStart'] = $drawTimes['draw_start'];
- if ($loop_ol_block['blockEnd'] < $drawTimes['draw_end']) $loop_ol_block['blockEnd'] = $drawTimes['draw_end'];
- // Merge in the new overlap range
- $loop_ol_block['overlapRanges'] = merge_range($loop_ol_block['overlapRanges'], $drawTimes['draw_start'], $drawTimes['draw_end']);
- $loop_ol_block['maxOverlaps'] = find_max_overlap($loop_ol_block['overlapRanges']);
- foreach ($loop_ol_block['events'] as $max_overlap_event) {
- $master_array[$event_date][$max_overlap_event['time']][$max_overlap_event['key']]['event_overlap'] = $loop_ol_block['maxOverlaps'];
- }
- $ol_day_array[$loop_block_key] = $loop_ol_block;
- $ol_day_array = flatten_ol_blocks($event_date, $ol_day_array, $loop_block_key);
- $already_merged_once = true;
- break;
- // Handle repeat calls to checkOverlap - semi-bogus since the event shouldn't be created more than once, but this makes sure we don't get an invalid event_overlap.
- } else {
- $master_array[$event_date][$event_time][$uid]['event_overlap'] = $loop_ol_block['maxOverlaps'];
- }
- }
- }
- }
- // Then, check all the events, make sure there isn't a new overlap that we need to create.
- foreach ($master_array[$event_date] as $time_key => $time) {
- // Skip all-day events for overlap purposes.
- if ($time_key != '-1') {
- foreach ($time as $loop_event_key => $loop_event) {
- // Make sure we haven't already dealt with the event, and we're not checking against ourself.
- if ($loop_event['event_overlap'] == 0 && $loop_event_key != $uid) {
- $loopDrawTimes = drawEventTimes($loop_event['event_start'], $loop_event['display_end']);
- if ($loopDrawTimes['draw_start'] < $drawTimes['draw_end'] && $loopDrawTimes['draw_end'] > $drawTimes['draw_start']) {
- if ($loopDrawTimes['draw_start'] < $drawTimes['draw_start']) {
- $block_start = $loopDrawTimes['draw_start'];
- } else {
- $block_start = $drawTimes['draw_start'];
- }
- if ($loopDrawTimes['draw_end'] > $drawTimes['draw_end']) {
- $block_end = $loopDrawTimes['draw_end'];
- } else {
- $block_end = $drawTimes['draw_end'];
- }
- $events = array(array('time' => $loopDrawTimes['draw_start'], 'key' => $loop_event_key));
- $overlap_ranges = array(array('count' => 0, 'start' => $loopDrawTimes['draw_start'], 'end' => $loopDrawTimes['draw_end']));
- // Only add $event if we haven't already put it in a block
- if (!$already_merged_once) {
- $events[] = array('time' => $drawTimes['draw_start'], 'key' => $uid);
- $overlap_ranges = merge_range($overlap_ranges, $drawTimes['draw_start'], $drawTimes['draw_end']);
- $already_merged_once = true;
- }
- $ol_day_array[] = array('blockStart' => $block_start, 'blockEnd' => $block_end, 'maxOverlaps' => 1, 'events' => $events, 'overlapRanges' => $overlap_ranges);
- foreach ($events as $max_overlap_event) {
- $master_array[$event_date][$max_overlap_event['time']][$max_overlap_event['key']]['event_overlap'] = 1;
- }
- // Make sure we pass in the key of the newly added item above.
- end($ol_day_array);
- $last_day_key = key($ol_day_array);
- $ol_day_array = flatten_ol_blocks($event_date, $ol_day_array, $last_day_key);
- }
- }
- }
- }
- }
- $overlap_array[$event_date] = $ol_day_array;
- //for debugging the checkOverlap function
- //if ($event_date == '20050506') {
- //print 'Date: ' . $event_date . ' / Time: ' . $event_time . ' / Key: ' . $uid . "<br />\n";
- //print '<pre>';
- //print_r($master_array[$event_date]);
- //print_r($overlap_array[$event_date]);
- //print '</pre>';
- //}
- }
- // Remove an event from the overlap data.
- // This could be completely bogus, since overlap array is empty when this gets called in my tests, but I'm leaving it in anyways.
- function removeOverlap($ol_start_date, $ol_start_time, $ol_key) {
- global $master_array, $overlap_array;
- if (isset($overlap_array[$ol_start_date])) {
- if (sizeof($overlap_array[$ol_start_date]) > 0) {
- $ol_end_time = $master_array[$ol_start_date][$ol_start_time][$ol_key]['event_end'];
- foreach ($overlap_array[$ol_start_date] as $block_key => $block) {
- if (in_array(array('time' => $ol_start_time, 'key' => $ol_key), $block['events'])) {
- // Check if this is a 2-event block (i.e., there's no block left when we remove $ol_key
- // and if so, just unset it and move on.
- if (count($block['events']) == 2) {
- foreach ($block['events'] as $event) {
- $master_array[$ol_start_date][$event['time']][$event['key']]['event_overlap'] = 0;
- }
- unset($overlap_array[$ol_start_date][$block_key]);
- } else {
- // remove $ol_key from 'events'
- $event_key = array_search(array('time' => $ol_start_time, 'key' => $ol_key), $block['events']);
- unset($overlap_array[$ol_start_date][$block_key]['events'][$event_key]);
- // These may be bogus, since we're not using drawEventTimes.
- // "clean up" 'overlapRanges' and calc the new maxOverlaps.
- // use the special "-2" count to tell merge_range we're deleting.
- $overlap_array[$ol_start_date][$block_key]['overlapRanges'] = merge_range($block['overlapRanges'], $ol_start_time, $ol_end_time, -2);
- $overlap_array[$ol_start_date][$block_key]['maxOverlaps'] = find_max_overlap($block['overlapRanges']);
- // recreate blockStart and blockEnd from the other events, and fix maxOverlap while we're at it.
- $blockStart = $ol_end_time;
- $blockEnd = $ol_start_time;
- foreach ($overlap_array[$ol_start_date][$block_key]['events'] as $event) {
- $blockStart = min($blockStart, $event['time']);
- $blockEnd = max($blockEnd, $master_array[$ol_start_date][$event['time']][$event['key']]['event_end']);
- $master_array[$ol_start_date][$event['time']][$event['key']]['event_overlap'] = $overlap_array[$ol_start_date][$block_key]['maxOverlaps'];
- }
- $overlap_array[$ol_start_date][$block_key]['blockStart'] = $blockStart;
- $overlap_array[$ol_start_date][$block_key]['blockEnd'] = $blockEnd;
- }
- }
- }
- }
- }
- }
- ?>