X-Git-Url: http://wagnertech.de/git?a=blobdiff_plain;f=WEB-INF%2Flib%2FttWeekViewHelper.class.php;h=1144cea6bfe42d7e9352369a93eda1c699cc43a4;hb=f787edd7045299de3885c052d243b446f7324ea0;hp=b6dfdd73e51d47426275c4525c9228f345423fef;hpb=621c2592fb3db0dfdea6be497381d847938f708c;p=timetracker.git

diff --git a/WEB-INF/lib/ttWeekViewHelper.class.php b/WEB-INF/lib/ttWeekViewHelper.class.php
index b6dfdd73..1144cea6 100644
--- a/WEB-INF/lib/ttWeekViewHelper.class.php
+++ b/WEB-INF/lib/ttWeekViewHelper.class.php
@@ -29,6 +29,336 @@
 // ttWeekViewHelper class groups together functions used in week view.
 class ttWeekViewHelper {
 
+  // getRecordsForInterval - returns time records for a user for a given interval of dates.
+  static function getRecordsForInterval($start_date, $end_date, $includeFiles = false) {
+    global $user;
+
+    $user_id = $user->getUser();
+    $group_id = $user->getGroup();
+    $org_id = $user->org_id;
+
+    $sql_time_format = "'%k:%i'"; //  24 hour format.
+    if ('%I:%M %p' == $user->time_format)
+      $sql_time_format = "'%h:%i %p'"; // 12 hour format for MySQL TIME_FORMAT function.
+
+    $result = array();
+    $mdb2 = getConnection();
+
+    $client_field = null;
+    if ($user->isPluginEnabled('cl'))
+      $client_field = ', c.id as client_id, c.name as client';
+
+    $custom_field_1 = null;
+    if ($user->isPluginEnabled('cf')) {
+      $custom_fields = new CustomFields();
+      $cf_1_type = $custom_fields->fields[0]['type'];
+      if ($cf_1_type == CustomFields::TYPE_TEXT) {
+        $custom_field_1 = ', cfl.value as cf_1_value';
+      } elseif ($cf_1_type == CustomFields::TYPE_DROPDOWN) {
+        $custom_field_1 = ', cfo.id as cf_1_id, cfo.value as cf_1_value';
+      }
+    }
+
+    if ($includeFiles) {
+      $filePart = ', if(Sub1.entity_id is null, 0, 1) as has_files';
+      $fileJoin =  " left join (select distinct entity_id from tt_files".
+      " where entity_type = 'time' and group_id = $group_id and org_id = $org_id and status = 1) Sub1".
+      " on (l.id = Sub1.entity_id)";
+    }
+
+    $left_joins = " left join tt_projects p on (l.project_id = p.id)".
+      " left join tt_tasks t on (l.task_id = t.id)";
+    if ($user->isPluginEnabled('cl'))
+      $left_joins .= " left join tt_clients c on (l.client_id = c.id)";
+    if ($user->isPluginEnabled('cf')) {
+      if ($custom_fields->fields[0]['type'] == CustomFields::TYPE_TEXT)
+        $left_joins .= 'left join tt_custom_field_log cfl on (l.id = cfl.log_id and cfl.status = 1) left join tt_custom_field_options cfo on (cfl.value = cfo.id) ';
+      elseif ($custom_fields->fields[0]['type'] == CustomFields::TYPE_DROPDOWN)
+        $left_joins .= 'left join tt_custom_field_log cfl on (l.id = cfl.log_id and cfl.status = 1) left join tt_custom_field_options cfo on (cfl.option_id = cfo.id) ';
+    }
+    $left_joins .= $fileJoin;
+
+    $sql = "select l.id as id, l.date as date, TIME_FORMAT(l.start, $sql_time_format) as start,".
+      " TIME_FORMAT(sec_to_time(time_to_sec(l.start) + time_to_sec(l.duration)), $sql_time_format) as finish,".
+      " TIME_FORMAT(l.duration, '%k:%i') as duration, p.id as project_id, p.name as project,".
+      " t.id as task_id, t.name as task, l.comment, l.billable, l.invoice_id $client_field $custom_field_1 $filePart".
+      " from tt_log l $left_joins".
+      " where l.date >= '$start_date' and l.date <= '$end_date'".
+      " and l.user_id = $user_id and l.group_id = $group_id and l.org_id = $org_id and l.status = 1".
+      " order by l.date, p.name, t.name, l.start, l.id";
+    $res = $mdb2->query($sql);
+    if (!is_a($res, 'PEAR_Error')) {
+      while ($val = $res->fetchRow()) {
+        if($val['duration']=='0:00')
+          $val['finish'] = '';
+        $result[] = $val;
+      }
+    } else return false;
+
+    return $result;
+  }
+
+  // getDataForWeekView - builds an array to render a table of durations and comments for a week view.
+  // In a week view we want one row representing the same attributes to have 7 values for each day of week.
+  // We identify similar records by a combination of client, billable, project, task, and custom field values.
+  // This will allow us to extend the feature when more custom fields are added.
+  //
+  // "cl:546,bl:1,pr:23456,ts:27464,cf_1:example text"
+  // The above means client 546, billable, project 23456, task 27464, custom field text "example text".
+  //
+  // "cl:546,bl:0,pr:23456,ts:27464,cf_1:7623"
+  // The above means client 546, not billable, project 23456, task 27464, custom field option id 7623.
+  //
+  // Daily comments are implemented as alternate rows following week durations (when enabled).
+  // For example: row_0 - new entry durations, row_1 - new entry daily comments,
+  //              row_2 - existing entry durations, row_3 - existing entry comments, etc.
+  //
+  // Description of $dataArray format that the function returns.
+  // $dataArray = array(
+  //   array( // Row 0. This is a special, one-off row for a new week entry with empty values.
+  //     'row_id' => null, // Row identifier. Null for a new entry.
+  //     'label' => 'New entry:', // Human readable label for the row describing what this time entry is for.
+  //     'day_0' => array('control_id' => '0_day_0', 'tt_log_id' => null, 'duration' => null), // control_id is row_id plus day header for column.
+  //     'day_1' => array('control_id' => '0_day_1', 'tt_log_id' => null, 'duration' => null),
+  //     'day_2' => array('control_id' => '0_day_2', 'tt_log_id' => null, 'duration' => null),
+  //     'day_3' => array('control_id' => '0_day_3', 'tt_log_id' => null, 'duration' => null),
+  //     'day_4' => array('control_id' => '0_day_4', 'tt_log_id' => null, 'duration' => null),
+  //     'day_5' => array('control_id' => '0_day_5', 'tt_log_id' => null, 'duration' => null),
+  //     'day_6' => array('control_id' => '0_day_6', 'tt_log_id' => null, 'duration' => null)
+  //   ),
+  //
+  //   array( // Row 1. This row represents daily comments for a new entry in row above (row 0).
+  //     'row_id' => null,
+  //     'label' => 'Notes:',
+  //     'day_0' => array('control_id' => '1_day_0', 'tt_log_id' => null, 'note' => null),
+  //     'day_1' => array('control_id' => '1_day_1', 'tt_log_id' => null, 'note' => null),
+  //     'day_2' => array('control_id' => '1_day_2', 'tt_log_id' => null, 'note' => null),
+  //     'day_3' => array('control_id' => '1_day_3', 'tt_log_id' => null, 'note' => null),
+  //     'day_4' => array('control_id' => '1_day_4', 'tt_log_id' => null, 'note' => null),
+  //     'day_5' => array('control_id' => '1_day_5', 'tt_log_id' => null, 'note' => null),
+  //     'day_6' => array('control_id' => '1_day_6', 'tt_log_id' => null, 'note' => null)
+  //   ),
+  //
+  //   array( // Row 2.
+  //     'row_id' => 'cl:546,bl:1,pr:23456,ts:27464,cf_1:7623_0',
+  //     'label' => 'Anuko - Time Tracker - Coding - Option 2',
+  //     'day_0' => array('control_id' => '2_day_0', 'tt_log_id' => 12345, 'duration' => '00:00'),
+  //     'day_1' => array('control_id' => '2_day_1', 'tt_log_id' => 12346, 'duration' => '01:00'),
+  //     'day_2' => array('control_id' => '2_day_2', 'tt_log_id' => 12347, 'duration' => '02:00'),
+  //     'day_3' => array('control_id' => '2_day_3', 'tt_log_id' => null, 'duration' => null),
+  //     'day_4' => array('control_id' => '2_day_4', 'tt_log_id' => 12348, 'duration' => '04:00'),
+  //     'day_5' => array('control_id' => '2_day_5', 'tt_log_id' => 12349, 'duration' => '04:00'),
+  //     'day_6' => array('control_id' => '2_day_6', 'tt_log_id' => null, 'duration' => null)
+  //   ),
+  //   array( // Row 3.
+  //     'row_id' => 'cl:546,bl:1,pr:23456,ts:27464,cf_1:7623_0_notes',
+  //     'label' => 'Notes:',
+  //     'day_0' => array('control_id' => '3_day_0', 'tt_log_id' => 12345, 'note' => 'Comment one'),
+  //     'day_1' => array('control_id' => '3_day_1', 'tt_log_id' => 12346, 'note' => 'Comment two'),
+  //     'day_2' => array('control_id' => '3_day_2', 'tt_log_id' => 12347, 'note' => 'Comment three'),
+  //     'day_3' => array('control_id' => '3_day_3', 'tt_log_id' => null, 'note' => null),
+  //     'day_4' => array('control_id' => '3_day_4', 'tt_log_id' => 12348, 'note' => 'Comment four'),
+  //     'day_5' => array('control_id' => '3_day_5', 'tt_log_id' => 12349, 'note' => 'Comment five'),
+  //     'day_6' => array('control_id' => '3_day_6', 'tt_log_id' => null, 'note' => null)
+  //   )
+  // );
+  static function getDataForWeekView($records, $dayHeaders) {
+    global $user;
+    global $i18n;
+
+    $dataArray = array();
+
+    // Construct the first row for a brand new entry.
+    $dataArray[] = array('row_id' => null,'label' => $i18n->get('form.week.new_entry').':'); // Insert row.
+    // Insert empty cells with proper control ids.
+    for ($i = 0; $i < 7; $i++) {
+      $control_id = '0_'. $dayHeaders[$i];
+      $dataArray[0][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'duration' => null);
+    }
+    if ($user->isPluginEnabled('wvns')) {
+      // Construct the second row for daily comments for a brand new entry.
+      $dataArray[] = array('row_id' => null,'label' => $i18n->get('label.notes').':'); // Insert row.
+      // Insert empty cells with proper control ids.
+      for ($i = 0; $i < 7; $i++) {
+        $control_id = '1_'. $dayHeaders[$i];
+        $dataArray[1][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'note' => null);
+      }
+    }
+
+    // Iterate through records and build $dataArray cell by cell.
+    foreach ($records as $record) {
+      // Create row id without suffix.
+      $row_id_no_suffix = ttWeekViewHelper::makeRowIdentifier($record);
+      // Handle potential multiple records with the same attributes by using a numerical suffix.
+      $suffix = 0;
+      $row_id = $row_id_no_suffix.'_'.$suffix;
+      $day_header = substr($record['date'], 8); // Day number in month.
+      while (ttWeekViewHelper::cellExists($row_id, $day_header, $dataArray)) {
+        $suffix++;
+        $row_id = $row_id_no_suffix.'_'.$suffix;
+      }
+      // Find row.
+      $pos = ttWeekViewHelper::findRow($row_id, $dataArray);
+      if ($pos < 0) {
+        // Insert row for durations.
+        $dataArray[] = array('row_id' => $row_id,'label' => ttWeekViewHelper::makeRowLabel($record));
+        $pos = ttWeekViewHelper::findRow($row_id, $dataArray);
+        // Insert empty cells with proper control ids.
+        for ($i = 0; $i < 7; $i++) {
+          $control_id = $pos.'_'. $dayHeaders[$i];
+          $dataArray[$pos][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'duration' => null);
+        }
+        // Insert row for comments.
+        if ($user->isPluginEnabled('wvns')) {
+          $dataArray[] = array('row_id' => $row_id.'_notes','label' => $i18n->get('label.notes').':');
+          $pos++;
+          // Insert empty cells with proper control ids.
+          for ($i = 0; $i < 7; $i++) {
+            $control_id = $pos.'_'. $dayHeaders[$i];
+            $dataArray[$pos][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'note' => null);
+          }
+          $pos--;
+        }
+      }
+      // Insert actual cell data from $record (one cell only).
+      $dataArray[$pos][$day_header] = array('control_id' => $pos.'_'. $day_header, 'tt_log_id' => $record['id'],'duration' => $record['duration']);
+      // Insert existing comment from $record into the comment cell.
+      if ($user->isPluginEnabled('wvns')) {
+        $pos++;
+        $dataArray[$pos][$day_header] = array('control_id' => $pos.'_'. $day_header, 'tt_log_id' => $record['id'],'note' => $record['comment']);
+      }
+    }
+    return $dataArray;
+  }
+
+  // prePopulateFromPastWeeks - is a complementary function to getDataForWeekView.
+  // It builds an "empty" $dataArray with only labels present. Labels are taken from
+  // the most recent active past week, up to 5 weeks back from now.
+  // This is a data entry acceleration feature to help users quickly populate their
+  // regular entry list for a new week, even after a long vacation.
+  static function prePopulateFromPastWeeks($startDate, $dayHeaders) {
+    global $user;
+    global $i18n;
+
+    // First, determine past week start and end dates.
+    $objDate = new DateAndTime(DB_DATEFORMAT, $startDate);
+    $objDate->decDay(7);
+    $pastWeekStartDate = $objDate->toString(DB_DATEFORMAT);
+    $objDate->incDay(6);
+    $pastWeekEndDate = $objDate->toString(DB_DATEFORMAT);
+    unset($objDate);
+
+    // Obtain past week(s) records.
+    $records = ttWeekViewHelper::getRecordsForInterval($pastWeekStartDate, $pastWeekEndDate);
+    // Handle potential situation of no records by re-trying for up to 4 more previous weeks (after a long vacation, etc.).
+    if (!$records) {
+      for ($i = 0; $i < 4; $i++) {
+        $objDate = new DateAndTime(DB_DATEFORMAT, $pastWeekStartDate);
+        $objDate->decDay(7);
+        $pastWeekStartDate = $objDate->toString(DB_DATEFORMAT);
+        $objDate->incDay(6);
+        $pastWeekEndDate = $objDate->toString(DB_DATEFORMAT);
+        unset($objDate);
+
+        $records = ttWeekViewHelper::getRecordsForInterval($pastWeekStartDate, $pastWeekEndDate);
+        // Break out of the loop if we found something.
+        if ($records) break;
+      }
+    }
+
+    // Construct the first row for a brand new entry.
+    $dataArray[] = array('row_id' => null,'label' => $i18n->get('form.week.new_entry').':'); // Insert row.
+    // Insert empty cells with proper control ids.
+    for ($i = 0; $i < 7; $i++) {
+      $control_id = '0_'. $dayHeaders[$i];
+      $dataArray[0][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'duration' => null);
+    }
+    if ($user->isPluginEnabled('wvns')) {
+      // Construct the second row for daily comments for a brand new entry.
+      $dataArray[] = array('row_id' => null,'label' => $i18n->get('label.notes').':'); // Insert row.
+      // Insert empty cells with proper control ids.
+      for ($i = 0; $i < 7; $i++) {
+        $control_id = '1_'. $dayHeaders[$i];
+        $dataArray[1][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'note' => null);
+      }
+    }
+
+    // Iterate through records and build an "empty" $dataArray.
+    foreach ($records as $record) {
+      // Create row id with 0 suffix. In prepopulated view, we only need one row for similar records.
+      $row_id = ttWeekViewHelper::makeRowIdentifier($record).'_0';
+      // Find row.
+      $pos = ttWeekViewHelper::findRow($row_id, $dataArray);
+      if ($pos < 0) {
+        // Insert row for durations.
+        $dataArray[] = array('row_id' => $row_id,'label' => ttWeekViewHelper::makeRowLabel($record));
+        $pos = ttWeekViewHelper::findRow($row_id, $dataArray);
+        // Insert empty cells with proper control ids.
+        for ($i = 0; $i < 7; $i++) {
+          $control_id = $pos.'_'. $dayHeaders[$i];
+          $dataArray[$pos][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'duration' => null);
+        }
+        // Insert row for comments.
+        if ($user->isPluginEnabled('wvns')) {
+          $dataArray[] = array('row_id' => $row_id.'_notes','label' => $i18n->get('label.notes').':');
+          $pos++;
+          // Insert empty cells with proper control ids.
+          for ($i = 0; $i < 7; $i++) {
+            $control_id = $pos.'_'. $dayHeaders[$i];
+            $dataArray[$pos][$dayHeaders[$i]] = array('control_id' => $control_id, 'tt_log_id' => null,'note' => null);
+          }
+          $pos--;
+        }
+      }
+    }
+
+    return $dataArray;
+  }
+
+  // cellExists is a helper function for getDataForWeekView() to see if a cell with a given label
+  // and a day header already exists.
+  static function cellExists($row_id, $day_header, $dataArray) {
+    foreach($dataArray as $row) {
+      if ($row['row_id'] == $row_id && !empty($row[$day_header]['duration']))
+        return true;
+    }
+    return false;
+  }
+
+  // findRow returns an existing row position in $dataArray, -1 otherwise.
+  static function findRow($row_id, $dataArray) {
+    $pos = 0; // Row position in array.
+    foreach($dataArray as $row) {
+      if ($row['row_id'] == $row_id)
+        return $pos;
+      $pos++; // Increment for search.
+    }
+    return -1; // Row not found.
+  }
+
+  // getDayTotals calculates total durations for each day from the existing data in $dataArray.
+  static function getDayTotals($dataArray, $dayHeaders) {
+    $dayTotals = array();
+
+    // Insert label.
+    global $i18n;
+    $dayTotals['label'] = $i18n->get('label.day_total').':';
+
+    foreach ($dataArray as $row) {
+      foreach($dayHeaders as $dayHeader) {
+        if (array_key_exists($dayHeader, $row)) {
+          $minutes = ttTimeHelper::toMinutes($row[$dayHeader]['duration']);
+          $dayTotals[$dayHeader] += $minutes;
+        }
+      }
+    }
+    // Convert minutes to hh:mm for display.
+    foreach($dayHeaders as $dayHeader) {
+      $dayTotals[$dayHeader] = ttTimeHelper::minutesToDuration($dayTotals[$dayHeader]);
+    }
+    return $dayTotals;
+  }
+
   // getDayHeadersForWeek - obtains day column headers for week view, which are simply day numbers in month.
   static function getDayHeadersForWeek($start_date) {
     $dayHeaders = array();
@@ -65,6 +395,34 @@ class ttWeekViewHelper {
     return $lockedDays;
   }
 
+  // makeRowIdentifier - builds a string identifying a row for a week view from a single record properties.
+  //                     Note that the return value is without a suffix.
+  // For example:
+  // "cl:546,bl:0,pr:23456,ts:27464,cf_1:example text"
+  // "cl:546,bl:1,pr:23456,ts:27464,cf_1:7623"
+  static function makeRowIdentifier($record) {
+    global $user;
+    // Start with client.
+    if ($user->isPluginEnabled('cl'))
+      $row_identifier = $record['client_id'] ? 'cl:'.$record['client_id'] : '';
+    // Add billable flag.
+    if (!empty($row_identifier)) $row_identifier .= ',';
+    $row_identifier .= 'bl:'.$record['billable'];
+    // Add project.
+    $row_identifier .= $record['project_id'] ? ',pr:'.$record['project_id'] : '';
+    // Add task.
+    $row_identifier .= $record['task_id'] ? ',ts:'.$record['task_id'] : '';
+    // Add custom field 1.
+    if ($user->isPluginEnabled('cf')) {
+      if ($record['cf_1_id'])
+        $row_identifier .= ',cf_1:'.$record['cf_1_id'];
+      else if ($record['cf_1_value'])
+        $row_identifier .= ',cf_1:'.$record['cf_1_value'];
+    }
+
+    return $row_identifier;
+  }
+
   // makeRowLabel - builds a human readable label for a row in week view,
   // which is a combination ot record properties.
   // Client - Project - Task - Custom field 1.
@@ -114,4 +472,161 @@ class ttWeekViewHelper {
     // Return value.
     return substr($remaninder, $posBegin, $posEnd - $posBegin);
   }
+
+  // dateFromDayHeader calculates date from start date and day header in week view.
+  static function dateFromDayHeader($start_date, $day_header) {
+    $objDate = new DateAndTime(DB_DATEFORMAT, $start_date);
+    $currentDayHeader = (string) $objDate->getDate(); // It returns an int on first call.
+    if (strlen($currentDayHeader) == 1)               // Which is an implementation detail of DateAndTime class.
+      $currentDayHeader = '0'.$currentDayHeader;      // Add a 0 for single digit day.
+    $i = 1;
+    while ($currentDayHeader != $day_header && $i < 7) {
+      // Iterate through remaining days to find a match.
+      $objDate->incDay();
+      $currentDayHeader = $objDate->getDate(); // After incDay it returns a string with leading 0, when necessary.
+      $i++;
+    }
+    return $objDate->toString(DB_DATEFORMAT);
+  }
+
+  // insertDurationFromWeekView - inserts a new record in log tables from a week view post.
+  static function insertDurationFromWeekView($fields, $custom_fields, $err) {
+    global $i18n;
+    global $user;
+
+    // Determine date for a new entry.
+    $entry_date = ttWeekViewHelper::dateFromDayHeader($fields['start_date'], $fields['day_header']);
+    $objEntryDate = new DateAndTime(DB_DATEFORMAT, $entry_date);
+
+    // Prohibit creating entries in future.
+    if (!$user->future_entries && $fields['browser_today']) {
+      $objBrowserToday = new DateAndTime(DB_DATEFORMAT, $fields['browser_today']);
+      if ($objEntryDate->after($objBrowserToday)) {
+        $err->add($i18n->get('error.future_date'));
+        return false;
+      }
+    }
+
+    // Prepare an array of fields for regular insert function.
+    $fields4insert = array();
+    $fields4insert['user_id'] = $user->getUser();
+    $fields4insert['group_id'] = $user->getGroup();
+    $fields4insert['org_id'] = $user->org_id;
+    $fields4insert['date'] = $entry_date;
+    $fields4insert['duration'] = $fields['duration'];
+    $fields4insert['client'] = ttWeekViewHelper::parseFromWeekViewRow($fields['row_id'], 'cl');
+    $fields4insert['billable'] = ttWeekViewHelper::parseFromWeekViewRow($fields['row_id'], 'bl');
+    $fields4insert['project'] = ttWeekViewHelper::parseFromWeekViewRow($fields['row_id'], 'pr');
+    $fields4insert['task'] = ttWeekViewHelper::parseFromWeekViewRow($fields['row_id'], 'ts');
+    $fields4insert['note'] = $fields['note'];
+
+    // Try to insert a record.
+    $id = ttTimeHelper::insert($fields4insert);
+    if (!$id) return false; // Something failed.
+
+    // Insert custom field if we have it.
+    $result = true;
+    $cf_1 = ttWeekViewHelper::parseFromWeekViewRow($fields['row_id'], 'cf_1');
+    if ($custom_fields && $cf_1) {
+      if ($custom_fields->fields[0]['type'] == CustomFields::TYPE_TEXT)
+        $result = $custom_fields->insert($id, $custom_fields->fields[0]['id'], null, $cf_1);
+      elseif ($custom_fields->fields[0]['type'] == CustomFields::TYPE_DROPDOWN)
+        $result = $custom_fields->insert($id, $custom_fields->fields[0]['id'], $cf_1, null);
+    }
+
+    return $result;
+  }
+
+  // modifyDurationFromWeekView - modifies a duration of an existing record from a week view post.
+  static function modifyDurationFromWeekView($fields, $err) {
+    global $i18n;
+    global $user;
+
+    // Possible errors: 1) Overlap if the existing record has start time. 2) Going beyond 24 hour boundary.
+    if (!ttWeekViewHelper::canModify($fields['tt_log_id'], $fields['duration'], $err))
+      return false;
+
+    $mdb2 = getConnection();
+    $duration = $fields['duration'];
+    $tt_log_id = $fields['tt_log_id'];
+    $user_id = $user->getUser();
+    $sql = "update tt_log set duration = '$duration' where id = $tt_log_id and user_id = $user_id";
+    $affected = $mdb2->exec($sql);
+    if (is_a($affected, 'PEAR_Error'))
+      return false;
+
+    return true;
+  }
+
+  // canModify - determines if an  already existing tt_log record
+  // can be modified with a new user-provided duration.
+  static function canModify($tt_log_id, $new_duration, $err) {
+    global $i18n;
+    $mdb2 = getConnection();
+
+    // Determine if we have start time in record, as further checking does not makes sense otherwise.
+    $sql = "select user_id, date, start, duration from tt_log  where id = $tt_log_id";
+    $res = $mdb2->query($sql);
+    if (!is_a($res, 'PEAR_Error')) {
+      if (!$res->numRows()) {
+        $err->add($i18n->get('error.db')); // This is not expected.
+        return false;
+      }
+      $val = $res->fetchRow();
+      $oldDuration = $val['duration'];
+      if (!$val['start'])
+        return true; // There is no start time in the record, therefore safe to modify.
+    }
+
+    // We do have start time.
+    $newMinutes = ttTimeHelper::toMinutes($new_duration);
+    if ($newMinutes < 0) {
+      // Negative durations are not supported when start time is defined.
+      $err->add($i18n->get('error.field'), $i18n->get('label.duration'));
+      return false;
+    }
+
+    // Quick test if new duration is less than already existing.
+    $oldMinutes = ttTimeHelper::toMinutes($oldDuration);
+    if ($newMinutes < $oldMinutes)
+      return true; // Safe to modify.
+
+    // Does the new duration put the record beyond 24:00 boundary?
+    $startMinutes = ttTimeHelper::toMinutes($val['start']);
+    $newEndMinutes = $startMinutes + $newMinutes;
+    if ($newEndMinutes > 1440) {
+      // Invalid duration, as new duration puts the record beyond current day.
+      $err->add($i18n->get('error.field'), $i18n->get('label.duration'));
+      return false;
+    }
+
+    // Does the new duration causes the record to overlap with others?
+    $user_id = $val['user_id'];
+    $date = $val['date'];
+    $startMinutes = ttTimeHelper::toMinutes($val['start']);
+    $start = ttTimeHelper::toAbsDuration($startMinutes);
+    $finish = ttTimeHelper::toAbsDuration($newEndMinutes);
+    if (ttTimeHelper::overlaps($user_id, $date, $start, $finish, $tt_log_id)) {
+      $err->add($i18n->get('error.overlap'));
+      return false;
+    }
+
+    return true; // There are no conflicts, safe to modify.
+  }
+
+  // modifyCommentFromWeekView - modifies a comment in an existing record from a week view post.
+  static function modifyCommentFromWeekView($fields) {
+    global $user;
+
+    $mdb2 = getConnection();
+    $tt_log_id = $fields['tt_log_id'];
+    $comment = $fields['comment'];
+    $user_id = $user->getUser();
+    $sql = "update tt_log set comment = ".$mdb2->quote($fields['comment'])." where id = $tt_log_id and user_id = $user_id";
+    $affected = $mdb2->exec($sql);
+    if (is_a($affected, 'PEAR_Error'))
+      return false;
+
+    return true;
+  }
 }