egroupware/etemplate/inc/class.date_widget.inc.php

<?php
/**
 * eGroupWare eTemplate Extension - Date Widget
 *
 * @link http://www.egroupware.org
 * @author Ralf Becker <RalfBecker@outdoor-training.de>
 * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
 * @copyright 2002-9 by RalfBecker@outdoor-training.de
 * @package etemplate
 * @subpackage extensions
 * @version $Id$
 */

/**
 * eTemplate extension to input or display date and/or time values
 *
 * Contains the following widgets: Date, Date+Time, Time, Hour, Duration
 *
 * Supported attributes: format[,options]
 *  format: '' = timestamps or automatic conversation, or eg. 'Y-m-d H:i:s' for 2002-12-31 23:59:59
 *  options: &1 = year is int-input not selectbox, &2 = show a [Today] button, (html-UI always uses jscal and dont care for &1+&2)
 *           &4 = 1min steps for time (default is 5min, with fallback to 1min if value is not in 5min-steps),
 *           &8 = dont show time for readonly and type date-time if time is 0:00,
 *           &16 = prefix r/o display with dow
 *           &32 = prefix r/o display with week-number
 *			 &64 = prefix r/o display with weeknumber and dow
 *           &128 = no icon to trigger popup, click into input trigers it, also removing the separators to save space
 * This widget is independent of the UI as it only uses etemplate-widgets and has therefor no render-function.
 * Uses the adodb datelibary to overcome the windows-limitation to not allow dates before 1970
 */
class date_widget
{
	/**
	 * exported methods of this class
	 * @var array
	 */
	var $public_functions = array(
		'pre_process' => True,
		'post_process' => True
	);
	/**
	 * available extensions and there names for the editor
	 * @var array
	 */
	var $human_name = array(
		'date'      => 'Date',		// just a date, no time
		'date-time' => 'Date+Time',	// date + time
		'date-timeonly' => 'Time',	// time
		'date-houronly' => 'Hour',	// hour
		'date-duration' => 'Duration', // duration
		'date-since'    => 'Time since',	// time past since given time
		'date-time_today' => 'Date or todays time',
	);
	var $dateformat;	// eg. Y-m-d, d-M-Y
	var $timeformat;	// 12 or 24

	/**
	 * Reference to global jscalencar object
	 *
	 * @var jscalendar
	 */
	var $jscal;

	/**
	 * Constructor of the extension
	 *
	 * @param string $ui '' for html
	 */
	function __construct($ui)
	{
		if ($ui == 'html')
		{
			$this->jscal = $GLOBALS['egw']->jscalendar;
		}
		$this->timeformat = $GLOBALS['egw_info']['user']['preferences']['common']['timeformat'];
		$this->dateformat = $GLOBALS['egw_info']['user']['preferences']['common']['dateformat'];
	}

	/**
	 * pre-processing of the extension
	 *
	 * This function is called before the extension gets rendered
	 *
	 * @param string $name form-name of the control
	 * @param mixed &$value value / existing content, can be modified
	 * @param array &$cell array with the widget, can be modified for ui-independent widgets
	 * @param array &$readonlys names of widgets as key, to be made readonly
	 * @param mixed &$extension_data data the extension can store persisten between pre- and post-process
	 * @param object &$tmpl reference to the template we belong too
	 * @return boolean true if extra label is allowed, false otherwise
	 */
	function pre_process($name,&$value,&$cell,&$readonlys,&$extension_data,&$tmpl)
	{
		//echo "<p>".__METHOD__."($name,$value=".egw_time::to($value).",".array2string($cell).")</p>\n";
		$type = $cell['type'];
		switch ($type)
		{
			case 'date-duration':
				return $this->pre_process_duration($name,$value,$cell,$readonlys,$extension_data,$tmpl);
		}
		list($data_format,$options,$options2) = explode(',',$cell['size']);
		if ($type == 'date-houronly' && empty($data_format)) $data_format = 'H';

		$readonly = $cell['readonly'] || $readonlys || $type == 'date-since';

		if (!$readonly)	// dont set extension-data on readonly, it's not needed and can conflict with other widgets
		{
			$extension_data = array(
				'type'			=> $type,
				'data_format'	=> $data_format,
			);
		}
		// automatic convert db timestamps to unix timestamps, our db class does the reverse on writing them
		if ($value && !$data_format && !is_numeric($value) && ($v = strtotime($value)))
		{
			$value = $value === '0000-00-00 00:00:00' ? null : $v;
		}
		// for date-(time|hour)only widgets we distinct between between 0 and ''/null timestamps
		if (!$value && ($type != 'date-timeonly' && $type != 'date-houronly' || (string)$value === ''))
		{
			$value = array(
				'Y' => '',
				'm' => '',
				'd' => '',
				'H' => '',
				'i' => '',
			);
		}
		elseif (!is_object($value) && $data_format != '')	// we ignore format for objects
		{
			$date = preg_split('/[- \\/.:,]/',$value);
			//echo "date=<pre>"; print_r($date); echo "</pre>";
			$mdy  = preg_split('/[- \\/.:,]/',$data_format);

			if (count($mdy) == 1)	// no seperators, eg. YmdHi
			{
				for($n = $i = 0; $n < strlen($data_format); ++$n)
				{
					$mdy[$n] = $data_format[$n];
					$len = $data_format[$n] == 'Y' ? 4 : 2;
					$date[$n] = substr($value,$i,$len);
					$i += $len;
				}
			}
			$value = array();
			foreach ($date as $n => $dat)
			{
				switch($mdy[$n])
				{
					case 'Y': $value['Y'] = (int) $dat; break;
					case 'm': $value['m'] = (int) $dat; break;
					case 'd': $value['d'] = (int) $dat; break;
					case 'H': $value['H'] = (int) $dat; break;
					case 'i': $value['i'] = (int) $dat; break;
				}
			}
		}
		else
		{
			// for the timeformats we use only seconds, no timezone conversation between server-time and UTC
			if (substr($type,-4) == 'only' && is_numeric($value)) $value -= adodb_date('Z',0);

			$value = egw_time::to($value,'date_array');
		}
		if ($type == 'date-since')
		{
			return $this->pre_process_since($value,$cell);
		}
		$time_0h0 = !(int)$value['H'] && !(int)$value['i'];

		$timeformat = array(3 => 'H', 4 => 'i');
		if ($this->timeformat == '12' && $readonly && $value['H'] !== '')
		{
			$value['a'] = $value['H'] < 12 ? 'am' : 'pm';
			$value['H'] = $value['H'] % 12 ?  $value['H'] % 12 : 12;	// no leading 0 and 0h => 12am
			$timeformat += array(5 => 'a');
		}
		$format = preg_split('/[\\/.-]/',$this->dateformat);

		// no time also if $options&8 and readonly and time=0h0
		if ($type != 'date' && !($readonly && ($options & 8) && $time_0h0))
		{
			$format += $timeformat;
		}
		if ($value['m'] && strchr($this->dateformat,'M') !== false)
		{
			static $month = array('','January','February','March','April','May','June','July','August','September','October','November','December');
			static $substr;
			if (is_null($substr)) $substr = function_exists('mb_substr') ? 'mb_substr' : 'substr';
			static $chars_shortcut;
			if (is_null($chars_shortcut)) $chars_shortcut = (int)lang('3 number of chars for month-shortcut');	// < 0 to take the chars from the end

			$value['M'] = lang($m = substr($month[$value['m']],0,3));	// check if we have a translation of the short-cut
			if ($value['M'] == $m || $substr($value['M'],-1) == '*')	// if not generate one by truncating the translation of the long name
			{
				$value['M'] = $chars_shortcut > 0 ? $substr(lang($month[$value['m']]),0,$chars_shortcut) :
					$substr(lang($month[$value['m']]),$chars_shortcut);
			}
		}
		if ($readonly)	// is readonly
		{
			if ($type == 'date-time_today')
			{
				$today = new egw_time();
				if ($value['Y'].$value['d'].$value['m'] == $today->format('Ymd'))
				{
					$format = $timeformat;
				}
				else
				{
					$format = $dateformat;
				}
			}
			if ($value['H'] === '') unset($value['a']);	// no am/pm if no hour set

			$sep = array(
				1 => $this->dateformat[1],
				2 => $this->dateformat[1],
				3 => ' ',
				4 => ':'
			);
			for ($str='',$n = substr($type,-4) == 'only' ? 3 : 0; $n < count($format); ++$n)
			{
				if ($value[$format[$n]] && $n < 3 || $n >= 3 && ($value[$format[3]] !== '' || $value[$format[4]] !== ''))
				{
					if (!$n && $options & 16 )
					{
						$str = lang(adodb_date('l',adodb_mktime(12,0,0,$value['m'],$value['d'],$value['Y']))).' ';
					}
					if (!$n && $options & 32 )
					{
						$str = lang('Wk').adodb_date('W',adodb_mktime(12,0,0,$value['m'],$value['d'],$value['Y'])).' ';
					}
					if (!$n && $options & 64 )
					{
						$str = lang('Wk').adodb_date('W',adodb_mktime(12,0,0,$value['m'],$value['d'],$value['Y'])).' '.lang(adodb_date('l',adodb_mktime(12,0,0,$value['m'],$value['d'],$value['Y']))).' ';
					}
					$str .= ($str != '' ? $sep[$n] : '') .
						(is_numeric($value[$format[$n]]) ? sprintf('%02d',$value[$format[$n]]) : $value[$format[$n]]);
				}
				if ($type == 'date-houronly') ++$n;	// no minutes
			}
			$value = $str;
			$cell['type'] = 'label';
			if (!$cell['no_lang'])
			{
				$cell['no_lang'] = True;
				$cell['label'] = strlen($cell['label']) > 1 ? lang($cell['label']) : $cell['label'];
			}
			unset($cell['size']);
			return True;
		}
		if ($type == 'date-time_today') $type = 'date-time';	// no special handling for input

		if ($cell['needed'])
		{
			etemplate::$request->set_to_process($name,'ext-'.$type,array(
				'needed' => $cell['needed'],
			));
		}
		$tpl = new etemplate;
		$tpl->init('*** generated fields for date','','',0,'',0,0);	// make an empty template
		// keep the editor away from the generated tmpls
		$tpl->no_onclick = true;

		$types = array(
			'Y' => ($options&1 ? 'int' : 'select-year'),	// if options&1 set, show an int-field
			'm' => 'select-month',
			'M' => 'select-month',
			'd' => 'select-day',
			'H' => 'select-hour',
			'i' => 'select-number'
		);
		$opts = array(
			'H' => $this->timeformat == '12' ? ',0,12' : ',0,23,01',
			'i' => $value['i'] % 5 || $options & 4 ? ',0,59,01' : ',0,59,05' // 5min steps, if ok with value
		);
		$help = array(
			'Y' => 'Year',
			'm' => 'Month',
			'M' => 'Month',
			'd' => 'Day',
			'H' => 'Hour',
			'i' => 'Minute'
		);
		$row = array();
		for ($i=0,$n= substr($type,-4) == 'only' ? 3 : 0; $n < ($type == 'date' ? 3 : 5); ++$n,++$i)
		{
			$dcell = $tpl->empty_cell();
			if ($cell['tabindex']) $dcell['tabindex'] = $cell['tabindex'];
			if (!$i && $cell['accesskey']) $dcell['accesskey'] = $cell['accesskey'];

			// test if we can use jsCalendar
			if ($n == 0 && $this->jscal)
			{
				$dcell['type'] = 'html';
				$dcell['name'] = 'str';
				$cname_parts = array_splice(explode('[',str_replace(']','',$name)), 0, -count(explode('[',str_replace(']','',$cell['name']))));
				$cname = array_shift($cname_parts);
				if ($cname_parts) $cname .= '['.implode('][', $cname_parts).']';
				$jscaloptions =  $cell['onchange'] ? ( ' onchange="'. ( (int)$cell['onchange'] === 1 ? 'this.form.submit();"' : $tmpl->js_pseudo_funcs($cell['onchange'],$cname). '"' ) ) : '' ;
				$value['str'] = $this->jscal->input($name.'[str]',False,$value['Y'],$value['m'],$value['d'],lang($cell['help']),$jscaloptions,false,!($options & 128));
				$n = 2;				// no other fields
				$options &= ~2;		// no set-today button
			}
			else
			{
				$dcell['type'] = $types[$format[$n]];
				$dcell['size'] = $opts[$format[$n]];
				$dcell['name'] = $format[$n];
				$dcell['help'] = lang($help[$format[$n]]).': '.lang($cell['help']);	// note: no lang on help, already done
			}
			if ($n == 4)
			{
				$dcell['label'] = $options & 128 ? '' : ':';	// put a : between hour and minute
			}
			$dcell['no_lang'] = 2;
			$row[$tpl->num2chrs($i)] = &$dcell;
			unset($dcell);

			if ($n == 2 && ($options & 2))	// Today button
			{
				$dcell = $tpl->empty_cell();
				if ($cell['tabindex']) $dcell['tabindex'] = $cell['tabindex'];
				$dcell['name'] = 'today';
				$dcell['label'] = 'Today';
				$dcell['help'] = 'sets today as date';
				$dcell['no_lang'] = True;
				$dcell['needed'] = True;	// to get a button
				$dcell['onchange'] = "this.form.elements['$name"."[Y]'].value='".adodb_date('Y')."'; this.form.elements['$name"."[m]'].value='".adodb_date('n')."';this.form.elements['$name"."[d]'].value='".(0+adodb_date('d'))."'; return false;";
				$dcell['type'] = 'button';
				$row[$tpl->num2chrs(++$i)] = &$dcell;
				unset($dcell);
			}
			if ($n == 2 && $type == 'date-time' && !($options & 128))	// insert some space between date+time
			{
				$dcell = $tpl->empty_cell();
				$dcell['type'] = 'html';
				$dcell['name'] = 'space';
				$value['space'] = ' &nbsp; &nbsp; ';
				$row[$tpl->num2chrs(++$i)] = &$dcell;
				unset($dcell);
			}
			if ($type == 'date-houronly') $n++;	// no minutes
		}
		$tpl->data[0] = array();
		$tpl->data[1] = &$row;
		$tpl->set_rows_cols();
		$tpl->size = ',,,,0';

		$cell['size'] = $cell['name'];
		$cell['type'] = 'template';
		$cell['name'] = $tpl->name;
		$cell['obj'] = &$tpl;
		$cell['span'] .= (strpos($cell['span'],',')===false?',':'').($cell['span']?' ':'').'eTdate';

		return True;	// extra Label is ok
	}

	/**
	 * pre-processing of the duration extension
	 *
	 * Options contain $data_format,$input_format,$hours_per_day,$empty_not_0,$short_labels
	 *  1. data_format: d = days, h = hours, m = minutes, default minutes
	 *	2. input_format: d = days, h = hours, m = minutes,  default hours+days (selectbox), optional % = allow to enter a percent value (no conversation)
	 *	3. hours_per_day: default 8 (workday)
	 *  4. should the widget differ between 0 and empty, which get then returned as NULL
	 *  5. short_labels use d/h/m instead of day/hour/minute
	 *
	 * @param string $name form-name of the control
	 * @param mixed &$value value / existing content, can be modified
	 * @param array &$cell array with the widget, can be modified for ui-independent widgets
	 * @param array &$readonlys names of widgets as key, to be made readonly
	 * @param mixed &$extension_data data the extension can store persisten between pre- and post-process
	 * @param object &$tmpl reference to the template we belong too
	 * @return boolean true if extra label is allowed, false otherwise
	 */
	function pre_process_duration($name,&$value,&$cell,&$readonlys,&$extension_data,&$tmpl)
	{
		//echo "<p>pre_process_duration($name,$value,...) cell[size]='$cell[size]'</p>\n";
		$readonly = $readonlys || $cell['readonly'];
		list($data_format,$input_format,$hours_per_day,$empty_not_0,$short_labels) = explode(',',$cell['size']);
		if (!$hours_per_day) $hours_per_day = 8; // workday is 8 hours
		if (($percent_allowed = strpos($input_format,'%') !== false))
		{
			$input_format = str_replace('%','',$input_format);
		}
		if (!in_array($input_format,array('d','h','dh','m','hm','dhm'))) $input_format = 'dh'; // hours + days

		$unit = $input_format == 'd' ? 'd' : 'h';
		if (!$readonly)	// dont set extension-data on readonly, it's not needed and can conflict with other widgets
		{
			$extension_data = array(
				'type'			=> $cell['type'],
				'data_format'	=> $data_format,
				'unit'          => $unit,
				'input_format'  => $input_format,
				'hours_per_day' => $hours_per_day,
				'percent_allowed'=> $percent_allowed,
				'empty_not_0'   => $empty_not_0,
			);
			$cell['size'] = '4,,/^-?[0-9]*[,.]?[0-9]*'.($percent_allowed ? '%?' : '').'$/';
		}
		if ($value)
		{
			switch($data_format)
			{
				case 'd':
					$value *= $hours_per_day;
					// fall-through
				case 'h': case 'H':
					$value *= 60;
					break;
			}
		}
		$cell['type'] = 'text';
		$cell_name = $cell['name'];
		$cell['name'] .= '[value]';

		if (strpos($input_format,'m') !== false && $value && $value < 60)
		{
			$unit = 'm';
		}
		elseif (strpos($input_format,'d') !== false && $value >= 60*$hours_per_day)
		{
			$unit = 'd';
		}
		$value = $empty_not_0 && (string) $value === '' || !$empty_not_0 && !$value ? '' :
			($unit == 'm' ? (int) $value : round($value / 60 / ($unit == 'd' ? $hours_per_day : 1),3));

		// use decimal separator from user prefs
		if (($sep = $GLOBALS['egw_info']['user']['preferences']['common']['number_format'][0]) && $sep != '.')
		{
			$value = str_replace('.',$sep,$value);
		}
		if (!$readonly && strlen($input_format) > 1) // selectbox to switch between hours and days
		{
			$value = array(
				'value' => $value,
				'unit'  => $unit,
			);
			$tpl = new etemplate;
			$tpl->init('*** generated fields for duration','','',0,'',0,0);	// make an empty template
			// keep the editor away from the generated tmpls
			$tpl->no_onclick = true;

			$selbox =& $tpl->empty_cell('select',$cell_name.'[unit]');
			if (strpos($input_format,'m') !== false) $selbox['sel_options']['m'] = $short_labels ? 'm' : 'minutes';
			if (strpos($input_format,'h') !== false) $selbox['sel_options']['h'] = $short_labels ? 'h' : 'hours';
			if (strpos($input_format,'d') !== false) $selbox['sel_options']['d'] = $short_labels ? 'd' : 'days';
			if ($cell['tabindex']) $selbox['tabindex'] = $cell['tabindex'];

			$tpl->data[0] = array();
			$tpl->data[1] =array(
				'A' => $cell,
				'B' => $selbox,
			);
			$tpl->set_rows_cols();
			$tpl->size = ',,,,0';

			unset($cell['size']);
			$cell['type'] = 'template';
			$cell['name'] = $tpl->name;
			unset($cell['label']);
			$cell['obj'] = &$tpl;
		}
		elseif (!$readonly || $value)
		{
			$cell['no_lang'] = 2;
			$cell['label'] .= ($cell['label'] ? ' ' : '') . '%s ';
			switch($unit)
			{
				case 'm': $cell['label'] .= $short_labels ? 'm' : lang('minutes'); break;
				case 'h': $cell['label'] .= $short_labels ? 'h' : lang('hours'); break;
				case 'd': $cell['label'] .= $short_labels ? 'd' : lang('days'); break;
			}
		}
		return True;	// extra Label is ok
	}

	/**
	 * pre-processing of the time since extension
	 *
	 * @param array &$value value / existing content, can be modified
	 * @param array &$cell array with the widget, can be modified for ui-independent widgets
	 * @return boolean true if extra label is allowed, false otherwise
	 */
	function pre_process_since(&$value,&$cell)
	{
		static $unit2label = array(
			'Y' => 'years',
			'm' => 'month',
			'd' => 'days',
			'H' => 'hours',
			'i' => 'minutes',
			's' => 'seconds',
		);
		static $unit2s = array(
			'Y' => 31536000,
			'm' => 2628000,
			'd' => 86400,
			'H' => 3600,
			'i' => 60,
			's' => 1,
		);
		$cell = boetemplate::empty_cell('label','',array('label'=>$cell['label']));

		if ((string)$value['Y'] !== '')
		{
			if (!is_object($GLOBALS['egw']->datetime))
			{
				$GLOBALS['egw']->datetime = new egw_datetime();
			}
			$now_s = time() + $GLOBALS['egw']->datetime->tz_offset;	// time() is server-time and we need a user-time

			$val_s = mktime($value['H'],$value['i'],$value['s'],$value['m'],$value['d'],$value['Y']);

			$diff_s = $now_s - $val_s;

			foreach($unit2s as $unit => $unit_s)
			{
				if ($diff_s >= $unit_s || $unit == 's')
				{
					$value = round($diff_s/$unit_s,1).' '.lang($unit2label[$unit]);
					break;
				}
				//echo "<p>$unit: diff_s=$diff_s >= $unit_s --> continue</p>\n";
			}
		}
		else
		{
			$value = '';
		}
		return true;
	}

	/**
	 * postprocessing method, called after the submission of the form
	 *
	 * It has to copy the allowed/valid data from $value_in to $value, otherwise the widget
	 * will return no data (if it has a preprocessing method). The framework insures that
	 * the post-processing of all contained widget has been done before.
	 *
	 * Only used by select-dow so far
	 *
	 * @param string $name form-name of the widget
	 * @param mixed &$value the extension returns here it's input, if there's any
	 * @param mixed &$extension_data persistent storage between calls or pre- and post-process
	 * @param boolean &$loop can be set to true to request a re-submision of the form/dialog
	 * @param object &$tmpl the eTemplate the widget belongs too
	 * @param mixed &value_in the posted values (already striped of magic-quotes)
	 * @return boolean true if $value has valid content, on false no content will be returned!
	 */
	function post_process($name,&$value,&$extension_data,&$loop,&$tmpl,$value_in)
	{
		//echo "<p>date_widget::post_process('$name','$extension_data[type]','$extension_data[data_format]') value="; print_r($value); echo ", value_in="; print_r($value_in); echo "</p>\n";
		if (!isset($value) && !isset($value_in))
		{
			return False;
		}
		if ($extension_data['type'] == 'date-duration')
		{
			if (is_array($value))	// template with selectbox
			{
				$unit = $value['unit'];
				$value = $value['value'];
			}
			elseif (!preg_match('/^-?[0-9]*[,.]?[0-9]*'.($extension_data['percent_allowed'] ? '%?' : '').'$/',$value_in))
			{
				etemplate::set_validation_error($name,lang("'%1' is not a valid floatingpoint number !!!",$value_in));
				return false;
			}
			else
			{
				$value = $value_in;
				$unit = $extension_data['unit'];
			}
			if ($extension_data['percent_allowed'] && substr($value,-1) == '%')
			{
				return true;
			}
			if ($value === '' && $extension_data['empty_not_0'])	// we differ between 0 and empty, which get returned as null
			{
				$value = null;
				return true;
			}
			$value = (int) round(str_replace(',','.',$value) * ($unit == 'm' ? 1 : (60 * ($unit == 'd' ? $extension_data['hours_per_day'] : 1))));

			switch($extension_data['data_format'])
			{
				case 'd':
					$value /= (float) $extension_data['hours_per_day'];
					// fall-through
				case 'h': case 'H':
					$value /= 60.0;
					break;
			}
			return true;
		}
		$no_date = substr($extension_data['type'],-4) == 'only';

		if ($value['today'])
		{
			$set = array('Y','m','d');
			foreach($set as $d)
			{
				$value[$d] = adodb_date($d);
			}
		}
		if (isset($value_in['str']) && !empty($value_in['str']))
		{
			if (!is_array($value))
			{
				$value = array();
			}
			$value += $this->jscal->input2date($value_in['str'],False,'d','m','Y');
		}
		if ($value['d'] || $no_date &&
			(isset($value['H']) && $value['H'] !== '' || isset($value['i']) && $value['i'] !== ''))
		{
			if ($value['d'])
			{
				if (!$value['m'])
				{
					$value['m'] = adodb_date('m');
				}
				if (!$value['Y'])
				{
					$value['Y'] = adodb_date('Y');
				}
				elseif ($value['Y'] < 100)
				{
					$value['Y'] += $value['Y'] < 30 ? 2000 : 1900;
				}
			}
			else	// for the timeonly field
			{
				$value['d'] = $value['m'] = 1;
				$value['Y'] = 1970;
			}
			// checking the date is a correct one
			if (!checkdate($value['m'],$value['d'],$value['Y']))
			{
				etemplate::set_validation_error($name,lang("'%1' is not a valid date !!!",
					common::dateformatorder($value['Y'],$value['m'],$value['d'],true)));
			}
			$data_format = $extension_data['data_format'];
			if (empty($data_format))
			{
				// for time or hour format we use just seconds (and no timezone correction between server-time and UTC)
				$value = $no_date ? 3600 * (int) $value['H'] + 60 * (int) $value['i'] :
					adodb_mktime((int) $value['H'],(int) $value['i'],0,$value['m'],$value['d'],$value['Y']);
			}
			else
			{
				for ($n = 0,$str = ''; $n < strlen($data_format); ++$n)
				{
					if (strpos('YmdHis',$c = $data_format[$n]) !== false)
					{
						$str .= sprintf($c=='Y'?'%04d':'%02d',$value[$c]);
					}
					else
					{
						$str .= $c;
					}
				}
				$value = $str;
			}
		}
		else
		{
			$value = '';
		}
		return True;
	}
}