lib/form/duration.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 /**
  19  * Duration form element
  20  *
  21  * Contains class to create length of time for element.
  22  *
  23  * @package   core_form
  24  * @copyright 2009 Tim Hunt
  25  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 global $CFG;
  29 require_once($CFG->libdir . '/form/group.php');
  30 require_once($CFG->libdir . '/formslib.php');
  31 require_once($CFG->libdir . '/form/text.php');
  32
  33 /**
  34  * Duration element
  35  *
  36  * HTML class for a length of time. For example, 30 minutes of 4 days. The
  37  * values returned to PHP is the duration in seconds.
  38  *
  39  * @package   core_form
  40  * @category  form
  41  * @copyright 2009 Tim Hunt
  42  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  43  */
  44 class MoodleQuickForm_duration extends MoodleQuickForm_group {
  45    /**
  46     * Control the fieldnames for form elements
  47     * optional => if true, show a checkbox beside the element to turn it on (or off)
  48     * @var array
  49     */
  50    protected $_options = array('optional' => false, 'defaultunit' => 60);
  51
  52    /** @var array associative array of time units (days, hours, minutes, seconds) */
  53    private $_units = null;
  54
  55    /**
  56     * constructor
  57     *
  58     * @param string $elementName Element's name
  59     * @param mixed $elementLabel Label(s) for an element
  60     * @param array $options Options to control the element's display. Recognised values are
  61     *              'optional' => true/false - whether to display an 'enabled' checkbox next to the element.
  62     *              'defaultunit' => 1|60|3600|86400|604800 - the default unit to display when the time is blank.
  63     *              If not specified, minutes is used.
  64     * @param mixed $attributes Either a typical HTML attribute string or an associative array
  65     */
  66     function MoodleQuickForm_duration($elementName = null, $elementLabel = null, $options = array(), $attributes = null) {
  67         $this->HTML_QuickForm_element($elementName, $elementLabel, $attributes);
  68         $this->_persistantFreeze = true;
  69         $this->_appendName = true;
  70         $this->_type = 'duration';
  71
  72         // Set the options, do not bother setting bogus ones
  73         if (!is_array($options)) {
  74             $options = array();
  75         }
  76         $this->_options['optional'] = !empty($options['optional']);
  77         if (isset($options['defaultunit'])) {
  78             if (!array_key_exists($options['defaultunit'], $this->get_units())) {
  79                 throw new coding_exception($options['defaultunit'] .
  80                         ' is not a recognised unit in MoodleQuickForm_duration.');
  81             }
  82             $this->_options['defaultunit'] = $options['defaultunit'];
  83         }
  84     }
  85
  86     /**
  87      * Returns time associative array of unit length.
  88      *
  89      * @return array unit length in seconds => string unit name.
  90      */
  91     public function get_units() {
  92         if (is_null($this->_units)) {
  93             $this->_units = array(
  94                 604800 => get_string('weeks'),
  95                 86400 => get_string('days'),
  96                 3600 => get_string('hours'),
  97                 60 => get_string('minutes'),
  98                 1 => get_string('seconds'),
  99             );
 100         }
 101         return $this->_units;
 102     }
 103
 104     /**
 105      * Converts seconds to the best possible time unit. for example
 106      * 1800 -> array(30, 60) = 30 minutes.
 107      *
 108      * @param int $seconds an amout of time in seconds.
 109      * @return array associative array ($number => $unit)
 110      */
 111     public function seconds_to_unit($seconds) {
 112         if ($seconds == 0) {
 113             return array(0, $this->_options['defaultunit']);
 114         }
 115         foreach ($this->get_units() as $unit => $notused) {
 116             if (fmod($seconds, $unit) == 0) {
 117                 return array($seconds / $unit, $unit);
 118             }
 119         }
 120         return array($seconds, 1);
 121     }
 122
 123     /**
 124      * Override of standard quickforms method to create this element.
 125      */
 126     function _createElements() {
 127         $attributes = $this->getAttributes();
 128         if (is_null($attributes)) {
 129             $attributes = array();
 130         }
 131         if (!isset($attributes['size'])) {
 132             $attributes['size'] = 3;
 133         }
 134         $this->_elements = array();
 135         // E_STRICT creating elements without forms is nasty because it internally uses $this
 136         $this->_elements[] = @MoodleQuickForm::createElement('text', 'number', get_string('time', 'form'), $attributes, true);
 137         unset($attributes['size']);
 138         $this->_elements[] = @MoodleQuickForm::createElement('select', 'timeunit', get_string('timeunit', 'form'), $this->get_units(), $attributes, true);
 139         // If optional we add a checkbox which the user can use to turn if on
 140         if($this->_options['optional']) {
 141             $this->_elements[] = @MoodleQuickForm::createElement('checkbox', 'enabled', null, get_string('enable'), $this->getAttributes(), true);
 142         }
 143         foreach ($this->_elements as $element){
 144             if (method_exists($element, 'setHiddenLabel')){
 145                 $element->setHiddenLabel(true);
 146             }
 147         }
 148     }
 149
 150     /**
 151      * Called by HTML_QuickForm whenever form event is made on this element
 152      *
 153      * @param string $event Name of event
 154      * @param mixed $arg event arguments
 155      * @param object $caller calling object
 156      * @return bool
 157      */
 158     function onQuickFormEvent($event, $arg, &$caller) {
 159         switch ($event) {
 160             case 'updateValue':
 161                 // constant values override both default and submitted ones
 162                 // default values are overriden by submitted
 163                 $value = $this->_findValue($caller->_constantValues);
 164                 if (null === $value) {
 165                     // if no boxes were checked, then there is no value in the array
 166                     // yet we don't want to display default value in this case
 167                     if ($caller->isSubmitted()) {
 168                         $value = $this->_findValue($caller->_submitValues);
 169                     } else {
 170                         $value = $this->_findValue($caller->_defaultValues);
 171                     }
 172                 }
 173                 if (!is_array($value)) {
 174                     list($number, $unit) = $this->seconds_to_unit($value);
 175                     $value = array('number' => $number, 'timeunit' => $unit);
 176                     // If optional, default to off, unless a date was provided
 177                     if ($this->_options['optional']) {
 178                         $value['enabled'] = $number != 0;
 179                     }
 180                 } else {
 181                     $value['enabled'] = isset($value['enabled']);
 182                 }
 183                 if (null !== $value){
 184                     $this->setValue($value);
 185                 }
 186                 break;
 187
 188             case 'createElement':
 189                 if ($arg[2]['optional']) {
 190                     $caller->disabledIf($arg[0], $arg[0] . '[enabled]');
 191                 }
 192                 $caller->setType($arg[0] . '[number]', PARAM_FLOAT);
 193                 return parent::onQuickFormEvent($event, $arg, $caller);
 194                 break;
 195
 196             default:
 197                 return parent::onQuickFormEvent($event, $arg, $caller);
 198         }
 199     }
 200
 201     /**
 202      * Returns HTML for advchecbox form element.
 203      *
 204      * @return string
 205      */
 206     function toHtml() {
 207         include_once('HTML/QuickForm/Renderer/Default.php');
 208         $renderer = new HTML_QuickForm_Renderer_Default();
 209         $renderer->setElementTemplate('{element}');
 210         parent::accept($renderer);
 211         return $renderer->toHtml();
 212     }
 213
 214     /**
 215      * Accepts a renderer
 216      *
 217      * @param HTML_QuickForm_Renderer $renderer An HTML_QuickForm_Renderer object
 218      * @param bool $required Whether a group is required
 219      * @param string $error An error message associated with a group
 220      */
 221     function accept(&$renderer, $required = false, $error = null) {
 222         $renderer->renderElement($this, $required, $error);
 223     }
 224
 225     /**
 226      * Output a timestamp. Give it the name of the group.
 227      * Override of standard quickforms method.
 228      *
 229      * @param  array $submitValues
 230      * @param  bool  $notused Not used.
 231      * @return array field name => value. The value is the time interval in seconds.
 232      */
 233     function exportValue(&$submitValues, $notused = false) {
 234         // Get the values from all the child elements.
 235         $valuearray = array();
 236         foreach ($this->_elements as $element) {
 237             $thisexport = $element->exportValue($submitValues[$this->getName()], true);
 238             if (!is_null($thisexport)) {
 239                 $valuearray += $thisexport;
 240             }
 241         }
 242
 243         // Convert the value to an integer number of seconds.
 244         if (empty($valuearray)) {
 245             return null;
 246         }
 247         if ($this->_options['optional'] && empty($valuearray['enabled'])) {
 248             return array($this->getName() => 0);
 249         }
 250         return array($this->getName() => $valuearray['number'] * $valuearray['timeunit']);
 251     }
 252 }