lib/form/autocomplete.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  * autocomplete type form element
  20  *
  21  * Contains HTML class for a autocomplete type element
  22  *
  23  * @package   core_form
  24  * @copyright 2015 Damyon Wiese <damyon@moodle.com>
  25  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  26  */
  27
  28 global $CFG;
  29
  30 require_once($CFG->libdir . '/form/select.php');
  31
  32 /**
  33  * Autocomplete as you type form element
  34  *
  35  * HTML class for a autocomplete type element
  36  *
  37  * @package   core_form
  38  * @copyright 2015 Damyon Wiese <damyon@moodle.com>
  39  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  40  */
  41 class MoodleQuickForm_autocomplete extends MoodleQuickForm_select {
  42
  43     /** @var boolean $tags Should we allow typing new entries to the field? */
  44     protected $tags = false;
  45     /** @var string $ajax Name of an AMD module to send/process ajax requests. */
  46     protected $ajax = '';
  47     /** @var string $placeholder Placeholder text for an empty list. */
  48     protected $placeholder = '';
  49     /** @var bool $casesensitive Whether the search has to be case-sensitive. */
  50     protected $casesensitive = false;
  51     /** @var bool $showsuggestions Show suggestions by default - but this can be turned off. */
  52     protected $showsuggestions = true;
  53     /** @var string $noselectionstring String that is shown when there are no selections. */
  54     protected $noselectionstring = '';
  55     /** @var callable|null Function to call (with existing value) to render it to HTML */
  56     protected $valuehtmlcallback = null;
  57
  58     /**
  59      * constructor
  60      *
  61      * @param string $elementName Select name attribute
  62      * @param mixed $elementLabel Label(s) for the select
  63      * @param mixed $options Data to be used to populate options
  64      * @param mixed $attributes Either a typical HTML attribute string or an associative array. Special options
  65      *                          "tags", "placeholder", "ajax", "multiple", "casesensitive" are supported.
  66      */
  67     public function __construct($elementName=null, $elementLabel=null, $options=null, $attributes=null) {
  68         // Even if the constructor gets called twice we do not really want 2x options (crazy forms!).
  69         $this->_options = array();
  70         if ($attributes === null) {
  71             $attributes = array();
  72         }
  73         if (isset($attributes['tags'])) {
  74             $this->tags = $attributes['tags'];
  75             unset($attributes['tags']);
  76         }
  77         if (isset($attributes['showsuggestions'])) {
  78             $this->showsuggestions = $attributes['showsuggestions'];
  79             unset($attributes['showsuggestions']);
  80         }
  81         $this->placeholder = get_string('search');
  82         if (isset($attributes['placeholder'])) {
  83             $this->placeholder = $attributes['placeholder'];
  84             unset($attributes['placeholder']);
  85         }
  86         $this->noselectionstring = get_string('noselection', 'form');
  87         if (isset($attributes['noselectionstring'])) {
  88             $this->noselectionstring = $attributes['noselectionstring'];
  89             unset($attributes['noselectionstring']);
  90         }
  91
  92         if (isset($attributes['ajax'])) {
  93             $this->ajax = $attributes['ajax'];
  94             unset($attributes['ajax']);
  95         }
  96         if (isset($attributes['casesensitive'])) {
  97             $this->casesensitive = $attributes['casesensitive'] ? true : false;
  98             unset($attributes['casesensitive']);
  99         }
 100         if (isset($attributes['valuehtmlcallback'])) {
 101             $this->valuehtmlcallback = $attributes['valuehtmlcallback'];
 102             unset($attributes['valuehtmlcallback']);
 103         }
 104         parent::__construct($elementName, $elementLabel, $options, $attributes);
 105
 106         $this->_type = 'autocomplete';
 107     }
 108
 109     /**
 110      * Old syntax of class constructor. Deprecated in PHP7.
 111      *
 112      * @deprecated since Moodle 3.1
 113      */
 114     public function MoodleQuickForm_autocomplete($elementName=null, $elementLabel=null, $options=null, $attributes=null) {
 115         debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
 116         self::__construct($elementName, $elementLabel, $options, $attributes);
 117     }
 118
 119     /**
 120      * Returns HTML for select form element.
 121      *
 122      * @return string
 123      */
 124     function toHtml(){
 125         global $PAGE;
 126
 127         // Enhance the select with javascript.
 128         $this->_generateId();
 129         $id = $this->getAttribute('id');
 130
 131         if (!$this->isFrozen()) {
 132             $PAGE->requires->js_call_amd('core/form-autocomplete', 'enhance', $params = array('#' . $id, $this->tags, $this->ajax,
 133                 $this->placeholder, $this->casesensitive, $this->showsuggestions, $this->noselectionstring));
 134         }
 135
 136         $html = parent::toHTML();
 137
 138         // Hacky bodge to add in the HTML code to the option tag. There is a nicer
 139         // version of this code in the new template version (see export_for_template).
 140         if ($this->valuehtmlcallback) {
 141             $html = preg_replace_callback('~value="([^"]+)"~', function($matches) {
 142                 $value = html_entity_decode($matches[1], ENT_COMPAT);
 143                 $htmlvalue = call_user_func($this->valuehtmlcallback, $value);
 144                 if ($htmlvalue !== false) {
 145                     return $matches[0] . ' data-html="' . s($htmlvalue) . '"';
 146                 } else {
 147                     return $matches[0];
 148                 }
 149             }, $html);
 150         }
 151
 152         return $html;
 153     }
 154
 155     /**
 156      * Search the current list of options to see if there are any options with this value.
 157      * @param  string $value to search
 158      * @return boolean
 159      */
 160     function optionExists($value) {
 161         foreach ($this->_options as $option) {
 162             if (isset($option['attr']['value']) && ($option['attr']['value'] == $value)) {
 163                 return true;
 164             }
 165         }
 166         return false;
 167     }
 168
 169     /**
 170      * Set the value of this element. If values can be added or are unknown, we will
 171      * make sure they exist in the options array.
 172      * @param  mixed string|array $value The value to set.
 173      * @return boolean
 174      */
 175     function setValue($value) {
 176         $values = (array) $value;
 177         foreach ($values as $onevalue) {
 178             if (($this->tags || $this->ajax) &&
 179                     (!$this->optionExists($onevalue)) &&
 180                     ($onevalue !== '_qf__force_multiselect_submission')) {
 181                 $this->addOption($onevalue, $onevalue);
 182             }
 183         }
 184         return parent::setValue($value);
 185     }
 186
 187     /**
 188      * Returns a 'safe' element's value
 189      *
 190      * @param  array   array of submitted values to search
 191      * @param  bool    whether to return the value as associative array
 192      * @access public
 193      * @return mixed
 194      */
 195     function exportValue(&$submitValues, $assoc = false) {
 196         if ($this->ajax || $this->tags) {
 197             // When this was an ajax request, we do not know the allowed list of values.
 198             $value = $this->_findValue($submitValues);
 199             if (null === $value) {
 200                 $value = $this->getValue();
 201             }
 202             // Quickforms inserts a duplicate element in the form with
 203             // this value so that a value is always submitted for this form element.
 204             // Normally this is cleaned as a side effect of it not being a valid option,
 205             // but in this case we need to detect and skip it manually.
 206             if ($value === '_qf__force_multiselect_submission' || $value === null) {
 207                 $value = $this->getMultiple() ? [] : '';
 208             }
 209             return $this->_prepareValue($value, $assoc);
 210         } else {
 211             return parent::exportValue($submitValues, $assoc);
 212         }
 213     }
 214
 215     /**
 216      * Called by HTML_QuickForm whenever form event is made on this element
 217      *
 218      * @param string $event Name of event
 219      * @param mixed $arg event arguments
 220      * @param object $caller calling object
 221      * @return bool
 222      */
 223     function onQuickFormEvent($event, $arg, &$caller)
 224     {
 225         switch ($event) {
 226             case 'createElement':
 227                 $caller->setType($arg[0], PARAM_TAGLIST);
 228                 break;
 229         }
 230         return parent::onQuickFormEvent($event, $arg, $caller);
 231     }
 232
 233     public function export_for_template(renderer_base $output) {
 234         $this->_generateId();
 235         $context = parent::export_for_template($output);
 236         $context['tags'] = !empty($this->tags);
 237         $context['ajax'] = $this->ajax;
 238         $context['placeholder'] = $this->placeholder;
 239         $context['casesensitive'] = !empty($this->casesensitive);
 240         $context['showsuggestions'] = !empty($this->showsuggestions);
 241         $context['noselectionstring'] = $this->noselectionstring;
 242         if ($this->valuehtmlcallback) {
 243             foreach ($context['options'] as &$option) {
 244                 $value = $option['value'];
 245                 $html = call_user_func($this->valuehtmlcallback, $value);
 246                 if ($html !== false) {
 247                     $option['html'] = $html;
 248                     if ($this->isFrozen()) {
 249                         $option['text'] = $html;
 250                     }
 251                 }
 252             }
 253         }
 254
 255         return $context;
 256     }
 257 }