class.forms.php

    }

    function describeSearch($method, $value, $name=false) {
        $name = $name ?: $this->get('name');
        $desc = $this->describeSearchMethod($method);
        switch ($method) {
            case 'set':
            case 'nset':
                return sprintf($desc, $name);
            default:
                 return sprintf($desc, $name, $this->toString($value));
        }
    }

    function addToQuery($query, $name=false) {
        return $query->values($name ?: $this->get('name'));
    }

    /**
     * Similary to to_php() and parse(), except a row from a queryset is
     * passed. The value returned should be what would be retured from
     * parse() or to_php()
     */
    function from_query($row, $name=false) {
        return $row[$name ?: $this->get('name')];
    }

    /**
     * If the field can be used in a quick filter. To be used, it should
     * also implement getQuickFilterChoices() which should return a list of
     * choices to appear in a quick filter drop-down
     */
    function supportsQuickFilter() {
        return false;
    }

    /**
     * Fetch a keyed array of quick filter choices. The keys should be
     * passed later to ::applyQuickFilter() to apply the quick filter to a
     * query. The values should be localized titles for the choices.
     */
    function getQuickFilterChoices() {
        return array();
    }

    /**
     * Apply a quick filter selection of this field to the query. The
     * modified query should be returned. Optionally, the orm path / field
     * name can be passed.
     */
    function applyQuickFilter($query, $choice, $name=false) {
        return $query;
    }

    function getLabel() { return $this->get('label'); }

    function getSortKeys($path) {
        return array($path);
    }

    function getOrmPath($name=false, $query=null) {
        return CustomQueue::getOrmPath($name ?:$this->get('name'), $query);
    }

    function applyOrderBy($query, $reverse=false, $name=false) {
        $col = sprintf('%s%s',
                $reverse ? '-' : '',
                $this->getOrmPath($name, $query));
        return $query->order_by($col);
    }

    /**
     * getImpl
     *
     * Magic method that will return an implementation instance of this
     * field based on the simple text value of the 'type' value of this
     * field instance. The list of registered fields is determined by the
     * global get_dynamic_field_types() function. The data from this model
     * will be used to initialize the returned instance.
     *
     * For instance, if the value of this field is 'text', a TextField
     * instance will be returned.
     */
    function getImpl($parent=null) {
        // Allow registration with ::addFieldTypes and delayed calling
        $type = static::getFieldType($this->get('type'));
        $clazz = $type[1];
        $inst = new $clazz($this->ht);
        $inst->parent = $parent;
        $inst->setForm($this->_form);
        return $inst;
    }

    function __call($what, $args) {
        // XXX: Throw exception if $this->parent is not set
        if (!$this->parent)
            throw new Exception(sprintf(__('%s: Call to undefined function'),
                $what));
        // BEWARE: DynamicFormField has a __call() which will create a new
        //      FormField instance and invoke __call() on it or bounce
        //      immediately back
        return call_user_func_array(
            array($this->parent, $what), $args);
    }

    function getAnswer() { return $this->answer; }
    function setAnswer($ans) { $this->answer = $ans; }

    function setValue($value) {
        $this->reset();
        $this->getWidget()->value = $value;
    }

    /**
     * Fetch a pseudo-random id for this form field. It is used when
     * rendering the widget in the @name attribute emitted in the resulting
     * HTML. The form element is based on the form id, field id and name,
     * and the current user's session id. Therefor, the same form fields
     * will yield differing names for different users. This is used to ward
     * off bot attacks as it makes it very difficult to predict and
     * correlate the form names to the data they represent.
     */
    function getFormName() {
        $default = $this->get('name') ?: $this->get('id');
        if ($this->_form && is_numeric($fid = $this->_form->getFormId()))
            return substr(md5(
                session_id() . '-form-field-id-' . $fid . $default), -14);
        elseif (is_numeric($this->get('id')))
            return substr(md5(
                session_id() . '-field-id-'.$this->get('id')), -16);

        return $default;
    }

    function setForm($form) {
        $this->_form = $form;
    }
    function getForm() {
        return $this->_form;
    }
    /**
     * Returns the data source for this field. If created from a form, the
     * data source from the form is returned. Otherwise, if the request is a
     * POST, then _POST is returned.
     */
    function getSource() {
        if ($this->_form)
            return $this->_form->getSource();
        elseif ($_SERVER['REQUEST_METHOD'] == 'POST')
            return $_POST;
        else
            return array();
    }

    function render($options=array()) {
        $rv = $this->getWidget()->render($options);
        if ($v = $this->get('visibility')) {
            $v->emitJavascript($this);
        }
        return $rv;
    }

    function renderExtras($options=array()) {
        return;
    }

    function getMedia() {
        $widget = $this->getWidget();
        return $widget::$media;
    }

    function getConfigurationOptions() {
        return array();
    }

    /**
     * getConfiguration
     *
     * Loads configuration information from database into hashtable format.
     * Also, the defaults from ::getConfigurationOptions() are integrated
     * into the database-backed options, so that if options have not yet
     * been set or a new option has been added and not saved for this field,
     * the default value will be reflected in the returned configuration.
     */
    function getConfiguration() {
        if (!$this->_config) {
            $this->_config = $this->get('configuration');
            if (is_string($this->_config))
                $this->_config = JsonDataParser::parse($this->_config);
            elseif (!$this->_config)
                $this->_config = array();
            foreach ($this->getConfigurationOptions() as $name=>$field)
                if (!isset($this->_config[$name]))
                    $this->_config[$name] = $field->get('default');
        }
        return $this->_config;
    }

    /**
     * If the [Config] button should be shown to allow for the configuration
     * of this field
     */
    function isConfigurable() {
        return true;
    }

    /**
     * Field type is changeable in the admin interface
     */
    function isChangeable() {
        return true;
    }

    /**
     * Field does not contain data that should be saved to the database. Ie.
     * non data fields like section headers
     */
    function hasData() {
        return true;
    }

    /**
     * Returns true if the field/widget should be rendered as an entire
     * block in the target form.
     */
    function isBlockLevel() {
        return false;
    }

    /**
     * Fields should not be saved with the dynamic data. It is assumed that
     * some static processing will store the data elsewhere.
     */
    function isPresentationOnly() {
        return $this->presentation_only;
    }

    /**
     * Indicates if the field places data in the `value_id` column. This
     * is currently used by the materialized view system
     */
    function hasIdValue() {
        return false;
    }

    /**
     * Indicates if the field has subfields accessible via getSubFields()
     * method. Useful for filter integration. Should connect with
     * getFilterData()
     */
    function hasSubFields() {
        return false;
    }
    function getSubFields() {
        return null;
    }

    function getConfigurationForm($source=null) {
        if (!$this->_cform) {
            $type = static::getFieldType($this->get('type'));
            $clazz = $type[1];
            $T = new $clazz($this->ht);
            $config = $this->getConfiguration();
            $this->_cform = new SimpleForm($T->getConfigurationOptions(), $source);
            if (!$source) {
                foreach ($this->_cform->getFields() as $name=>$f) {
                    if ($config && isset($config[$name]))
                        $f->value = $config[$name];
                    elseif ($f->get('default'))
                        $f->value = $f->get('default');
                }
            }
        }
        return $this->_cform;
    }

    function configure($prop, $value) {
        $this->getConfiguration();
        $this->_config[$prop] = $value;
    }

    function getWidget($widgetClass=false) {
        if (!static::$widget)
            throw new Exception(__('Widget not defined for this field'));
        if (!isset($this->_widget)) {
            $wc = $widgetClass ?: $this->get('widget') ?: static::$widget;
            $this->_widget = new $wc($this);
            $this->_widget->parseValue();
        }
        return $this->_widget;
    }

    function getSelectName() {
        $name = $this->get('name') ?: 'field_'.$this->get('id');
        if ($this->hasIdValue())
            $name .= '_id';

        return $name;
    }

    function getTranslateTag($subtag) {
        return _H(sprintf('field.%s.%s%s', $subtag, $this->get('id'),
            $this->get('form_id') ? '' : '*internal*'));
    }

    function getLocal($subtag, $default=false) {
        $tag = $this->getTranslateTag($subtag);
        $T = CustomDataTranslation::translate($tag);
        return $T != $tag ? $T : ($default ?: $this->get($subtag));
    }

    function getEditForm($source=null) {

        $fields = array(
                'field' => $this,
                'comments' => new TextareaField(array(
                        'id' => 2,
                        'label'=> '',
                        'required' => false,
                        'default' => '',
                        'configuration' => array(
                            'html' => true,
                            'size' => 'small',
                            'placeholder' => __('Optional reason for the update'),
                            )
                        ))
                );

        return new SimpleForm($fields, $source);
    }

    function getChanges() {
        $a = $this->to_database($this->getClean());
        $b = $this->to_database($this->answer ? $this->answer->getValue() : $this->get('default'));
        return ($a != $b) ? array($b, $a) : false;
    }


    function save() {

        if (!($changes=$this->getChanges()))
            return true;

        if (!($a = $this->answer))
            return false;

        $val = $changes[1];
        if (is_array($val)) {
            $a->set('value', $val[0]);
            $a->set('value_id', $val[1]);
        } else {
            $a->set('value', $val);
        }

        if (!$a->save(true))
            return false;

        return $this->parent->save();
    }


    static function init($config) {
        return new Static($config);
    }
}

class TextboxField extends FormField {
    static $widget = 'TextboxWidget';

    function getConfigurationOptions() {
        return array(
            'size'  =>  new TextboxField(array(
                'id'=>1, 'label'=>__('Size'), 'required'=>false, 'default'=>16,
                    'validator' => 'number')),
            'length' => new TextboxField(array(
                'id'=>2, 'label'=>__('Max Length'), 'required'=>false, 'default'=>30,
                    'validator' => 'number')),
            'validator' => new ChoiceField(array(
                'id'=>3, 'label'=>__('Validator'), 'required'=>false, 'default'=>'',
                'choices' => array('phone'=>__('Phone Number'),'email'=>__('Email Address'),
                    'ip'=>__('IP Address'), 'number'=>__('Number'),
                    'regex'=>__('Custom (Regular Expression)'), ''=>__('None')))),
            'regex' => new TextboxField(array(
                'id'=>6, 'label'=>__('Regular Expression'), 'required'=>true,
                'configuration'=>array('size'=>40, 'length'=>100),
                'visibility' => new VisibilityConstraint(
                    new Q(array('validator__eq'=>'regex')),
                    VisibilityConstraint::HIDDEN
                ),
                'cleaners' => function ($self, $value) {
                    $wrapped = "/".$value."/iu";
                    if (false === @preg_match($value, ' ')
                            && false !== @preg_match($wrapped, ' ')) {
                        $value = $wrapped;
                    }
                    if ($value == '//iu')
                        return '';

                    return $value;
                },
                'validators' => function($self, $v) {
                    if (false === @preg_match($v, ' '))
                        $self->addError(__('Cannot compile this regular expression'));
                })),
            'validator-error' => new TextboxField(array(
                'id'=>4, 'label'=>__('Validation Error'), 'default'=>'',
                'configuration'=>array('size'=>40, 'length'=>60,
                    'translatable'=>$this->getTranslateTag('validator-error')
                ),
                'hint'=>__('Message shown to user if the input does not match the validator'))),
            'placeholder' => new TextboxField(array(
                'id'=>5, 'label'=>__('Placeholder'), 'required'=>false, 'default'=>'',
                'hint'=>__('Text shown in before any input from the user'),
                'configuration'=>array('size'=>40, 'length'=>40,
                    'translatable'=>$this->getTranslateTag('placeholder')
                ),
            )),
        );
    }

    function validateEntry($value) {
        parent::validateEntry($value);
        $config = $this->getConfiguration();
        $validators = array(
            '' =>       null,
            'email' =>  array(array('Validator', 'is_valid_email'),
                __('Enter a valid email address')),
            'phone' =>  array(array('Validator', 'is_phone'),
                __('Enter a valid phone number')),
            'ip' =>     array(array('Validator', 'is_ip'),
                __('Enter a valid IP address')),
            'number' => array('is_numeric', __('Enter a number')),
            'regex' => array(
                function($v) use ($config) {
                    $regex = $config['regex'];
                    return @preg_match($regex, $v);
                }, __('Value does not match required pattern')
            ),
        );
        // Support configuration forms, as well as GUI-based form fields
        $valid = $this->get('validator');
        if (!$valid) {
            $valid = $config['validator'];
        }
        if (!$value || !isset($validators[$valid]))
            return;
        $func = $validators[$valid];
        $error = $func[1];
        if ($config['validator-error'])
            $error = $this->getLocal('validator-error', $config['validator-error']);
        if (is_array($func) && is_callable($func[0]))
            if (!call_user_func($func[0], $value))
                $this->_errors[] = $error;
    }

    function parse($value) {
        return Format::striptags($value);
    }
}

class PasswordField extends TextboxField {
    static $widget = 'PasswordWidget';

    function parse($value) {
        // Don't trim the value
        return $value;
    }

    function to_database($value) {
        // If not set in UI, don't save the empty value
        if (!$value)
            throw new FieldUnchanged();
        return Crypto::encrypt($value, SECRET_SALT, 'pwfield');
    }

    function to_php($value) {
        return Crypto::decrypt($value, SECRET_SALT, 'pwfield');
    }
}

class TextareaField extends FormField {
    static $widget = 'TextareaWidget';

    function getConfigurationOptions() {
        return array(
            'cols'  =>  new TextboxField(array(
                'id'=>1, 'label'=>__('Width').' '.__('(chars)'), 'required'=>true, 'default'=>40)),
            'rows'  =>  new TextboxField(array(
                'id'=>2, 'label'=>__('Height').' '.__('(rows)'), 'required'=>false, 'default'=>4)),
            'length' => new TextboxField(array(
                'id'=>3, 'label'=>__('Max Length'), 'required'=>false, 'default'=>0)),
            'html' => new BooleanField(array(
                'id'=>4, 'label'=>__('HTML'), 'required'=>false, 'default'=>true,
                'configuration'=>array('desc'=>__('Allow HTML input in this box')))),
            'placeholder' => new TextboxField(array(
                'id'=>5, 'label'=>__('Placeholder'), 'required'=>false, 'default'=>'',
                'hint'=>__('Text shown in before any input from the user'),
                'configuration'=>array('size'=>40, 'length'=>40,
                    'translatable'=>$this->getTranslateTag('placeholder')),
            )),
        );
    }

    function validateEntry($value) {
        parent::validateEntry($value);
        $config = $this->getConfiguration();
        $validators = array(
            '' =>       null,
            'choices' => array(
                function($val) {
                    $val = str_replace('"', '', JsonDataEncoder::encode($val));
                    $regex = "/^(?! )[A-z0-9 _-]+:{1}[A-z0-9 _-]+$/";
                    foreach (explode('\r\n', $val) as $v) {
                        if (!preg_match($regex, $v))
                            return false;
                    }
                    return true;
                }, __('Each choice requires a key and has to be on a new line. (eg. key:value)')
            ),
        );
        // Support configuration forms, as well as GUI-based form fields
        $valid = $this->get('validator');
        if (!$valid) {
            $valid = $config['validator'];
        }
        if (!$value || !isset($validators[$valid]))
            return;
        $func = $validators[$valid];
        $error = $func[1];
        if ($config['validator-error'])
            $error = $this->getLocal('validator-error', $config['validator-error']);
        if (is_array($func) && is_callable($func[0]))
            if (!call_user_func($func[0], $value))
                $this->_errors[] = $error;
    }

    function display($value) {
        $config = $this->getConfiguration();
        if ($config['html'])
            return Format::safe_html($value);
        else
            return nl2br(Format::htmlchars($value));
    }

    function searchable($value) {
        $body = new HtmlThreadEntryBody($value);
        return $body->getSearchable();
    }

    function export($value) {
        return (!$value) ? $value : Format::html2text($value);
    }

    function parse($value) {
        $config = $this->getConfiguration();
        if ($config['html'])
            return Format::sanitize($value);
        else
            return $value;
    }

}

class PhoneField extends FormField {
    static $widget = 'PhoneNumberWidget';

    function getConfigurationOptions() {
        return array(
            'ext' => new BooleanField(array(
                'label'=>__('Extension'), 'default'=>true,
                'configuration'=>array(
                    'desc'=>__('Add a separate field for the extension'),
                ),
            )),
            'digits' => new TextboxField(array(
                'label'=>__('Minimum length'), 'default'=>7,
                'hint'=>__('Fewest digits allowed in a valid phone number'),
                'configuration'=>array('validator'=>'number', 'size'=>5),
            )),
            'format' => new ChoiceField(array(
                'label'=>__('Display format'), 'default'=>'us',
                'choices'=>array(''=>'-- '.__('Unformatted').' --',
                    'us'=>__('United States')),
            )),
        );
    }

    function validateEntry($value) {
        parent::validateEntry($value);
        $config = $this->getConfiguration();
        # Run validator against $this->value for email type
        list($phone, $ext) = explode("X", $value, 2);
        if ($phone && (
                !is_numeric($phone) ||
                strlen($phone) < $config['digits']))
            $this->_errors[] = __("Enter a valid phone number");
        if ($ext && $config['ext']) {
            if (!is_numeric($ext))
                $this->_errors[] = __("Enter a valid phone extension");
            elseif (!$phone)
                $this->_errors[] = __("Enter a phone number for the extension");
        }
    }

    function parse($value) {
        // NOTE: Value may have a legitimate 'X' to separate the number and
        // extension parts. Don't remove the 'X'
        $val = preg_replace('/[^\dX]/', '', $value);
        // Pass completely-incorrect string for validation error
        return $val ?: $value;
    }

    function toString($value) {
        $config = $this->getConfiguration();
        list($phone, $ext) = explode("X", $value, 2);
        switch ($config['format']) {
        case 'us':
            $phone = Format::phone($phone);
            break;
        }
        if ($ext)
            $phone.=" x$ext";
        return $phone;
    }
}

class BooleanField extends FormField {
    static $widget = 'CheckboxWidget';

    function getConfigurationOptions() {
        return array(
            'desc' => new TextareaField(array(
                'id'=>1, 'label'=>__('Description'), 'required'=>false, 'default'=>'',
                'hint'=>__('Text shown inline with the widget'),
                'configuration'=>array('rows'=>2)))
        );
    }

    function to_database($value) {
        return ($value) ? '1' : '0';
    }

    function parse($value) {
        return $this->to_php($value);
    }
    function to_php($value) {
        return $value ? true : false;
    }

    function toString($value) {
        return ($value) ? __('Yes') : __('No');
    }

    function getSearchMethods() {
        return array(
            'set' =>        __('checked'),
            'nset' =>    __('unchecked'),
        );
    }

    function describeSearchMethod($method) {

        $methods = $this->get('descsearchmethods');
        if (isset($methods[$method]))
            return $methods[$method];

        return parent::describeSearchMethod($method);
    }

    function getSearchMethodWidgets() {
        return array(
            'set' => null,
            'nset' => null,
        );
    }

    function getSearchQ($method, $value, $name=false) {
        $name = $name ?: $this->get('name');
        switch ($method) {
        case 'set':
            return new Q(array($name => '1'));
        case 'nset':
            return new Q(array($name => '0'));
        default:
            return parent::getSearchQ($method, $value, $name);
        }
    }

    function supportsQuickFilter() {
        return true;
    }

    function getQuickFilterChoices() {
        return array(
            true => __('Checked'),
            false => __('Not Checked'),
        );
    }

    function applyQuickFilter($query, $qf_value, $name=false) {
        return $query->filter(array(
            $name ?: $this->get('name') => (int) $qf_value,
        ));
    }
}

class ChoiceField extends FormField {
    static $widget = 'ChoicesWidget';
    var $_choices;

    function getConfigurationOptions() {
        return array(
            'choices'  =>  new TextareaField(array(
                'id'=>1, 'label'=>__('Choices'), 'required'=>false, 'default'=>'',
                'hint'=>__('List choices, one per line. To protect against spelling changes, specify key:value names to preserve entries if the list item names change.</br><b>Note:</b> If you have more than two choices, use a List instead.'),
                'validator'=>'choices',
                'configuration'=>array('html'=>false)
            )),
            'default' => new TextboxField(array(
                'id'=>3, 'label'=>__('Default'), 'required'=>false, 'default'=>'',
                'hint'=>__('(Enter a key). Value selected from the list initially'),
                'configuration'=>array('size'=>20, 'length'=>40),
            )),
            'prompt' => new TextboxField(array(
                'id'=>2, 'label'=>__('Prompt'), 'required'=>false, 'default'=>'',
                'hint'=>__('Leading text shown before a value is selected'),
                'configuration'=>array('size'=>40, 'length'=>40,
                    'translatable'=>$this->getTranslateTag('prompt'),
                ),
            )),
            'multiselect' => new BooleanField(array(
                'id'=>1, 'label'=>'Multiselect', 'required'=>false, 'default'=>false,
                'configuration'=>array(
                    'desc'=>'Allow multiple selections')
            )),
        );
    }

    function parse($value) {
        return $this->to_php($value ?: null);
    }

    function to_database($value) {
        if (!is_array($value)) {
            $choices = $this->getChoices();
            if (isset($choices[$value]))
                $value = array($value => $choices[$value]);
        }
        if (is_array($value))
            $value = JsonDataEncoder::encode($value);

        return $value;
    }

    function to_php($value) {
        if (is_string($value))
            $value = JsonDataParser::parse($value) ?: $value;

        // CDATA table may be built with comma-separated key,value,key,value
        if (is_string($value) && strpos($value, ',')) {
            $values = array();
            $choices = $this->getChoices();
            $vals = explode(',', $value);
            foreach ($vals as $V) {
                if (isset($choices[$V]))
                    $values[$V] = $choices[$V];
            }
            if (array_filter($values))
                $value = $values;
            elseif($vals)
                list($value) = $vals;

        }
        $config = $this->getConfiguration();
        if (!$config['multiselect'] && is_array($value) && count($value) < 2) {
            reset($value);
            $value = key($value);
        }
        return $value;
    }

    function toString($value) {
        if (!is_array($value))
            $value = $this->getChoice($value);
        if (is_array($value))
            return implode(', ', $value);
        return (string) $value;
    }

    function getKeys($value) {
        if (!is_array($value))
            $value = $this->getChoice($value);
        if (is_array($value))
            return implode(', ', array_keys($value));
        return (string) $value;
    }

    function whatChanged($before, $after) {
        $B = (array) $before;
        $A = (array) $after;
        $added = array_diff($A, $B);
        $deleted = array_diff($B, $A);
        $added = array_map(array($this, 'display'), $added);
        $deleted = array_map(array($this, 'display'), $deleted);
        $added = array_filter($added);
        $deleted = array_filter($deleted);

        if ($added && $deleted) {
            $desc = sprintf(
                __('added <strong>%1$s</strong> and removed <strong>%2$s</strong>'),
                implode(', ', $added), implode(', ', $deleted));
        }
        elseif ($added) {
            $desc = sprintf(
                __('added <strong>%1$s</strong>'),
                implode(', ', $added));
        }
        elseif ($deleted) {
            $desc = sprintf(
                __('removed <strong>%1$s</strong>'),
                implode(', ', $deleted));
        }
        else {
            $desc = sprintf(
                __('changed from <strong>%1$s</strong> to <strong>%2$s</strong>'),
                $this->display($before), $this->display($after));
        }
        return $desc;
    }

    /*
     Return criteria to which the choice should be filtered by
     */
    function getCriteria() {
        $config = $this->getConfiguration();
        $criteria = array();
        if (isset($config['criteria']))
            $criteria = $config['criteria'];

        return $criteria;
    }

    function getChoice($value) {

        $choices = $this->getChoices();
        $selection = array();
        if ($value && is_array($value)) {
            $selection = $value;
        } elseif (isset($choices[$value]))
            $selection[$value] = $choices[$value];
        elseif (($v=$this->get('default')) && isset($choices[$v]))
            $selection[$v] = $choices[$v];

        return $selection;
    }

    function getChoices($verbose=false) {
        if ($this->_choices === null || $verbose) {
            // Allow choices to be set in this->ht (for configurationOptions)
            $this->_choices = $this->get('choices');
            if (!$this->_choices) {
                $this->_choices = array();
                $config = $this->getConfiguration();
                $choices = explode("\n", $config['choices']);
                foreach ($choices as $choice) {
                    // Allow choices to be key: value
                    list($key, $val) = explode(':', $choice);
                    if ($val == null)
                        $val = $key;
                    $this->_choices[trim($key)] = trim($val);
                }
                // Add old selections if nolonger available
                // This is necessary so choices made previously can be
                // retained
                $values = ($a=$this->getAnswer()) ? $a->getValue() : array();
                if ($values && is_array($values)) {
                    foreach ($values as $k => $v) {
                        if (!isset($this->_choices[$k])) {
                            if ($verbose) $v .= ' (retired)';
                            $this->_choices[$k] = $v;
                        }
                    }
                }
            }
        }
        return $this->_choices;
    }

    function lookupChoice($value) {
        return null;
    }

    function getSearchMethods() {
        return array(
            'set' =>        __('has a value'),
            'nset' =>     __('does not have a value'),
            'includes' =>   __('includes'),
            '!includes' =>  __('does not include'),
        );
    }

    function getSearchMethodWidgets() {
        return array(
            'set' => null,
            'nset' => null,
            'includes' => array('ChoiceField', array(
                'choices' => $this->getChoices(),
                'configuration' => array('multiselect' => true),
            )),
            '!includes' => array('ChoiceField', array(
                'choices' => $this->getChoices(),
                'configuration' => array('multiselect' => true),
            )),
        );
    }

    function getSearchQ($method, $value, $name=false) {
        $name = $name ?: $this->get('name');
        $val = $value;
        if ($value && is_array($value))
            $val = '"?'.implode('("|,|$)|"?', array_keys($value)).'("|,|$)';
        switch ($method) {
        case '!includes':
            return Q::not(array("{$name}__regex" => $val));
        case 'includes':
            return new Q(array("{$name}__regex" => $val));
        default:
            return parent::getSearchQ($method, $value, $name);
        }
    }

    function describeSearchMethod($method) {
        switch ($method) {
        case 'includes':
            return __('%s includes %s' /* includes -> if a list includes a selection */);
        case '!includes':
            return __('%s does not include %s' /* includes -> if a list includes a selection */);
        default:
            return parent::describeSearchMethod($method);
        }
    }

    function supportsQuickFilter() {
        return true;
    }

    function getQuickFilterChoices() {
        return $this->getChoices();
    }

    function applyQuickFilter($query, $qf_value, $name=false) {
        return $query->filter(array(
            $name ?: $this->get('name') => $qf_value,
        ));
    }
}

class DatetimeField extends FormField {
    static $widget = 'DatetimePickerWidget';

    var $min = null;
    var $max = null;

    static function intervals($count=2, $i='') {
        $intervals = array(
            'i' => _N('minute', 'minutes', $count),
            'h' => _N('hour', 'hours', $count),
            'd' => _N('day','days', $count),
            'w' => _N('week', 'weeks', $count),
            'm' => _N('month', 'months', $count),
        );

        return $i ? $intervals[$i] : $intervals;
    }

    // Get php DatateTime object of the field  - null if value is empty
    function getDateTime($value=null) {
        return Format::parseDateTime($value ?: $this->value);
    }

    // Get effective timezone for the field
    function getTimeZone() {
        global $cfg;

        $config = $this->getConfiguration();
        $timezone = new DateTimeZone($config['timezone'] ?:
                $cfg->getTimezone());

        return $timezone;
    }

    function getMinDateTime() {

        if (!isset($this->min)) {
            $config = $this->getConfiguration();
            $this->min = $config['min']
                ? Format::parseDateTime($config['min']) : false;
        }

        return $this->min;