class.dynamic_forms.php

            return array($item->value, $item->id);
        return null;
    }

    function toString($item) {
        return ($item instanceof DynamicListItem)
            ? $item->toString() : (string) $item;
    }

    function validateEntry($item) {
        $config = $this->getConfiguration();
        parent::validateEntry($item);
        if ($item && !$item instanceof DynamicListItem)
            $this->_errors[] = 'Select a value from the list';
        elseif ($item && $config['typeahead']
                && $this->getWidget()->getEnteredValue() != $item->get('value'))
            $this->_errors[] = 'Select a value from the list';
    }

    function getConfigurationOptions() {
        return array(
            'typeahead' => new ChoiceField(array(
                'id'=>1, 'label'=>'Widget', 'required'=>false,
                'default'=>false,
                'choices'=>array(false=>'Drop Down', true=>'Typeahead'),
                'hint'=>'Typeahead will work better for large lists'
            )),
            '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),
            )),
        );
    }

    function getChoices() {
        if (!$this->_choices) {
            $this->_choices = array();
            foreach ($this->getList()->getItems() as $i)
                $this->_choices[$i->get('id')] = $i->get('value');
        }
        return $this->_choices;
    }

    function export($value) {
        if ($value && is_numeric($value)
                && ($item = DynamicListItem::lookup($value)))
            return $item->toString();
        return $value;
    }
}

class SelectionWidget extends ChoicesWidget {
    function render($mode=false) {
        $config = $this->field->getConfiguration();
        $value = false;
        if ($this->value instanceof DynamicListItem) {
            // Loaded from database
            $value = $this->value->get('id');
            $name = $this->value->get('value');
        } elseif ($this->value) {
            // Loaded from POST
            $value = $this->value;
            $name = $this->getEnteredValue();
        }
        if (!$config['typeahead'] || $mode=='search') {
            $this->value = $value;
            return parent::render($mode);
        }

        $source = array();
        foreach ($this->field->getList()->getItems() as $i)
            $source[] = array(
                'value' => $i->get('value'), 'id' => $i->get('id'),
                'info' => $i->get('value')." -- ".$i->get('extra'),
            );
        ?>
        <span style="display:inline-block">
        <input type="text" size="30" name="<?php echo $this->name; ?>"
            id="<?php echo $this->name; ?>" value="<?php echo $name; ?>"
            placeholder="<?php echo $config['prompt'];
            ?>" autocomplete="off" />
        <input type="hidden" name="<?php echo $this->name;
            ?>_id" id="<?php echo $this->name; ?>_id" value="<?php echo $value; ?>"/>
        <script type="text/javascript">
        $(function() {
            $('input#<?php echo $this->name; ?>').typeahead({
                source: <?php echo JsonDataEncoder::encode($source); ?>,
                property: 'info',
                onselect: function(item) {
                    $('input#<?php echo $this->name; ?>').val(item['value'])
                    $('input#<?php echo $this->name; ?>_id').val(item['id'])
                }
            });
        });
        </script>
        </span>
        <?php
    }

    function getValue() {
        $data = $this->field->getSource();
        // Search for HTML form name first
        if (isset($data[$this->name.'_id']))
            return (int) $data[$this->name.'_id'];
        return parent::getValue();
    }

    function getEnteredValue() {
        // Used to verify typeahead fields
        return parent::getValue();
    }
}
?>