class.dynamic_forms.php

            $this->_form = new CustomForm($fields, $source, $options);
        }


        return $this->_form;
    }

    function getDynamicFields() {
        return $this->form->fields;
    }

    function getMedia() {
        return $this->getForm()->getMedia();
    }

    function getFields() {
        if (!isset($this->_fields)) {
            $this->_fields = array();
            // Get all dynamic fields associated with the form
            // even when stored elsewhere -- important during validation
            foreach ($this->getDynamicFields() as $f) {
                $f = $f->getImpl($f);
                $this->_fields[$f->get('id')] = $f;
                $f->isnew = true;
            }
            // Include any other answers included in this entry, which may
            // be for fields which have since been deleted
            foreach ($this->getAnswers() as $a) {
                $f = $a->getField();
                $id = $f->get('id');
                if (!isset($this->_fields[$id])) {
                    // This field is not currently on the associated form
                    $a->deleted = true;
                }
                $this->_fields[$id] = $f;
                // This field has an answer, so it isn't new (to this entry)
                $f->isnew = false;
            }
        }
        return $this->_fields;
    }

    function filterFields($filter) {
        $this->getFields();
        foreach ($this->_fields as $i=>$f) {
            if ($filter($f))
                unset($this->_fields[$i]);
        }
    }

    function getSource() {
        return $this->_source ?: (isset($this->id) ? false : $_POST);
    }
    function setSource($source) {
        $this->_source = $source;
        // Ensure the field is connected to this data source
        foreach ($this->getFields() as $F)
            if (!$F->getForm())
                $F->setForm($this);
    }

    function getField($name) {
        foreach ($this->getFields() as $field)
            if (!strcasecmp($field->get('name'), $name))
                return $field;

        return null;
    }

    /**
     * Validate the form and indicate if there no errors.
     *
     * Parameters:
     * $filter - (callback) function to receive each field and return
     *      boolean true if the field's errors are significant
     * $options - options to pass to form and fields.
     *
     */
    function isValid($filter=false, $options=array()) {

        if (!is_array($this->_errors)) {
            $form = $this->getForm(false, $options);
            $form->isValid($filter);
            $this->_errors = $form->errors();
        }

        return !$this->_errors;
    }

    function isValidForClient() {
        $filter = function($f) {
            return $f->isVisibleToUsers();
        };
        return $this->isValid($filter);
    }

    function isValidForStaff() {
        $filter = function($f) {
            return $f->isVisibleToStaff();
        };
        return $this->isValid($filter);
    }

    function getClean() {
        return $this->getForm()->getClean();
    }

    /**
     * Compile a list of data used by the filtering system to match dynamic
     * content in this entry. This returs an array of `field.<id>` =>
     * <value> pairs where the <id> is the field id and the <value> is the
     * toString() value for the entered data.
     *
     * If the field returns an array for its ::getFilterData() method, the
     * data will be added in the array with the keys prefixed with
     * `field.<id>`. This is useful for properties on custom lists, for
     * instance, which can contain properties usefule for matching and
     * filtering.
     */
    function getFilterData() {
        $vars = array();
        foreach ($this->getFields() as $f) {
            $tag = 'field.'.$f->get('id');
            if ($d = $f->getFilterData()) {
                if (is_array($d)) {
                    foreach ($d as $k=>$v) {
                        if (is_string($k))
                            $vars["$tag$k"] = $v;
                        else
                            $vars[$tag] = $v;
                    }
                }
                else {
                    $vars[$tag] = $d;
                }
            }
        }
        return $vars;
    }

    function forTicket($ticket_id, $force=false) {
        static $entries = array();
        if (!isset($entries[$ticket_id]) || $force) {
            $stuff = DynamicFormEntry::objects()
                ->filter(array('object_id'=>$ticket_id, 'object_type'=>'T'));
            // If forced, don't cache the result
            if ($force)
                return $stuff;
            $entries[$ticket_id] = &$stuff;
        }
        return $entries[$ticket_id];
    }
    function setTicketId($ticket_id) {
        $this->object_type = 'T';
        $this->object_id = $ticket_id;
    }

    function setClientId($user_id) {
        $this->object_type = 'U';
        $this->object_id = $user_id;
    }

    function setObjectId($object_id) {
        $this->object_id = $object_id;
    }

    function forObject($object_id, $object_type) {
        return DynamicFormEntry::objects()
            ->filter(array('object_id'=>$object_id, 'object_type'=>$object_type));
    }

    function render($staff=true, $title=false, $options=array()) {
        return $this->getForm()->render($staff, $title, $options);
    }

    function getChanges() {
        $fields = array();
        foreach ($this->getAnswers() as $a) {
            $field = $a->getField();
            if (!$field->hasData() || $field->isPresentationOnly())
                continue;
            $after = $field->to_database($field->getClean());
            $before = $field->to_database($a->getValue());
            if ($before == $after)
                continue;
            $fields[$field->get('id')] = array($before, $after);
        }
        return $fields;
    }

    /**
     * addMissingFields
     *
     * Adds fields that have been added to the linked form (field set) since
     * this entry was originally created. If fields are added to the form,
     * the method will automatically add the fields and null answers to the
     * entry.
     */
    function addMissingFields() {
        foreach ($this->getFields() as $field) {
            if ($field->isnew && $field->isEnabled()
                && !$field->isPresentationOnly()
                && $field->hasData()
                && $field->isStorable()
            ) {
                $a = DynamicFormEntryAnswer::create(
                    array('field_id'=>$field->get('id'), 'entry'=>$this));

                // Add to list of answers
                $this->answers->add($a);

                // Omit fields without data and non-storable fields.
                if (!$field->hasData() || !$field->isStorable())
                    continue;

                $a->save();
            }
        }

        // Sort the form the way it is declared to be sorted
        if ($this->_fields) {
            uasort($this->_fields,
                function($a, $b) {
                    return $a->get('sort') - $b->get('sort');
            });
        }
    }

    /**
     * Save the form entry and all associated answers.
     *
     * Returns:
     * (mixed) FALSE if updated failed, otherwise the number of dirty answers
     * which were save is returned (which may be ZERO).
     */
    function save($refetch=false) {
        if (count($this->dirty))
            $this->set('updated', new SqlFunction('NOW'));

        if (!parent::save($refetch || count($this->dirty)))
            return false;

        $dirty = 0;
        foreach ($this->getAnswers() as $a) {
            $field = $a->getField();

            // Don't save answers for presentation-only fields or fields
            // which are stored elsewhere
            if (!$field->hasData() || !$field->isStorable()
                || $field->isPresentationOnly()
            ) {
                continue;
            }
            // Set the entry here so that $field->getClean() can use the
            // entry-id if necessary
            $a->entry = $this;

            try {
                $field->setForm($this);
                $val = $field->to_database($field->getClean());
            }
            catch (FieldUnchanged $e) {
                // Don't update the answer.
                continue;
            }
            if (is_array($val)) {
                $a->set('value', $val[0]);
                $a->set('value_id', $val[1]);
            }
            else {
                $a->set('value', $val);
            }
            if ($a->dirty)
                $dirty++;
            $a->save();
        }
        return $dirty;
    }

    function delete() {
        if (!parent::delete())
            return false;

        foreach ($this->getAnswers() as $a)
            $a->delete();

        return true;
    }

    static function create($ht=false, $data=null) {
        $inst = parent::create($ht);
        $inst->set('created', new SqlFunction('NOW'));
        if ($data)
            $inst->setSource($data);
        foreach ($inst->getDynamicFields() as $field) {
            if (!($impl = $field->getImpl($field)))
                continue;
            if (!$impl->hasData() || !$impl->isStorable())
                continue;
            $a = DynamicFormEntryAnswer::create(
                array('field'=>$field, 'entry'=>$inst));
            $a->field->setAnswer($a);
            $inst->answers->add($a);
        }
        return $inst;
    }
}

/**
 * Represents a single answer to a single field on a dynamic form. The
 * data / answer to the field is linked back to the form and field which was
 * originally used for the submission.
 */
class DynamicFormEntryAnswer extends VerySimpleModel {

    static $meta = array(
        'table' => FORM_ANSWER_TABLE,
        'ordering' => array('field__sort'),
        'pk' => array('entry_id', 'field_id'),
        'select_related' => array('field'),
        'fields' => array('entry_id', 'field_id', 'value', 'value_id'),
        'joins' => array(
            'field' => array(
                'constraint' => array('field_id' => 'DynamicFormField.id'),
            ),
            'entry' => array(
                'constraint' => array('entry_id' => 'DynamicFormEntry.id'),
            ),
        ),
    );

    var $_field;
    var $deleted = false;
    var $_value;

    function getEntry() {
        return $this->entry;
    }

    function getForm() {
        return $this->getEntry()->getForm();
    }

    function getField() {
        if (!isset($this->_field)) {
            $this->_field = $this->field->getImpl($this->field);
            $this->_field->setAnswer($this);
        }
        return $this->_field;
    }

    function getValue() {
        if (!isset($this->_value) && isset($this->value)) {
            //XXX: We're settting the value here to avoid infinite loop
            $this->_value = false;
            $this->_value = $this->getField()->to_php(
                $this->get('value'), $this->get('value_id'));
        }

        return $this->_value;
    }

    function getLocal($tag) {
        return $this->field->getLocal($tag);
    }

    function getIdValue() {
        return $this->get('value_id');
    }

    function isDeleted() {
        return $this->deleted;
    }

    function toString() {
        return $this->getField()->toString($this->getValue());
    }

    function display() {
        return $this->getField()->display($this->getValue());
    }

    function getSearchable($include_label=false) {
        if ($include_label)
            $label = Format::searchable($this->getField()->getLabel()) . " ";
        return sprintf("%s%s", $label,
            $this->getField()->searchable($this->getValue())
        );
    }

    function getSearchKeys() {
        return implode(',', (array) $this->getField()->getKeys($this->getValue()));
    }

    function asVar() {
        return $this->getField()->asVar(
            $this->get('value'), $this->get('value_id')
        );
    }

    function getVar($tag) {
        if (is_object($var = $this->asVar()) && method_exists($var, 'getVar'))
            return $var->getVar($tag);
    }

    function __toString() {
        $v = $this->toString();
        return is_string($v) ? $v : (string) $this->getValue();
    }

    function delete() {
        if (!parent::delete())
            return false;

        // Allow the field to cleanup anything else in the database
        $this->getField()->db_cleanup();
        return true;
    }
}

class SelectionField extends FormField {
    static $widget = 'ChoicesWidget';

    function getListId() {
        list(,$list_id) = explode('-', $this->get('type'));
        return $list_id ?: $this->get('list_id');
    }

    function getList() {
        if (!$this->_list)
            $this->_list = DynamicList::lookup($this->getListId());

        return $this->_list;
    }

    function getWidget($widgetClass=false) {
        $config = $this->getConfiguration();
        if ($config['widget'] == 'typeahead' && $config['multiselect'] == false)
            $widgetClass = 'TypeaheadSelectionWidget';
        elseif ($config['widget'] == 'textbox')
            $widgetClass = 'TextboxSelectionWidget';

        return parent::getWidget($widgetClass);
    }

    function parse($value) {

        if (!($list=$this->getList()))
            return null;

        $config = $this->getConfiguration();
        $choices = $this->getChoices();
        $selection = array();

        if ($value && !is_array($value))
            $value = array($value);

        if ($value && is_array($value)) {
            foreach ($value as $k=>$v) {
                if ($k && ($i=$list->getItem((int) $k)))
                    $selection[$i->getId()] = $i->getValue();
                elseif (isset($choices[$k]))
                    $selection[$k] = $choices[$k];
                elseif (isset($choices[$v]))
                    $selection[$v] = $choices[$v];
                elseif (($i=$list->getItem($v, true)))
                    $selection[$i->getId()] = $i->getValue();
            }
        } elseif($value) {
            //Assume invalid textbox input to be validated
            $selection[] = $value;
        }

        // Don't return an empty array
        return $selection ?: null;
    }

    function to_database($value) {
        if (is_array($value)) {
            reset($value);
        }
        if ($value && is_array($value))
            $value = JsonDataEncoder::encode($value);

        return $value;
    }

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

        if (!is_array($value)) {
            $values = array();
            $choices = $this->getChoices();
            foreach (explode(',', $value) as $V) {
                if (isset($choices[$V]))
                    $values[$V] = $choices[$V];
            }
            if ($id && isset($choices[$id]))
                $values[$id] = $choices[$id];

            if ($values)
                return $values;
            // else return $value unchanged
        }
        // Don't set the ID here as multiselect prevents using exactly one
        // ID value. Instead, stick with the JSON value only.
        return $value;
    }

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

    // PHP 5.4 Move this to a trait
    function whatChanged($before, $after) {
        $before = (array) $before;
        $after = (array) $after;
        $added = array_diff($after, $before);
        $deleted = array_diff($before, $after);
        $added = array_map(array($this, 'display'), $added);
        $deleted = array_map(array($this, 'display'), $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 {
            $desc = sprintf(
                __('changed to <strong>%1$s</strong>'),
                $this->display($after));
        }
        return $desc;
    }

    function asVar($value, $id=false) {
        $values = $this->to_php($value, $id);
        if (is_array($values)) {
            return new PlaceholderList($this->getList()->getAllItems()
                ->filter(array('id__in' => array_keys($values)))
            );
        }
    }

    function hasSubFields() {
        return $this->getList()->getForm();
    }
    function getSubFields() {
        $fields = new ListObject(array(
            new TextboxField(array(
                // XXX: i18n: Change to a better word when the UI changes
                'label' => '['.__('Abbrev').']',
                'id' => 'abb',
            ))
        ));
        $form = $this->getList()->getForm();
        if ($form && ($F = $form->getFields()))
            $fields->extend($F);
        return $fields;
    }

    function toString($items) {
        return is_array($items)
            ? implode(', ', $items) : (string) $items;
    }

    function validateEntry($entry) {
        parent::validateEntry($entry);
        if (!$this->errors()) {
            $config = $this->getConfiguration();
            if ($config['widget'] == 'textbox') {
                if ($entry && (
                        !($k=key($entry))
                     || !($i=$this->getList()->getItem((int) $k))
                 )) {
                    $config = $this->getConfiguration();
                    $this->_errors[] = $this->getLocal('validator-error', $config['validator-error'])
                        ?: __('Unknown or invalid input');
                }
            } elseif ($config['typeahead']
                    && ($entered = $this->getWidget()->getEnteredValue())
                    && !in_array($entered, $entry))
                $this->_errors[] = __('Select a value from the list');
        }
    }

    function getConfigurationOptions() {
        return array(
            'multiselect' => new BooleanField(array(
                'id'=>2,
                'label'=>__(/* Type of widget allowing multiple selections */ 'Multiselect'),
                'required'=>false, 'default'=>false,
                'configuration'=>array(
                    'desc'=>__('Allow multiple selections')),
            )),
            'widget' => new ChoiceField(array(
                'id'=>1,
                'label'=>__('Widget'),
                'required'=>false, 'default' => 'dropdown',
                'choices'=>array(
                    'dropdown' => __('Drop Down'),
                    'typeahead' => __('Typeahead'),
                    'textbox' => __('Text Input'),
                ),
                'configuration'=>array(
                    'multiselect' => false,
                ),
                'visibility' => new VisibilityConstraint(
                    new Q(array('multiselect__eq'=>false)),
                    VisibilityConstraint::HIDDEN
                ),
                'hint'=>__('Typeahead will work better for large lists')
            )),
            'validator-error' => new TextboxField(array(
                'id'=>5, 'label'=>__('Validation Error'), 'default'=>'',
                'configuration'=>array('size'=>40, 'length'=>80,
                    'translatable'=>$this->getTranslateTag('validator-error')
                ),
                'visibility' => new VisibilityConstraint(
                    new Q(array('widget__eq'=>'textbox')),
                    VisibilityConstraint::HIDDEN
                ),
                'hint'=>__('Message shown to user if the item entered is not in the list')
            )),
            'prompt' => new TextboxField(array(
                'id'=>3,
                'label'=>__('Prompt'), 'required'=>false, 'default'=>'',
                'hint'=>__('Leading text shown before a value is selected'),
                'configuration'=>array('size'=>40, 'length'=>40,
                    'translatable'=>$this->getTranslateTag('prompt'),
                ),
            )),
            'default' => new SelectionField(array(
                'id'=>4, 'label'=>__('Default'), 'required'=>false, 'default'=>'',
                'list_id'=>$this->getListId(),
                'configuration' => array('prompt'=>__('Select a Default')),
            )),
        );
    }

    function getConfiguration() {

        $config = parent::getConfiguration();
        if ($config['widget'])
            $config['typeahead'] = $config['widget'] == 'typeahead';

        // Drop down list does not support multiple selections
        if ($config['typeahead'])
            $config['multiselect'] = false;

        return $config;
    }

    function getChoices($verbose=false) {
        if (!$this->_choices || $verbose) {
            $choices = array();
            foreach ($this->getList()->getItems() as $i)
                $choices[$i->getId()] = $i->getValue();

            // Retired old selections
            $values = ($a=$this->getAnswer()) ? $a->getValue() : array();
            if ($values && is_array($values)) {
                foreach ($values as $k => $v) {
                    if (!isset($choices[$k])) {
                        if ($verbose) $v .= ' '.__('(retired)');
                        $choices[$k] = $v;
                    }
                }
            }

            if ($verbose) // Don't cache
                return $choices;

            $this->_choices = $choices;
        }

        return $this->_choices;
    }

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

        return $selection;
    }

    function lookupChoice($value) {

        // See if it's in the choices.
        $choices = $this->getChoices();
        if ($choices && ($i=array_search($value, $choices)))
            return array($i=>$choices[$i]);

        // Query the store by value or extra (abbrv.)
        if (!($list=$this->getList()))
            return null;

        if ($i = $list->getItem($value))
            return array($i->getId() => $i->getValue());

        if ($i = $list->getItem($value, true))
            return array($i->getId() => $i->getValue());

        return null;
    }


    function getFilterData() {
        // Start with the filter data for the list item as the [0] index
        $data = array(parent::getFilterData());
        if (($v = $this->getClean())) {
            // Add in the properties for all selected list items in sub
            // labeled by their field id
            foreach ($v as $id=>$L) {
                if (!($li = DynamicListItem::lookup($id)))
                    continue;
                foreach ($li->getFilterData() as $prop=>$value) {
                    if (!isset($data[$prop]))
                        $data[$prop] = $value;
                    else
                        $data[$prop] .= " $value";
                }
            }
        }
        return $data;
    }

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

    function getSearchMethodWidgets() {
        return array(
            'set' => null,
            'notset' => 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 ?: $this->get('name');
        switch ($method) {
        case '!includes':
            return Q::not(array("{$name}__intersect" => array_keys($value)));
        case 'includes':
            return new Q(array("{$name}__intersect" => array_keys($value)));
        default:
            return parent::getSearchQ($method, $value, $name);
        }
    }
}

class TypeaheadSelectionWidget extends ChoicesWidget {
    function render($options=array()) {

        if ($options['mode'] == 'search')
            return parent::render($options);

        $name = $this->getEnteredValue();
        $config = $this->field->getConfiguration();
        if (is_array($this->value)) {
            $name = $name ?: current($this->value);
            $value = key($this->value);
        }
        else {
            // Pull configured default (if configured)
            $def_key = $this->field->get('default');
            if (!$def_key && $config['default'])
                $def_key = $config['default'];
            if (is_array($def_key))
                $name = current($def_key);
        }

        $source = array();
        foreach ($this->field->getList()->getItems() as $i)
            $source[] = array(
                'value' => $i->getValue(), 'id' => $i->getId(),
                'info' => sprintf('%s%s',
                    $i->getValue(),
                    (($extra= $i->getAbbrev()) ? " — $extra" : '')),
            );
        ?>
        <span style="display:inline-block">
        <input type="text" size="30" name="<?php echo $this->name; ?>_name"
            id="<?php echo $this->name; ?>" value="<?php echo Format::htmlchars($name); ?>"
            placeholder="<?php echo $config['prompt'];
            ?>" autocomplete="off" />
        <input type="hidden" name="<?php echo $this->name;
            ?>_id" id="<?php echo $this->name;
            ?>_id" value="<?php echo Format::htmlchars($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; ?>_name').val(item['value'])
                    $('input#<?php echo $this->name; ?>_id')
                      .attr('name', '<?php echo $this->name; ?>[' + item['id'] + ']')
                      .val(item['value']);
                    return false;
                }
            });
        });
        </script>
        </span>
        <?php
    }

    function parsedValue() {
        return array($this->getValue() => $this->getEnteredValue());
    }

    function getValue() {
        $data = $this->field->getSource();
        $name = $this->field->get('name');
        if (isset($data["{$this->name}_id"]) && is_numeric($data["{$this->name}_id"])) {
            return array($data["{$this->name}_id"] => $data["{$this->name}_name"]);
        }
        elseif (isset($data[$name])) {
            return $data[$name];
        }
        // Attempt to lookup typed value (usually from a default)
        elseif ($val = $this->getEnteredValue()) {
            return $this->field->lookupChoice($val);
        }

        return parent::getValue();
    }

    function getEnteredValue() {
        // Used to verify typeahead fields
        $data = $this->field->getSource();
        if (isset($data[$this->name.'_name'])) {
            // Drop the extra part, if any
            $v = $data[$this->name.'_name'];
            $pos = strrpos($v, ' — ');
            if ($pos !== false)
                $v = substr($v, 0, $pos);

            return trim($v);
        }
        return parent::getValue();
    }
}
?>