Creating a custom field/widget

Question

I'm trying to create a field that is a combination of two fields. The first field needs to a reference to another entity (just like in the entityreference module). The second field is just a text field (using the textarea widget).

Here's the code I have so far.

sample.install:

function sample_field_schema($field) {
    $schema = array(
        'columns' => array(
            'place_id' => array(
                'type' => 'int',
                'unsigned' => true,
                'not null' => true
            ),
            'quote' => array(
                'type' => 'text',
                'size' => 'big',
                'not null' => false
            )
        ),
        'indexes' => array(
            'place_id' => array('place_id')
        ),
        'foreign keys' => array()
    );

    $entity_type = 'place';
    $bundles = field_info_bundles('node');
    if (!empty($bundles['place'])) {
        $schema['foreign keys']['place'] = array(
            'table' => 'place',
            'columns' => array('place_id' => 'nid')
        );
    }

    return $schema;
}

sample.module:

function sample_field_info() {
    return array(
        'sample_field' => array(
            'label' => t('Label'),
            'description' => t('description.'),
            'default_widget' => 'sample_field_widget',
            'default_formatter' => 'sample_field_formatter',
            'settings' => array(),
            'instance_settings' => array(),
        )
    );
}

function sample_field_formatter_info() {
    return array(
        'sample_field_formatter' => array(
            'label' => t('sample formatter'),
            'field types' => array('sample_field')
        )
    );
}

function sample_field_formatter_view($entity_type, $entity, $field, $instance, $lang, $items, $display) {
    $element = array();

    switch ($display['type']) {
        case 'sample_field_formatter':
            // I'm not really familiar with these bits ... this is just to output *something*
            $element[]['#markup'] = var_export($items, true);
            break;
    }

    return $element;
}

function sample_field_widget_form(&$form, &$form_state, $field, $instance, $lang, $items, $delta, $element) {
    switch ($instance['widget']['type']) {
        case 'sample_field_widget':
            $element['place_id'] = array(
                '#type' => 'textfield',
                '#maxlength' => 1024,
                '#title' => t('Place'),
                '#default_value' => isset($items[$delta]['place_id']) ? $items[$delta]['place_id'] : null,
                '#required' => $element['#required'],
                '#weight' => (int)$element['#weight'],
                '#delta' => $delta,
                '#size' => 'big',
                '#autocomplete_path' => 'api/find/places'
            );

            $element['quote'] = array(
                '#type' => 'textarea',
                '#title' => t('Quote'),
                            '#default_value' => isset($items[$delta]['quote']) ? $items[$delta]['quote'] : null,
            );
            break;
    }

    return $element;
}

function sample_widget_error($element, $error, $form, &$form_state) {
    switch ($error['error']) {
        case 'sample_field_invalid':
            form_error($element, $error['message']);
            break;
    }
}

function sample_field_is_empty($item, $field) {
    if (empty($item['sample_field'])) {
        return true;
    }
}

function sample_field_widget_info() {
    return array(
        'sample_field_widget' => array(
            'label' => t('Sample Field Widget'),
            'field types' => array('sample_field'),
            'settings' => array(),
            'behaviors' => array(
                'default value' => FIELD_BEHAVIOR_NONE
            )
        )
    );
}

So this all gives me a new field type and a new widget for that field. When I edit/create new content that has this field type, the widget shows up properly with both fields but when I submit to insert/update the content, the fields are not saved. How can I get the form to save the field data for this custom field and how can I get that data to be loaded again when the content is edited?

Answer 1

You're missing hook_field_validate() which apparently is required for this to work. See this blog post (which you may have already -- I'm just comparing what he did to your code) ... http://www.agileapproach.com/blog-entry/compound-fields-drupal-7

Answer 2

It was my hook_field_is_empty() implementation. It was returning true in cases where it shouldn't have. Just make sure hook_field_is_empty() is properly checking for empty values.