Drupal 7 Module Development

Creating New Fields
}
}
}
$element['dimfield_combined_wrapper']['#theme'] =
'dimfield_combined_wrapper';
$element['dimfield_combined_wrapper']['height_width_depth'] =
array('#type' => 'textfield',
'#default_value' => $default,
'#size' => $instance['widget']['settings']['size'],
) + $base;
$element['dimfield_combined_wrapper']['units'] = array(
'#type' => 'select',
'#title' => t('Units'),
'#default_value' => isset($items[$delta]['units']) ?
$items[$delta]['units'] : NULL,
'#options' => dimfield_units(),
);
}
return $element;
In the first block of code, we assemble our default value for the form element out of
the values available in the field. Since our widget is only handling a single instance,
we have to check for just this one delta to see if we have a value defined. If so, we
concatenate the height, width, and potential depth together with an × between them.
Then we set up our two form elements. One is our combined height, width, and
depth text field and the other is the units, as we've seen before. The most important
part, however, is that very first line:
$element['#element_validate'] = array('_dimfield_combined_validate');
Just as we specified an existing validation callback for a text field a moment ago, this
time we will specify a custom validation callback. However, we won't be using it just
for validation. Rather, we will be using it to modify the submitted form values. Let's
have a look at that function given here:
function _dimfield_combined_validate($element, &$form_state) {
// This function is also called when submitting the field
// configuration form. If so, skip validation as it
// won't work anyway.
if ($form_state['complete form']['#form_id'] ==
[ 196 ]