Target can have multiple form and summary callbacks

With form and summary callbacks for a target, you can supply additional configuration options for your target. The form callbacks are used to provide a form to set the target configuration and the summary callbacks are used to display this configuration.

Two aspects have been changed regarding defining these callbacks:

• The definition names were changed. Use form_callbacks and summary_callbacks instead of form_callback and summary_callback (note that an additional "s" is added to the definition names).
• Instead of one, multiple form and summary callbacks can now be defined. These should now be defined in an array instead of a string.

The old way of defining form and summary callbacks is still supported, but discouraged.

Before:

/**
 * Implements hook_feeds_processor_targets().
 */
function my_module_feeds_processor_targets($entity_type, $bundle) {
  $targets['my_target'] = array(
    'name' => t('My target'),
    'description' => t('A target with additional configuration.'),
    'callback' => 'my_module_set_target',
    'form_callback' => 'my_module_form_callback',
    'summary_callback' => 'my_module_summary_callback',
  );
}

After:

/**
 * Implements hook_feeds_processor_targets().
 */
function my_module_feeds_processor_targets($entity_type, $bundle) {
  $targets['my_target'] = array(
    'name' => t('My target'),
    'description' => t('A target with additional configuration.'),
    'callback' => 'my_module_set_target',
    'form_callbacks' => array('my_module_form_callback'),
    'summary_callbacks' => array('my_module_summary_callback'),
  );
}