Handling when a host entity is unavailable

Following on from legitimate issues reported in: #1599396: Fatal Error: Call to a member function internalIdentifier() on a non-object and #1621686: Call to a member function internalIdentifier() on a non-object in registration/includes/registration.forms.inc line 90

Resolve when properties of Registration entities when they are of an unacceptable value.

Eg: author of registration no longer exist will cause Registration->author->uid to result in not an object/not set error.

Affected properties:

• Registration->author
• Registration->entity
• Registration->state
• Registration->user

Code should not use isset($registration->author). When $registration->author is unavailable, it will be FALSE. isset(FALSE) results in true. Instead, simply checking for boolean true is enough.

Please see patch.

Issues not covered in patch

Autoloading entities

Consider modifying Registration::__construct so it does not autoload entities. Not all entities should autoload its related entities, why should Registration do the same.

Remove Registration->author/entity/state/user properties.

Make user/entity/state/user methods public. Each of these methods have their related entities statically cached by Drupal. So there is no performance loss.

Entity metadata wrappers

Implement hook_entity_property_info so existing registration entity properties still operate normally.

See also:

• Entity metadata wrappers
• entity_metadata_wrapper