[DX] Remove direct use of new Node() and other direct instantiations of entity classes from the codebase

[argiepiano]

When Backdrop partially incorporated D7 Entity API into core, and switched to using named classes for its core entities (that is, Node and User etc instead of stdClass), this allowed developers to extend those entity class (and their entity controllers) to incorporate additional functionalities and properties. This can be done very simply and efficiently, by (1) implementing a hook_entity_info_alter() to change the entity class and the entity controller, and (2) extending the entity class and/or the entity controller class with the new functionality or properties.

Unfortunately, at the same time, a few places in Backdrop codebase instantiate those core entity classes by making direct calls, as in $node = new Node();. This effectively curtails the new possibilities created by the use of named classes as described above. So, if you are a developer who wants to transform/expand nodes in new ways, you are limited by those few direct instantiations (so, in those places, the resulting entity of calling $node = new Node(); will use the core class, instead of the class you created to extend nodes).

The solution here is to replace those few new Node() and similar calls, with the intermediary API function entity_create('node');. This call will take care of instantiating the entity class as defined in the entity_info_alter hook.

There are very few direct instantiations of core entity classes in the codebase:

• 7 for Node()
• 4 for User()
• 22 for File()
• 2 for Comment()
• 6 for TaxonomyTerm()

Many of those are in tests, which we can simply leave alone, as we want to use the core classes in tests.

[argiepiano]

Further, Drupal discourages instantiating classes directly. Instead their coding standards ask for the use of factory functions - such as entity_create() of entity_get_controller('node')->create().

[kiamlaluno]

Object-oriented code / Instantiation

[kiamlaluno]

(Please disregard this comment. I apologize if it came out inappropriate or offensive toward a specific community.)

[argiepiano]

@kiamlaluno the example you provide actually does not instantiate a Node object directly, so it doesn't break that rule. That code calls a static factory method, which is one of the ways to avoid using direct instantiation.

Direct instantiation is when you use new Something() to instantiate an object.