In Rails applications, callback methods are internal implementation details that should not be part of a model’s public interface. When callback
methods are declared as public, they can be called directly from outside the model, which violates the principle of encapsulation and can lead to
several problems.
Callback methods are designed to be invoked automatically by the Rails framework at specific points in an object’s lifecycle. They often contain
logic that assumes certain preconditions or state changes that only occur during the normal Rails callback chain. When these methods are called
directly, they may not work as expected or could cause data inconsistency.
Additionally, public callback methods expose internal implementation details that other parts of the application might inadvertently depend on.
This creates tight coupling and makes the code harder to refactor or maintain over time.
Following the Rails convention of making callback methods private also improves code readability by clearly distinguishing between the model’s
public API and its internal implementation details.
What is the potential impact?
When callback methods are public, they can be called directly from outside the model, potentially bypassing important validation or state
management logic. This can lead to data inconsistency, unexpected behavior, or security vulnerabilities if the callback methods contain sensitive
operations that should only be triggered through the normal Rails lifecycle.
