Hello Everyone, we would like to propose an adaptation to the RestoreBackupFileContent.py to keep it in line with domain-driven design principles. This is our inital thought process, and would love any feedback from the community before doing a pull request.
The RestoreBackupFileContent class is a simple data container with no behavior. It violates the principle of rich domain models in Domain-Driven Design (DDD), where entities should encapsulate both data and behavior. Currently, all logic related to restoring backups is scattered across various functions, such as _extract_backup and _clear_configuration_directory, rather than being encapsulated within the domain model itself.
Code Snippet: @dataclass
class RestoreBackupFileContent:
"""Definition for restore backup file content."""
backup_file_path: Path
password: str | None
remove_after_restore: bool
restore_database: bool
restore_homeassistant: bool
Problem: This class only holds data but does not encapsulate any behavior related to restoring backups or clearing directories. This leads to:
Low Cohesion: The logic for backup restoration is scattered across multiple functions, such as _extract_backup and _clear_configuration_directory, making the code harder to maintain and test.
Violation of DDD Principles: The class does not group state and behavior, resulting in an Anemic Domain Model.
Increased Risk of Duplication: Since functionality isn’t grouped with the data it affects, similar logic may be repeated or inconsistently applied elsewhere.
Proposal: To refactor this class with DDD principles in mind, the best course of action would be to quit treating this class as a dataclass and instead add behaviors/methods as well. This would treat our class as a rich-domain and would not violate the concept of bundling states and behavior into domains. Some ideal functionality would be method calls for actually restoring the code base from prior backups, or a default state method that would reset your client to base configuration.
To address the issue, the RestoreBackupFileContent class could be refactored to also have behavior that can backup restoration. This transforms it into a rich domain model which aligns better with DDD principles.
Refactored Code Snippet:
@dataclass
class RestoreBackupFileContent:
"""Definition for restore backup file content with behavior."""
backup_file_path: Path
password: str | None
remove_after_restore: bool
restore_database: bool
restore_homeassistant: bool
self.backup_file_path = backup_file_path
self.password = password
self.remove_after_restore = remove_after_restore
self.restore_database = restore_database
self.restore_homeassistant = restore_homeassistant
def extract_backup(self, config_dir: Path) -> None:
"""Extract the backup file to the config directory."""
# Logic for extracting the backup
def clear_configuration_directory(self, config_dir: Path, keep: Iterable[str]) -> None:
"""Clear the configuration directory except for specified files."""
# Logic for clearing the directory
def restore_database(self, config_dir: Path) -> None:
"""Restore only the database files."""
# actual logic to restore database
Benefits of the Refactor:
Rich Domain Model: The class now encapsulates both state and behavior, which is more in line with the DDD principles.
Improved Cohesion: All logic related to backup restoration is centralized in the class. Testability: The class can be tested independently, as it encapsulates all related behavior.
Maintainability: Changes to backup restoration logic will make it easier to implement and less error-prone.