Facade

hivecore.patterns.Facade(facade_name: str)

Decorator to create a facade wrapper class that interacts with registered subsystems.

Parameters:

facade_name (str) – The name of the facade.

Returns:

The decorated class acting as a facade.

Return type:

class

Subsystem

hivecore.patterns.Subsystem(facade_name: str, **operation_to_method: str)

Decorator to register a class as a subsystem and associate it with a facade.

Parameters:

• facade_name (str) – The name of the facade to associate the subsystem with.

• operation_to_method (Dict[str, str]) – Keyword arguments representing the mapping of operations to methods in the subsystem.

Returns:

The decorated class.

Return type:

class

Example

To implement the facade pattern, the library provides a system to register new clases as subsystems and a system to facade those subsystems. The Subsystem decorator lets the user define a new subsystem and include it into a group and even map functions between the Facade and the Subsystem using kwargs. On the other hand the Facade decorator works as a facade for all subsystems in a given group. The user can then use the operation method to call methods as needed.

Registering Subsystems

We register the following subsystems with the “StreamingFacade” group:

from hivecore.patterns import Subsystem

@Subsystem("StreamingFacade")
class AuthenticationSystem:
    def login(self):
        return "Logging in...\n"

    def logout(self):
        return "Logging out...\n"

@Subsystem("StreamingFacade", login="signin", logout="signout")
class BillingSystem:
    def signin(self):
        return "Signing in to BillingSystem...\n"

    def signout(self):
        return "Signing out from BillingSystem...\n"

    def pay(self):
        return "Paying...\n"

@Subsystem("StreamingFacade")
class StreamingSystem:
    def fetch_movie(self):
        return "Fetching movie...\n"

    def play_movie(self):
        return "Playing movie...\n"

Creating Facade

We create a facade class using the “StreamingFacade” group using the Facade decorator:

from hivecore.patterns import Subsystem, Facade

@Facade("StreamingFacade")
class StreamingFacade:
    pass

Performing Operations

We create an instance of the facade class and perform various operations:

# Create facade object
streaming = StreamingFacade()

# Perform operations
login_result = streaming.operation("login")
pay_result = streaming.operation("pay")
fetch_result = streaming.operation("fetch_movie")
play_result = streaming.operation("play_movie")
logout_result = streaming.operation("logout")

print(login_result)
print(pay_result)
print(fetch_result)
print(play_result)
print(logout_result)

Output

The output of the above example would be:

Logging in...
Paying...
Fetching movie...
Playing movie...
Logging out...