From 3903f853683b3f35425e28ee8dce830f4122c6f2 Mon Sep 17 00:00:00 2001
From: Sven Heidemann <sven.heidemann@sh-edraft.de>
Date: Sat, 2 Oct 2021 10:57:54 +0200
Subject: [PATCH] Added logic to handle extensions before running the app

---
 .../application/application_builder.py        | 20 +++++++++++++++++--
 .../application/application_extension_abc.py  | 13 ++++++++++++
 .../custom/general/src/general/application.py |  3 ++-
 src/tests/custom/general/src/general/main.py  |  2 ++
 .../general/src/general/test_extension.py     | 13 ++++++++++++
 5 files changed, 48 insertions(+), 3 deletions(-)
 create mode 100644 src/cpl_core/application/application_extension_abc.py
 create mode 100644 src/tests/custom/general/src/general/test_extension.py

diff --git a/src/cpl_core/application/application_builder.py b/src/cpl_core/application/application_builder.py
index ee3f52a6..27ccb762 100644
--- a/src/cpl_core/application/application_builder.py
+++ b/src/cpl_core/application/application_builder.py
@@ -1,9 +1,12 @@
-from typing import Type, Optional
+import types
+from typing import Type, Optional, Callable
 
 from cpl_core.application.application_abc import ApplicationABC
 from cpl_core.application.application_builder_abc import ApplicationBuilderABC
+from cpl_core.application.application_extension_abc import ApplicationExtensionABC
 from cpl_core.application.startup_abc import StartupABC
 from cpl_core.configuration.configuration import Configuration
+from cpl_core.console import Console
 from cpl_core.dependency_injection.service_collection import ServiceCollection
 
 
@@ -25,12 +28,25 @@ class ApplicationBuilder(ApplicationBuilderABC):
         self._environment = self._configuration.environment
         self._services = ServiceCollection(self._configuration)
 
+        self._extensions: list[Callable] = []
+
     def use_startup(self, startup: Type[StartupABC]):
         self._startup = startup()
 
+    def use_extension(self, extension: Type[ApplicationExtensionABC]):
+        if extension not in self._extensions:
+            self._extensions.append(extension)
+
     def build(self) -> ApplicationABC:
         if self._startup is not None:
             self._startup.configure_configuration(self._configuration, self._environment)
             self._startup.configure_services(self._services, self._environment)
 
-        return self._app(self._configuration, self._services.build_service_provider())
+        config = self._configuration
+        services = self._services.build_service_provider()
+
+        for ex in self._extensions:
+            extension = ex()
+            extension.run(config, services)
+
+        return self._app(config, services)
diff --git a/src/cpl_core/application/application_extension_abc.py b/src/cpl_core/application/application_extension_abc.py
new file mode 100644
index 00000000..0a6dfc20
--- /dev/null
+++ b/src/cpl_core/application/application_extension_abc.py
@@ -0,0 +1,13 @@
+from abc import ABC, abstractmethod
+
+from cpl_core.configuration import ConfigurationABC
+from cpl_core.dependency_injection import ServiceProviderABC
+
+
+class ApplicationExtensionABC(ABC):
+
+    @abstractmethod
+    def __init__(self): pass
+
+    @abstractmethod
+    def run(self, config: ConfigurationABC, services: ServiceProviderABC): pass
diff --git a/src/tests/custom/general/src/general/application.py b/src/tests/custom/general/src/general/application.py
index a42536af..9e2d4ef0 100644
--- a/src/tests/custom/general/src/general/application.py
+++ b/src/tests/custom/general/src/general/application.py
@@ -37,7 +37,8 @@ class Application(ApplicationABC):
         self._mailer = self._services.get_service(EMailClientABC)
 
     def main(self):
-        self._logger.header(f'{self._configuration.environment.application_name}:')
+        if self._configuration.environment.application_name != '':
+            self._logger.header(f'{self._configuration.environment.application_name}:')
         self._logger.debug(__name__, f'Host: {self._configuration.environment.host_name}')
         self._logger.debug(__name__, f'Environment: {self._configuration.environment.environment_name}')
         self._logger.debug(__name__, f'Customer: {self._configuration.environment.customer}')
diff --git a/src/tests/custom/general/src/general/main.py b/src/tests/custom/general/src/general/main.py
index f6515f12..339c0723 100644
--- a/src/tests/custom/general/src/general/main.py
+++ b/src/tests/custom/general/src/general/main.py
@@ -1,11 +1,13 @@
 from cpl_core.application.application_builder import ApplicationBuilder
 from application import Application
+from general.test_extension import TestExtension
 from startup import Startup
 
 
 def main():
     app_builder = ApplicationBuilder(Application)
     app_builder.use_startup(Startup)
+    app_builder.use_extension(TestExtension)
     app_builder.build().run()
 
 
diff --git a/src/tests/custom/general/src/general/test_extension.py b/src/tests/custom/general/src/general/test_extension.py
new file mode 100644
index 00000000..b314c665
--- /dev/null
+++ b/src/tests/custom/general/src/general/test_extension.py
@@ -0,0 +1,13 @@
+from cpl_core.application.application_extension_abc import ApplicationExtensionABC
+from cpl_core.configuration import ConfigurationABC
+from cpl_core.console import Console
+from cpl_core.dependency_injection import ServiceProviderABC
+
+
+class TestExtension(ApplicationExtensionABC):
+
+    def __init__(self):
+        ApplicationExtensionABC.__init__(self)
+
+    def run(self, config: ConfigurationABC, services: ServiceProviderABC):
+        Console.write_line('Hello World from App Extension')