Add Flask extension module

src/dependency_injector/ext/flask.py

@@ -2,15 +2,82 @@
 
 from flask import Flask
 
+from dependency_injector import providers, errors
 
-def create_app(name, routes):
-    app = Flask(name)
+
+def create_app(name, routes, **kwargs):
+    """Create Flask app and add routes."""
+    app = Flask(name, **kwargs)
     for route in routes:
-        app.add_url_rule(*route.args, **route.kwargs)
+        app.add_url_rule(*route.args, **route.options)
     return app
 
 
+def as_view(provider, name=None):
+    """Transform class-based view provider to view function."""
+    if isinstance(provider, providers.Factory):
+        def view(*args, **kwargs):
+            self = provider()
+            return self.dispatch_request(*args, **kwargs)
+
+        assert name, 'Argument "endpoint" is required for class-based views'
+        view.__name__ = name
+    elif isinstance(provider, providers.Callable):
+        def view(*args, **kwargs):
+            return provider(*args, **kwargs)
+
+        view.__name__ = provider.provides.__name__
+    else:
+        raise errors.Error('Undefined provider type')
+
+    view.__doc__ = provider.provides.__doc__
+    view.__module__ = provider.provides.__module__
+
+    if isinstance(provider.provides, type):
+        view.view_class = provider.provides
+
+    if hasattr(provider.provides, 'decorators'):
+        for decorator in provider.provides.decorators:
+            view = decorator(view)
+
+    if hasattr(provider.provides, 'methods'):
+        view.methods = provider.provides.methods
+
+    if hasattr(provider.provides, 'provide_automatic_options'):
+        view.provide_automatic_options = provider.provides.provide_automatic_options
+
+    return view
+
+
 class Route:
-    def __init__(self, *args, **kwargs):
-        self.args = args
-        self.kwargs = kwargs
+    """Route is a glue for Dependency Injector providers and Flask views."""
+
+    def __init__(
+            self,
+            rule,
+            endpoint=None,
+            view_provider=None,
+            provide_automatic_options=None,
+            **options,
+    ):
+        """Initialize route."""
+        self.view_provider = view_provider
+        self.args = (rule, endpoint, as_view(view_provider, endpoint), provide_automatic_options)
+        self.options = options
+
+    def __deepcopy__(self, memo):
+        """Create and return full copy of provider."""
+        copied = memo.get(id(self))
+        if copied is not None:
+            return copied
+
+        rule, endpoint, _, provide_automatic_options = self.args
+        view_provider = providers.deepcopy(self.view_provider, memo)
+
+        return self.__class__(
+            rule,
+            endpoint,
+            view_provider,
+            provide_automatic_options,
+            **self.options,
+        )