Enforcedefaults aiohttp (#1163)

* cache ConnexionRequest.json

* add openapi3 enforcedefaults_aiohttp example

Co-authored-by: Robbe Sneyders <robbe.sneyders@ml6.eu>

connexion/lifecycle.py

@@ -30,7 +30,9 @@ class ConnexionRequest:
 
     @property
     def json(self):
-        return self.json_getter()
+        if not hasattr(self, '_json'):
+            self._json = self.json_getter()
+        return self._json
 
 
 class ConnexionResponse:

examples/openapi3/enforcedefaults_aiohttp/README.rst

@@ -0,0 +1,16 @@
+========================
+Custom Validator Example
+========================
+
+In this example we fill-in non-provided properties with their defaults.
+Validator code is based on example from `python-jsonschema docs`_.
+
+Running:
+
+.. code-block:: bash
+
+    $ ./enforcedefaults.py
+
+Now open your browser and go to http://localhost:8080/v1/ui/ to see the Swagger
+UI. If you send a ``POST`` request with empty body ``{}``, you should receive
+echo with defaults filled-in.

examples/openapi3/enforcedefaults_aiohttp/enforcedefaults-api.yaml

@@ -0,0 +1,39 @@
+openapi: '3.0.0'
+info:
+  version: '1'
+  title: Custom Validator Example
+servers:
+  - url: http://localhost:8080/{basePath}
+    variables:
+      basePath:
+        default: api
+paths:
+  /echo:
+    post:
+      description: Echo passed data
+      operationId: enforcedefaults.echo
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/Data'
+      responses:
+        '200':
+          description: Data with defaults filled in by validator
+        default:
+          description: Unexpected error
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+components:
+  schemas:
+    Data:
+      type: object
+      properties:
+        foo:
+          type: string
+          default: foo
+    Error:
+      type: string

examples/openapi3/enforcedefaults_aiohttp/enforcedefaults.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+
+import connexion
+import jsonschema
+import six
+from connexion.decorators.validation import RequestBodyValidator
+from connexion.json_schema import Draft4RequestValidator
+
+
+async def echo(body):
+    return body
+
+
+# via https://python-jsonschema.readthedocs.io/
+def extend_with_set_default(validator_class):
+    validate_properties = validator_class.VALIDATORS['properties']
+
+    def set_defaults(validator, properties, instance, schema):
+        for property, subschema in six.iteritems(properties):
+            if 'default' in subschema:
+                instance.setdefault(property, subschema['default'])
+
+        for error in validate_properties(
+                validator, properties, instance, schema):
+            yield error
+
+    return jsonschema.validators.extend(
+        validator_class, {'properties': set_defaults})
+
+DefaultsEnforcingDraft4Validator = extend_with_set_default(Draft4RequestValidator)
+
+
+class DefaultsEnforcingRequestBodyValidator(RequestBodyValidator):
+    def __init__(self, *args, **kwargs):
+        super(DefaultsEnforcingRequestBodyValidator, self).__init__(
+            *args, validator=DefaultsEnforcingDraft4Validator, **kwargs)
+
+
+validator_map = {
+    'body': DefaultsEnforcingRequestBodyValidator
+}
+
+
+if __name__ == '__main__':
+    app = connexion.AioHttpApp(
+        __name__,
+        port=8080,
+        specification_dir='.',
+        options={'swagger_ui': True}
+    )
+    app.add_api(
+        'enforcedefaults-api.yaml',
+        arguments={'title': 'Hello World Example'},
+        validator_map=validator_map,
+    )
+    app.run()