Adds Configuration Options (#15)

Although nothing is currently stored in the class instance, this change just allows the app registration to be done after instantiation.

docs/source/index.md

@@ -165,7 +165,7 @@ class PostRequest(JsonRequest):
 
 ### Error Messages Format
 
-In case validation fails to pass, the following is the format of the generated response:
+In case validation fails to pass, the following is the default format of the generated response:
 ```js
 {
     success: False,
@@ -181,7 +181,19 @@ In case validation fails to pass, the following is the format of the generated r
     }
 }
 ```
-All validation error messages will have a HTTP error status code 400.
+
+This format can be configured using the following flask configurations:
+- `SIEVE_RESPONSE_MESSAGE` - Set this to modify your default error message e.g "Invalid Input".
+- `SIEVE_INCLUDE_SUCCESS_KEY` - Set this to False to remove the success key from the response.
+- `SIEVE_RESPONSE_WRAPPER` - Set this to wrap your response e.g. `data`.
+
+
+### Response Status Code
+
+By default, all validation error messages will have a HTTP error status code 400. This can be configured by setting the flask config `SIEVE_INVALID_STATUS_CODE`.
+```python
+app.config['SIEVE_INVALID_STATUS_CODE'] = 422
+```
 
 ### Stopping on First Validation Failure
 

flask_sieve/__init__.py

@@ -2,6 +2,12 @@
 from .validator import validate, Validator
 from .exceptions import ValidationException, register_error_handler
 
+
 class Sieve:
-    def __init__(self, app):
+    def __init__(self, app=None):
+        if app is not None:
+            self.init_app(app)
+
+    @staticmethod
+    def init_app(app):
         register_error_handler(app)

flask_sieve/exceptions.py

@@ -1,19 +1,27 @@
 from flask import jsonify
 
+
 class ValidationException(Exception):
     def __init__(self, errors):
         self.errors = errors
 
 
 def register_error_handler(app):
     def validations_error_handler(ex):
-        return jsonify({
-            'success': False,
-            'message': 'Validation error',
+        response = {
+            'message': app.config.get('SIEVE_RESPONSE_MESSAGE', 'Validation error'),
             'errors': ex.errors
-        }), 400
+        }
+
+        if app.config.get('SIEVE_INCLUDE_SUCCESS_KEY'):
+            response['success'] = False
+
+        if app.config.get('SIEVE_RESPONSE_WRAPPER'):
+            response = {app.config.get('SIEVE_RESPONSE_WRAPPER'): response}
+
+        return jsonify(response), app.config.get('SIEVE_INVALID_STATUS_CODE', 400)
+
     app.register_error_handler(
         ValidationException,
         validations_error_handler
     )
-

tests/test_exceptions.py

@@ -18,3 +18,93 @@ def test_error_handler(self):
             )
         self.assertEqual(400, status)
         self.assertIn('Test error', str(response.get_json()))
+
+    def test_configurable_status_code(self):
+        app = Flask(__name__)
+        app.config['SIEVE_INVALID_STATUS_CODE'] = 422
+        register_error_handler(app)
+        self.assertIn(ValidationException, app.error_handler_spec[None][None])
+        errors = {'field': 'Test error'}
+
+        with app.app_context():
+            response, status = app.error_handler_spec[None][None][ValidationException](
+                ValidationException(errors)
+            )
+        self.assertEqual(422, status)
+        self.assertIn('Test error', str(response.get_json()))
+
+    def test_configuring_response_message(self):
+        app = Flask(__name__)
+        msg = "Only Chuck Norris can submit invalid data!"
+        app.config['SIEVE_RESPONSE_MESSAGE'] = msg
+        register_error_handler(app)
+        self.assertIn(ValidationException, app.error_handler_spec[None][None])
+        errors = {'field': 'Test error'}
+
+        with app.app_context():
+            response, status = app.error_handler_spec[None][None][ValidationException](
+                ValidationException(errors)
+            )
+        self.assertEqual(400, status)
+        self.assertIn(msg, str(response.get_json()))
+
+    def test_keeping_success_message(self):
+        app = Flask(__name__)
+        app.config['SIEVE_INCLUDE_SUCCESS_KEY'] = True
+
+        register_error_handler(app)
+        self.assertIn(ValidationException, app.error_handler_spec[None][None])
+        errors = {'field': 'Test error'}
+
+        with app.app_context():
+            response, status = app.error_handler_spec[None][None][ValidationException](
+                ValidationException(errors)
+            )
+        self.assertEqual(400, status)
+        self.assertTrue('success' in response.get_json())
+
+    def test_keeping_removing_message(self):
+        app = Flask(__name__)
+        app.config['SIEVE_INCLUDE_SUCCESS_KEY'] = False
+
+        register_error_handler(app)
+        self.assertIn(ValidationException, app.error_handler_spec[None][None])
+        errors = {'field': 'Test error'}
+
+        with app.app_context():
+            response, status = app.error_handler_spec[None][None][ValidationException](
+                ValidationException(errors)
+            )
+        self.assertEqual(400, status)
+        self.assertFalse('success' in response.get_json())
+
+    def test_wrapping_response_with_data(self):
+        app = Flask(__name__)
+        app.config['SIEVE_RESPONSE_WRAPPER'] = 'data'
+
+        register_error_handler(app)
+        self.assertIn(ValidationException, app.error_handler_spec[None][None])
+        errors = {'field': 'Test error'}
+
+        with app.app_context():
+            response, status = app.error_handler_spec[None][None][ValidationException](
+                ValidationException(errors)
+            )
+        self.assertEqual(400, status)
+        self.assertIn('Test error', str(response.get_json()))
+        self.assertTrue('data' in response.get_json())
+
+    def test_wrapping_response_without_data(self):
+        app = Flask(__name__)
+        register_error_handler(app)
+        self.assertIn(ValidationException, app.error_handler_spec[None][None])
+        errors = {'field': 'Test error'}
+
+        with app.app_context():
+            response, status = app.error_handler_spec[None][None][ValidationException](
+                ValidationException(errors)
+            )
+        self.assertEqual(400, status)
+        self.assertIn('Test error', str(response.get_json()))
+        self.assertFalse('data' in response.get_json())
+        self.assertTrue('errors' in response.get_json())

tests/test_sieve.py

@@ -19,3 +19,19 @@ def test_registers_error_handler(self):
             )
         self.assertEqual(400, status)
         self.assertIn('Test error', str(response.get_json()))
+
+    def test_deferring_registration_of_error_handler(self):
+        app = Flask(__name__)
+        s = Sieve()
+
+        s.init_app(app)
+
+        self.assertIn(ValidationException, app.error_handler_spec[None][None])
+        errors = {'field': 'Test error'}
+
+        with app.app_context():
+            response, status = app.error_handler_spec[None][None][ValidationException](
+                ValidationException(errors)
+            )
+        self.assertEqual(400, status)
+        self.assertIn('Test error', str(response.get_json()))