Use marshmallow and webargs for parsing and marshaling

app/api/__init__.py

@@ -2,6 +2,7 @@ from flask import Blueprint
 from flask_restful import Api
 from .resources.account import AccountResource
 from .resources.token import TokenResource
+from marshmallow import ValidationError
 
 api_bp = Blueprint('api', __name__)
 api = Api(api_bp)
@@ -9,3 +10,16 @@ api = Api(api_bp)
 # Add resources
 api.add_resource(AccountResource, '/v1/accounts')
 api.add_resource(TokenResource, '/v1/token')
+
+
+@api_bp.errorhandler(ValidationError)
+def handle_validation_error(e):
+    return {'status': 'error', 'message': str(e)}, 422
+
+
+@api_bp.errorhandler(Exception)
+def handle_unknown_errors(e):
+    return ({
+        'status': 'failed',
+        'message': 'Unknown error has occurred! ({0})'.format(str(e))
+        }, 500)

app/api/resources/account.py

@@ -1,38 +1,22 @@
-from flask_restful import Resource, reqparse, abort
+from flask_restful import Resource, abort
+from webargs import fields
+from webargs.flaskparser import use_args
 import app.accounts as accounts
 
 
-def user(user_dict):
-    """
-    Type definition of user object required as a parameter
-
-    Required keys:
-     * username - string
-     * password - string
-     * email    - string
-
-    :returns user dictionary with required keys
-    :rtype dict
-    :raises ValueError if parameter is not dict or is missing required keys
-    """
-    if not isinstance(user_dict, dict):
-        raise ValueError("User should contain username, password and email")
-    if ('username' not in user_dict or
-            'password' not in user_dict or
-            'email' not in user_dict):
-        raise ValueError("User should contain username, password and email")
-    return user_dict
-
-
 class AccountResource(Resource):
-    parser = reqparse.RequestParser(bundle_errors=True)
+    user_args = {
-    parser.add_argument('user', location='json', type=user,
+            'user': fields.Nested({
-                        help='User is not valid. Error: {error_msg}',
+                'username': fields.Str(required=True),
-                        required=True)
+                'email': fields.Email(required=True),
+                'password': fields.Str(required=True)
+            }, required=True, location='json')
+    }
 
-    def post(self):
+    @use_args(user_args)
+    def post(self, args):
         try:
-            args = AccountResource.parser.parse_args()['user']
+            args = args['user']
             success = accounts.create_account(
                     args['username'],
                     args['email'],

app/api/resources/token.py

@@ -1,46 +1,25 @@
-from flask_restful import Resource, reqparse, abort, fields, marshal_with
+from flask_restful import Resource, abort
+from webargs import fields
+from webargs.flaskparser import use_args
 import app.accounts as accounts
 
 
-def user(user_dict):
-    """
-    Type definition of user object required as a parameter
-
-    Required keys:
-     * username - string
-     * password - string
-
-    :returns user dictionary with required keys
-    :rtype dict
-    :raises ValueError if parameter is not dict or is missing required keys
-    """
-    if not isinstance(user_dict, dict):
-        raise ValueError("User should contain username, password and email")
-    if ('username' not in user_dict or
-            'password' not in user_dict):
-        raise ValueError("User should contain username, password and email")
-    return user_dict
-
-
 class TokenResource(Resource):
-    parser = reqparse.RequestParser(bundle_errors=True)
+    user_args = {
-    parser.add_argument('user', location='json', type=user,
+            'user': fields.Nested({
-                        help='User is not valid. Error: {error_msg}',
+                'username': fields.Str(),
-                        required=True)
+                'password': fields.Str()
-
+            }, required=True, location='json')
-    res_fields = {
-            'status': fields.String(default='Success'),
-            'token': fields.String
     }
 
-    @marshal_with(res_fields)
+    @use_args(user_args)
-    def post(self):
+    def post(self, args):
         try:
-            args = TokenResource.parser.parse_args()['user']
+            args = args['user']
             token = accounts.create_token(
                     args['username'],
                     args['password'])
             if token:
-                return {'token': token}, 200
+                return {'status': 'success', 'token': token}, 200
         except ValueError:
             abort(401, message='Invalid credentials', status='error')

requirements.txt

@@ -16,8 +16,10 @@ itsdangerous==0.24
 Jinja2==2.10
 Mako==1.0.7
 MarkupSafe==1.0
+marshmallow==3.0.0b9
 paho-mqtt==1.3.1
 psycopg2==2.7.4
+psycopg2-binary==2.7.4
 pycparser==2.18
 PyJWT==1.4.2
 python-dateutil==2.7.2
@@ -26,4 +28,5 @@ pytz==2018.4
 six==1.11.0
 SQLAlchemy==1.2.7
 typing==3.6.4
+webargs==2.1.0
 Werkzeug==0.14.1