add basic validation support

api/core.py

@@ -2,6 +2,7 @@ from flask import Flask, jsonify, Response, request
 from flask_sqlalchemy import SQLAlchemy
 from api.extensions.esales import Esales
 from api.helpers import check_api_key
+from api.validators import ValidationError
 
 db = SQLAlchemy()
 esales = Esales()
@@ -15,8 +16,16 @@ def create_app(config_name='config'):
 
     # register errors handlers
     @app.errorhandler(404)
-    def on_404(e):
-        return jsonify(dict(error='Not found')), 404
+    def on_404(error):
+        response = jsonify({'status': 404, 'message': 'The requested resource was not found'})
+        response.status_code = 404
+        return response
+
+    @app.errorhandler(ValidationError)
+    def on_validation_error(error):
+        response = jsonify({'status': 400, 'message': error.message})
+        response.status_code = 400
+        return response
 
     # register blueprints
     from api.views import server, designers, categories