Extend ValidationException (#17)

Author: trizz

CHANGELOG.md

@@ -7,6 +7,11 @@ Updates should follow the [Keep a CHANGELOG](http://keepachangelog.com/) princip
 ## [Unreleased]
 [Compare 2.0.0 - Unreleased](https://github.com/exonet/exonet-api-python/compare/2.0.0...master)
 
+## [2.1.0](https://github.com/exonet/exonet-api-python/releases/tag/2.1.0) - 2019-11-19
+[Compare 2.0.0 - 2.1.0](https://github.com/exonet/exonet-api-python/compare/2.0.0...2.1.0)
+### Changed
+- Extend the `ValidationException` to contain all returned validation errors. See the [docs](./docs/error_handling.md) for more information.
+
 ## [2.0.0](https://github.com/exonet/exonet-api-python/releases/tag/2.0.0) - 2019-09-19
 [Compare 1.0.0 - 2.0.0](https://github.com/exonet/exonet-api-python/compare/1.0.0...2.0.0)
 ### Breaking

docs/error_handling.md

@@ -50,6 +50,28 @@ This will output the request body where the details of the error can be found:
 requests.exceptions.HTTPError: 400 Client Error: Bad Request for url: https://api.exonet.nl/certificates/invalidID
 ```
 
+## Handling validation errors
+When there are validation errors, an extended version of the HTTPError as describe above is returned. It contains the
+validation errors grouped per field, accessible with the `get_failed_validations` method:
+
+```python
+# Assuming 'record' is an already constructed variable.
+try:
+    created_item = record.post()
+except ValidationException as err:
+    # Print validation errors.
+    print('{}'.format(err))
+    validation_errors = err.get_failed_validations()
+    for field in validation_errors:
+        for error in validation_errors[field]:
+            print('{}: {}'.format(field, error))
+except HTTPError as err:
+    # Print all other errors.
+    print('HTTP Error: {}'.format(err))
+``` 
+
+Validation errors that are not related to a field are keyed with `generic`.
+
 ---
 
 [Back to the index](index.md)

exonetapi/exceptions/ValidationException.py

@@ -1,27 +1,35 @@
 from requests.exceptions import HTTPError
+
 """
 Http validation exception.
 """
+
+
 class ValidationException(HTTPError):
     def __init__(self, response):
         # Collect validation errors as list of strings.
-        validationErrors = []
+        self.validation_errors = {}
 
         # Loop errors.
         for error in response.json()['errors']:
             # Handle only validation errors.
             if error['status'] == 422:
-                # Use the error details as error message.
-                errorMessage = error['detail']
-
-                # If the error has variables available, use those.
-                if len(error['variables']) >= 3:
-                    errorMessage = "Field: %s, failed rule: %s(%s)." % (
-                        error['variables']['field'],
-                        error['variables']['rule'],
-                        error['variables']['rule_requirement']
-                    )
-                # Add this error message to the list of errors.
-                validationErrors.append(errorMessage)
-
-        HTTPError.__init__(self, ' '.join(validationErrors), response=response)
+                field = 'generic'
+                if 'field' in error['variables']:
+                    field = error['variables']['field'] or error['detail']
+
+                if field not in self.validation_errors:
+                    self.validation_errors[field] = []
+
+                self.validation_errors[field].append(error['detail'])
+
+        if self.validation_errors.__len__() == 1:
+            validation_error = 'There is {} validation error.'
+        else:
+            validation_error = 'There are {} validation errors.'
+
+        HTTPError.__init__(self, validation_error.format(self.validation_errors.__len__()),
+                           response=response)
+
+    def get_failed_validations(self):
+        return self.validation_errors

tests/exceptions/testValidationException.py

@@ -21,8 +21,7 @@ def test_no_errors(self):
         v = ValidationException(response)
         response.json.assert_called_once()
 
-        # Assert no validation exception message is set.
-        self.assertEqual(v.args[0], '')
+        self.assertEqual(v.args[0], 'There are 0 validation errors.')
 
     def test_one_error(self):
         # Construct the request response.
@@ -49,10 +48,8 @@ def test_one_error(self):
 
         response.json.assert_called_once()
         # Make sure the right message is set.
-        self.assertEqual(
-            v.args[0],
-            'Field: start_date, failed rule: iso8601-date(Date must be in iso8601 format).'
-        )
+        self.assertEqual(v.args[0], 'There is 1 validation error.')
+        self.assertEqual(v.get_failed_validations()['start_date'][0], 'Detailed error message')
 
     def test_twoErrors(self):
         # Construct the request response.
@@ -88,11 +85,11 @@ def test_twoErrors(self):
         v = ValidationException(response)
 
         response.json.assert_called_once()
+        failed = v.get_failed_validations()
         # Make sure the right message is set.
-        self.assertEqual(
-            v.args[0],
-            'Field: data.end_date, failed rule: Required(). The provided data is invalid.'
-        )
+        self.assertEqual(v.args[0], 'There are 2 validation errors.')
+        self.assertEqual(failed['data.end_date'][0], 'The data.end_date field is required.')
+        self.assertEqual(failed['generic'][0], 'The provided data is invalid.')
 
     def test_otherErrors(self):
         # Construct the request response.
@@ -113,7 +110,7 @@ def test_otherErrors(self):
 
         response.json.assert_called_once()
         # Make sure there is no validation exception message.
-        self.assertEqual(v.args[0], '')
+        self.assertEqual(v.args[0], 'There are 0 validation errors.')
 
 
 if __name__ == '__main__':