Improve error handling

Author: rliebz

dataverse/__init__.py

@@ -1,6 +1,4 @@
 from connection import Connection
 from dataverse import Dataverse
 from dataset import Dataset
-from file import DataverseFile
-
-from utils import DataverseException
+from file import DataverseFile

dataverse/connection.py

@@ -2,6 +2,7 @@
 import requests
 
 from dataverse import Dataverse
+from exceptions import DataverseError, UnauthorizedError
 from utils import get_elements, is_not_root_dataverse
 
 
@@ -32,13 +33,18 @@ def has_api_key(self):
 
     def connect(self):
         resp = requests.get(self.sd_uri, auth=self.auth)
-        self.status = resp.status_code
-        self.connected = True if self.status == 200 else False
+
+        if resp.status_code == 403:
+            raise UnauthorizedError('The credentials provided are invalid.')
+        elif resp.status_code != 200:
+            raise DataverseError('Could not connect to the Dataverse')
+
+        self.connected = True
         self.service_document = etree.XML(resp.content)
 
-    def get_dataverses(self, allow_root=False):
-        # Get latest dataverse information
-        self.connect()
+    def get_dataverses(self, refresh=False, allow_root=False):
+        if refresh:
+            self.connect()
 
         collections = get_elements(
             self.service_document[0],

dataverse/dataset.py

@@ -5,12 +5,10 @@
 from lxml import etree
 import requests
 
+from exceptions import DataverseError, MethodNotAllowedError, NoContainerError
 from file import DataverseFile
 from settings import SWORD_BOOTSTRAP
-from utils import (
-    get_element, get_elements, DataverseException, get_files_in_path,
-    add_field,
-)
+from utils import get_element, get_elements, get_files_in_path, add_field
 
 
 class Dataset(object):
@@ -93,7 +91,7 @@ def get_entry(self, refresh=False):
         resp = requests.get(self.edit_uri, auth=self.connection.auth)
 
         if resp.status_code != 200:
-            raise DataverseException('Atom entry could not be retrieved.')
+            raise DataverseError('Atom entry could not be retrieved.')
 
         entry_string = resp.content
         self._entry = etree.XML(entry_string)
@@ -103,8 +101,8 @@ def get_statement(self, refresh=False):
         if not refresh and self._statement:
             return self._statement
 
-        if not self.connection:
-            raise DataverseException('This dataset has not been added to a Dataverse.')
+        if not self.dataverse:
+            raise NoContainerError('This dataset has not been added to a Dataverse.')
 
         if not self.statement_uri:
             # Try to find statement uri without a request to the server
@@ -127,7 +125,7 @@ def get_statement(self, refresh=False):
         resp = requests.get(self.statement_uri, auth=self.connection.auth)
 
         if resp.status_code != 200:
-            raise DataverseException('Statement could not be retrieved.')
+            raise DataverseError('Statement could not be retrieved.')
 
         self._statement = resp.content
         return self._statement
@@ -228,14 +226,14 @@ def publish(self):
         )
 
         if resp.status_code != 200:
-            raise DataverseException('The Dataverse could not be published.')
+            raise DataverseError('The Dataverse could not be published.')
 
         receipt = resp.content
         self._refresh(receipt=receipt)
 
     def delete_file(self, dataverse_file):
         if dataverse_file.is_published:
-            raise DataverseException(
+            raise MethodNotAllowedError(
                 'Published versions of files cannot be deleted.'
             )
 
@@ -245,7 +243,7 @@ def delete_file(self, dataverse_file):
         )
 
         if resp.status_code != 204:
-            raise DataverseException('The file could not be deleted.')
+            raise DataverseError('The file could not be deleted.')
 
     def delete_all_files(self):
         for f in self.get_files():

dataverse/dataverse.py

@@ -1,7 +1,8 @@
 import requests
 
 from dataset import Dataset
-from utils import get_element, get_elements, DataverseException, sanitize
+from exceptions import DataverseError, InsufficientMetadataError, MethodNotAllowedError
+from utils import get_element, get_elements, sanitize
 
 
 class Dataverse(object):
@@ -49,16 +50,16 @@ def publish(self):
         )
 
         if resp.status_code != 200:
-            raise DataverseException('The Dataverse could not be published.')
+            raise DataverseError('The Dataverse could not be published.')
 
     def add_dataset(self, dataset):
 
         if get_element(dataset._entry, 'title', 'dcterms') is None:
-            raise DataverseException('This dataset must have a title.')
+            raise InsufficientMetadataError('This dataset must have a title.')
         if get_element(dataset._entry, 'description', 'dcterms') is None:
-            raise DataverseException('This dataset must have a description.')
+            raise InsufficientMetadataError('This dataset must have a description.')
         if get_element(dataset._entry, 'creator', 'dcterms') is None:
-            raise DataverseException('This dataset must have an author.')
+            raise InsufficientMetadataError('This dataset must have an author.')
 
         resp = requests.post(
             self.collection.get('href'),
@@ -68,23 +69,23 @@ def add_dataset(self, dataset):
         )
 
         if resp.status_code != 201:
-            raise DataverseException('This dataset could not be added.')
+            raise DataverseError('This dataset could not be added.')
 
         dataset.dataverse = self
         dataset._refresh(receipt=resp.content)
 
     def delete_dataset(self, dataset):
 
         if dataset._state == 'DELETED' or dataset._state == 'DEACCESSIONED':
-            raise DataverseException('This dataset has already been deleted.')
+            return
 
         resp = requests.delete(
             dataset.edit_uri,
             auth=self.connection.auth,
         )
         if resp.status_code == 405:
-            raise DataverseException('Published studies can only be deleted '
-                'from the GUI. For more information, please refer to '
+            raise MethodNotAllowedError('Published studies can only be '
+                'deleted from the GUI. For more information, please refer to '
                 'https://github.com/IQSS/dataverse/issues/778')
 
         dataset._state = 'DEACCESSIONED'

dataverse/exceptions.py

@@ -0,0 +1,23 @@
+class DataverseError(Exception):
+    """Base exception class for Dataverse-related error."""
+    pass
+
+
+class UnauthorizedError(DataverseError):
+    """Raised if a user provides invalid credentials."""
+    pass
+
+
+class InsufficientMetadataError(DataverseError):
+    """Raised if more metadata is required."""
+    pass
+
+
+class MethodNotAllowedError(DataverseError):
+    """Raised if the attempted method is not allowed"""
+    pass
+
+
+class NoContainerError(DataverseError):
+    """Raised if a dataset attempts to access the server before it is added to a Dataverse"""
+    pass

dataverse/file.py

@@ -1,6 +1,7 @@
 import urlparse
 
-from utils import DataverseException, get_element, sanitize
+from exceptions import InsufficientMetadataError
+from utils import get_element, sanitize
 
 
 class DataverseFile(object):
@@ -21,7 +22,7 @@ def __init__(self, name, dataset, edit_media_uri=None, download_url=None):
             self.download_url = download_url
             self.id = download_url.split('=')[-1]
         else:
-            raise DataverseException(
+            raise InsufficientMetadataError(
                 'Files must have an edit media uri or download url.'
             )
 

dataverse/test/test_dataverse.py

@@ -4,8 +4,9 @@
 logging.basicConfig(level=logging.ERROR)
 
 # local modules
-from dataverse.dataset import Dataset
 from dataverse.connection import Connection
+from dataverse.dataset import Dataset
+from dataverse.exceptions import DataverseError
 from dataverse.settings import DEFAULT_TOKEN, DEFAULT_HOST
 from dataverse.test.config import PICS_OF_CATS_DATASET, ATOM_DATASET
 from dataverse import utils
@@ -97,8 +98,8 @@ def setUpClass(self):
         print "Getting Dataverse"
         dataverses = self.dvc.get_dataverses()
         if not dataverses:
-            raise utils.DataverseException(
-                'You must have a published Dataverse to run these tests.'
+            raise DataverseError(
+                'You must have a Dataverse to run these tests.'
             )
 
         self.dv = dataverses[0]

dataverse/utils.py

@@ -6,10 +6,6 @@
 from settings import SWORD_NAMESPACE, REPLACEMENT_DICT, UNIQUE_FIELDS
 
 
-class DataverseException(Exception):
-    pass
-
-
 def is_not_root_dataverse(collection):
     col_alias = collection.attrib['href'].split('/')[-1]
     # Root dataverse may be named differently per host