Merge pull request #487 from plotly/bare-exceptions

Bare exceptions

Author: Shammamah Hossain

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.33.0 - 2018-12-10
+## Added
+- Added specific Dash exception types to replace generic exceptions (InvalidIndexException, DependencyException, ResourceException) [#487](https://github.com/plotly/dash/pull/487)
+
 ## 0.32.2 - 2018-12-09
 ## Fixed
 - Fix typo in missing events/inputs error message [#485](https://github.com/plotly/dash/pull/485)

dash/dash.py

@@ -275,7 +275,7 @@ def _layout_value(self):
     def layout(self, value):
         if (not isinstance(value, Component) and
                 not isinstance(value, collections.Callable)):
-            raise Exception(
+            raise exceptions.NoLayoutException(
                 ''
                 'Layout must be a dash component '
                 'or a function that returns '
@@ -301,7 +301,7 @@ def index_string(self, value):
         )
         missing = [missing for check, missing in checks if not check]
         if missing:
-            raise Exception(
+            raise exceptions.InvalidIndexException(
                 'Did you forget to include {} in your index string ?'.format(
                     ', '.join('{%' + x + '%}' for x in missing)
                 )
@@ -475,14 +475,14 @@ def _generate_meta_html(self):
     # Serve the JS bundles for each package
     def serve_component_suites(self, package_name, path_in_package_dist):
         if package_name not in self.registered_paths:
-            raise exceptions.InvalidResourceError(
+            raise exceptions.DependencyException(
                 'Error loading dependency.\n'
                 '"{}" is not a registered library.\n'
                 'Registered libraries are: {}'
                 .format(package_name, list(self.registered_paths.keys())))
 
         elif path_in_package_dist not in self.registered_paths[package_name]:
-            raise exceptions.InvalidResourceError(
+            raise exceptions.DependencyException(
                 '"{}" is registered but the path requested is not valid.\n'
                 'The path requested: "{}"\n'
                 'List of registered paths: {}'
@@ -546,7 +546,7 @@ def index(self, *args, **kwargs):  # pylint: disable=unused-argument
 
         if missing:
             plural = 's' if len(missing) > 1 else ''
-            raise Exception(
+            raise exceptions.InvalidIndexException(
                 'Missing element{pl} {ids} in index.'.format(
                     ids=', '.join(missing),
                     pl=plural

dash/exceptions.py

@@ -64,3 +64,15 @@ class InvalidConfig(DashException):
 
 class InvalidResourceError(DashException):
     pass
+
+
+class InvalidIndexException(DashException):
+    pass
+
+
+class DependencyException(DashException):
+    pass
+
+
+class ResourceException(DashException):
+    pass

dash/resources.py

@@ -3,6 +3,7 @@
 import os
 
 from .development.base_component import ComponentRegistry
+from . import exceptions
 
 
 # pylint: disable=old-style-class
@@ -47,7 +48,7 @@ def _filter_resources(self, all_resources, dev_bundles=False):
                 )
                 continue
             else:
-                raise Exception(
+                raise exceptions.ResourceException(
                     '{} does not have a '
                     'relative_package_path, absolute_path, or an '
                     'external_url.'.format(

dash/version.py

@@ -1 +1 @@
-__version__ = '0.32.2'
+__version__ = '0.33.0'