Merge pull request #5 from aplmicrons/custom_err

Custom error handler

Author: sandyhider

django/bosscore/error.py

@@ -46,6 +46,7 @@ class ErrorCodes(IntEnum):
     MISSING_PERMISSION = 3001
     UNRECOGNIZED_PERMISSION = 3002
     INGEST_NOT_CREATOR = 3003
+    ACCESS_DENIED_UNKNOWN = 3004        # User may not even be logged in. 
 
     # Database errors
     RESOURCE_NOT_FOUND = 4000

django/bosscore/renderer_helper.py

@@ -0,0 +1,70 @@
+# Copyright 2016 The Johns Hopkins University Applied Physics Laboratory
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from bosscore.error import ErrorCodes
+from rest_framework.renderers import JSONRenderer
+
+def check_for_403(fcn):
+    """Decorator to check renderer_context for a 403 response.
+
+    Args:
+        fcn (function): A custom BaseRenderer.render() implementation..
+
+    Returns:
+        (function): Wraps given function with one that checks for a 403 status.
+    """
+
+    def wrapper(*args, **kwargs):
+        """Return a JSON response if a 403 found.
+
+        Executes the custom renderer if no 403 status code found.
+
+        Args:
+
+        Returns:
+            (BaseRenderer)
+        """
+
+        # renderer_context is the 4th argument if not specified by keyword.
+        if len(args) < 4 and kwargs is None:
+            return fcn(*args, **kwargs)
+
+        renderer_context = None
+        if len(args) >= 4:
+            renderer_context = args[3]
+        elif kwargs is not None and 'renderer_context' in kwargs:
+            renderer_context = kwargs['renderer_context']
+
+        if renderer_context is None:
+            return fcn(*args, **kwargs)
+
+        # Check for presense of a Response object.
+        if 'response' not in renderer_context:
+            return fcn(*args, **kwargs)
+
+        # Have a response, check for 403.
+        if renderer_context['response'].status_code == 403:
+            renderer_context['response']['Content-Type'] = 'application/json'
+            obj = args[0]
+            obj.media_type = 'application/json'
+            obj.format = 'json'
+            err_msg = {"status": 403, "message": "Access denied, are you logged in?",
+                       "code": ErrorCodes.ACCESS_DENIED_UNKNOWN}
+            jr = JSONRenderer()
+            return jr.render(err_msg, 'application/json', renderer_context)
+
+        return fcn(*args, **kwargs)
+
+    return wrapper
+

django/bossspatialdb/renderers.py

@@ -20,6 +20,7 @@
 import io
 from PIL import Image
 
+from bosscore.renderer_helper import check_for_403
 
 class BloscPythonRenderer(renderers.BaseRenderer):
     """ A DRF renderer for a blosc encoded cube of data using the numpy interface
@@ -31,6 +32,7 @@ class BloscPythonRenderer(renderers.BaseRenderer):
     charset = None
     render_style = 'binary'
 
+    @check_for_403
     def render(self, data, media_type=None, renderer_context=None):
 
         if not data["data"].data.flags['C_CONTIGUOUS']:
@@ -52,8 +54,18 @@ class BloscRenderer(renderers.BaseRenderer):
     charset = None
     render_style = 'binary'
 
+    @check_for_403
     def render(self, data, media_type=None, renderer_context=None):
 
+        if renderer_context['response'].status_code == 403:
+            renderer_context["accepted_media_type"] = 'application/json'
+            self.media_type = 'application/json'
+            self.format = 'json'
+            err_msg = {"status": 403, "message": "Access denied, are you logged in?",
+                       "code": 2005}
+            jr = JSONRenderer()
+            return jr.render(err_msg, 'application/json', renderer_context)
+
         if not data["data"].data.flags['C_CONTIGUOUS']:
             data["data"].data = np.ascontiguousarray(data["data"].data, dtype=data["data"].data.dtype)
 
@@ -75,6 +87,7 @@ class NpygzRenderer(renderers.BaseRenderer):
     charset = None
     render_style = 'binary'
 
+    @check_for_403
     def render(self, data, media_type=None, renderer_context=None):
 
         if not data["data"].data.flags['C_CONTIGUOUS']:
@@ -106,6 +119,7 @@ class JpegRenderer(renderers.BaseRenderer):
     charset = None
     render_style = 'binary'
 
+    @check_for_403
     def render(self, data, media_type=None, renderer_context=None):
 
         # Return data, squeezing time dimension as this only works with 3D data
@@ -115,6 +129,7 @@ def render(self, data, media_type=None, renderer_context=None):
         else:
             # This appears to contain time data. Error out
             renderer_context["response"].status_code = 400
+            renderer_context['response']['Content-Type'] = 'application/json'
             renderer_context["accepted_media_type"] = 'application/json'
             self.media_type = 'application/json'
             self.format = 'json'
@@ -126,6 +141,7 @@ def render(self, data, media_type=None, renderer_context=None):
         if renderer_context['view'].bit_depth != 8:
             # This renderer only works on uint8 data
             renderer_context["response"].status_code = 400
+            renderer_context['response']['Content-Type'] = 'application/json'
             renderer_context["accepted_media_type"] = 'application/json'
             self.media_type = 'application/json'
             self.format = 'json'

django/bosstiles/renderers.py

@@ -13,6 +13,8 @@
 # limitations under the License.
 import io
 from rest_framework import renderers
+from rest_framework.renderers import JSONRenderer
+from bosscore.renderer_helper import check_for_403
 
 
 class PNGRenderer(renderers.BaseRenderer):
@@ -23,6 +25,7 @@ class PNGRenderer(renderers.BaseRenderer):
     charset = None
     render_style = 'binary'
 
+    @check_for_403
     def render(self, data, media_type=None, renderer_context=None):
         file_obj = io.BytesIO()
         data.save(file_obj, "PNG")
@@ -38,6 +41,7 @@ class JPEGRenderer(renderers.BaseRenderer):
     charset = None
     render_style = 'binary'
 
+    @check_for_403
     def render(self, data, media_type=None, renderer_context=None):
         file_obj = io.BytesIO()
         data.save(file_obj, "JPEG")