Simplify deprecated handler.

Author: jdfreder

jupyter_notebook/notebookapp.py

@@ -12,7 +12,6 @@
 import imp
 import importlib
 import io
-import itertools
 import json
 import logging
 import os
@@ -127,36 +126,6 @@ def load_handlers(name):
     name = 'jupyter_notebook.' + name
     mod = __import__(name, fromlist=['default_handlers'])
     return mod.default_handlers
-
-class ShimHandler(FileFindHandler):
-    def validate_absolute_path(self, *args, **kwargs):
-        return super(ShimHandler, self).validate_absolute_path(*args, **kwargs)
-
-    def get_content(self, *args, **kwargs):
-        self.log.warn('Deprecated widget Javascript path /static/widgets/js/*.js was used')
-        
-        # Get the content.  get_content will return either a bytestring
-        # or an iterator of bytestrings, depending on the file.
-        content = super(ShimHandler, self).get_content(*args, **kwargs)
-
-        # Check if something should be prepended.
-        if self.prepend is not None:
-            self.set_header("Content-Length", str(int(self._headers["Content-Length"]) + len(self.prepend)))
-            if isinstance(content, (bytes)): # Bytes
-                content = self.prepend + content
-            else: # Iterator
-                content = itertools.chain([self.prepend], content)
-        return content
-
-def make_shim_handler(log, prepend=None, encoding='utf-8'):
-    """Makes a FileFindHandler capable of prepending content
-    to the files.""" 
-    
-    # If the caller wants something to be prepended, encode it as
-    # the appropriate data type.
-    if prepend is not None:
-        prepend = bytes(prepend, encoding=encoding)    
-    return type('ShimHandler', (ShimHandler, ), {'log': log, 'prepend': prepend})
 
 #-----------------------------------------------------------------------------
 # The Tornado web application
@@ -309,13 +278,24 @@ def _create_widget_shim_handlers(self):
             ipythonwidgets = imp.find_module('ipython_widgets')[1]
             widget_js = os.path.join(ipythonwidgets, 'static', 'widgets')
 
+            class DeprecationHandler(IPythonHandler):
+                def get(self, url_path):
+                    self.set_header("Content-Type", 'text/javascript')
+
+                    # Verify that the file requested exists.
+                    local_file = os.path.join(widget_js, *url_path.split('/'))
+                    if not os.path.isfile(local_file):
+                        self.set_status(404)
+                        self.finish("File doesn't exits")
+
+                    # Read the file and append the warning.
+                    with open(local_file, 'r') as f:
+                        contents = f.read()
+                    self.finish(DEPRECATED_WIDGET_WARNING + contents)
+                    self.log.warn('Deprecated widget Javascript path /static/widgets/js/*.js was used')
             return [(
                 r'/deprecatedwidgets/(.*)', 
-                make_shim_handler(self.log, prepend=DEPRECATED_WIDGET_WARNING), 
-                {
-                    'path': widget_js,
-                    'no_cache_paths': ['/'], # don't cache anything in widgets
-                }
+                DeprecationHandler
             )]
         except: # ipython_widgets is not installed
             class ErrorHandler(IPythonHandler):