Merge pull request #11978 from Carreau/fix-mime-bokeh

Handle case where the shell does not have arbitrary mimerenderer handler

IPython/core/displaypub.py

@@ -1,138 +1,138 b''
 """An interface for publishing rich data to frontends.
 
 There are two components of the display system:
 
 * Display formatters, which take a Python object and compute the
   representation of the object in various formats (text, HTML, SVG, etc.).
 * The display publisher that is used to send the representation data to the
   various frontends.
 
 This module defines the logic display publishing. The display publisher uses
 the ``display_data`` message type that is defined in the IPython messaging
 spec.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 import sys
 
 from traitlets.config.configurable import Configurable
 from traitlets import List, Dict
 
 # This used to be defined here - it is imported for backwards compatibility
 from .display import publish_display_data
 
 #-----------------------------------------------------------------------------
 # Main payload class
 #-----------------------------------------------------------------------------
 
 
 class DisplayPublisher(Configurable):
     """A traited class that publishes display data to frontends.
 
     Instances of this class are created by the main IPython object and should
     be accessed there.
     """
 
     def __init__(self, shell=None, *args, **kwargs):
         self.shell = shell
         super().__init__(*args, **kwargs)
 
     def _validate_data(self, data, metadata=None):
         """Validate the display data.
 
         Parameters
         ----------
         data : dict
             The formata data dictionary.
         metadata : dict
             Any metadata for the data.
         """
 
         if not isinstance(data, dict):
             raise TypeError('data must be a dict, got: %r' % data)
         if metadata is not None:
             if not isinstance(metadata, dict):
                 raise TypeError('metadata must be a dict, got: %r' % data)
 
     # use * to indicate transient, update are keyword-only
     def publish(self, data, metadata=None, source=None, *, transient=None, update=False, **kwargs) -> None:
         """Publish data and metadata to all frontends.
 
         See the ``display_data`` message in the messaging documentation for
         more details about this message type.
 
         The following MIME types are currently implemented:
 
         * text/plain
         * text/html
         * text/markdown
         * text/latex
         * application/json
         * application/javascript
         * image/png
         * image/jpeg
         * image/svg+xml
 
         Parameters
         ----------
         data : dict
             A dictionary having keys that are valid MIME types (like
             'text/plain' or 'image/svg+xml') and values that are the data for
             that MIME type. The data itself must be a JSON'able data
             structure. Minimally all data should have the 'text/plain' data,
             which can be displayed by all frontends. If more than the plain
             text is given, it is up to the frontend to decide which
             representation to use.
         metadata : dict
             A dictionary for metadata related to the data. This can contain
             arbitrary key, value pairs that frontends can use to interpret
             the data.  Metadata specific to each mime-type can be specified
             in the metadata dict with the same mime-type keys as
             the data itself.
         source : str, deprecated
             Unused.
         transient: dict, keyword-only
             A dictionary for transient data.
             Data in this dictionary should not be persisted as part of saving this output.
             Examples include 'display_id'.
         update: bool, keyword-only, default: False
             If True, only update existing outputs with the same display_id,
             rather than creating a new output.
         """
 
         handlers = {}
         if self.shell is not None:
-            handlers = self.shell.mime_renderers
+            handlers = getattr(self.shell, 'mime_renderers', {})
 
         for mime, handler in handlers.items():
             if mime in data:
                 handler(data[mime], metadata.get(mime, None))
                 return
 
         if 'text/plain' in data:
             print(data['text/plain'])
 
     def clear_output(self, wait=False):
         """Clear the output of the cell receiving output."""
         print('\033[2K\r', end='')
         sys.stdout.flush()
         print('\033[2K\r', end='')
         sys.stderr.flush()
 
 
 class CapturingDisplayPublisher(DisplayPublisher):
     """A DisplayPublisher that stores"""
     outputs = List()
 
     def publish(self, data, metadata=None, source=None, *, transient=None, update=False):
         self.outputs.append({'data':data, 'metadata':metadata,
                              'transient':transient, 'update':update})
 
     def clear_output(self, wait=False):
         super(CapturingDisplayPublisher, self).clear_output(wait)
 
         # empty the list, *do not* reassign a new list
         self.outputs.clear()