first pass at nteract support

Author: chriddyp

CHANGELOG.md

@@ -3,6 +3,10 @@ All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
+### Added
+- Support for rendering plots in [nteract](https://nteract.io/)!
+  See [https://github.com/nteract/nteract/pull/662](https://github.com/nteract/nteract/pull/662)
+  for the associated PR in nteract.
 
 ### Added
 - `memoize` decorator added to `plotly.utils`

plotly/offline/offline.py

@@ -273,7 +273,7 @@ def iplot(figure_or_data, show_link=True, link_text='Export to plot.ly',
           validate=True, image=None, filename='plot_image', image_width=800,
           image_height=600):
     """
-    Draw plotly graphs inside an IPython notebook without
+    Draw plotly graphs inside an IPython or Jupter notebook without
     connecting to an external server.
     To save the chart to Plotly Cloud or Plotly Enterprise, use
     `plotly.plotly.iplot`.
@@ -335,7 +335,33 @@ def iplot(figure_or_data, show_link=True, link_text='Export to plot.ly',
         figure_or_data, config, validate, '100%', 525, True
     )
 
-    ipython_display.display(ipython_display.HTML(plot_html))
+    figure = tools.return_figure_from_figure_or_data(figure_or_data, validate)
+
+    # Display 2 versions of the figure:
+    # - The raw HTML is the "old-school" style - we just throw in a JS script
+    #   inside the cell. This works for a lot of environments but some JS is
+    #   stripped out in some rendering environments / platforms like
+    #   GitHub, nteract, and eventually Plotly
+    # - The custom `mime-types` is the new-school way. nteract supports
+    #   rendering plotly graphs this way (see https://github.com/nteract/nteract/pull/662)
+    #   and others will hopefully follow suite.
+    # Both of these bundles will be saved as part of the notebook. The renderer
+    # will choose which one to render. So 'text/html' is like a fallback for
+    # any environment that doesn't have the 'application/json+plotly.v1'
+    # renderer available.
+    # The bummer is that we're injecting the figure JSON in here twice, so
+    # notebooks that are pretty big are about to get a lot bigger.
+    # The upside is that we're dropping any compatability for older notebook
+    # versions
+    data = _json.loads(_json.dumps(figure['data'],
+                                   cls=plotly.utils.PlotlyJSONEncoder))
+    layout = _json.loads(_json.dumps(figure.get('layout', {}),
+                                     cls=plotly.utils.PlotlyJSONEncoder))
+    display_bundle = {
+        'application/vnd.plotly.v1+json': {'data': data, 'layout': layout},
+        'text/html': plot_html
+    }
+    ipython_display.display(display_bundle, raw=True)
 
     if image:
         if image not in __IMAGE_FORMATS: