Fix Google Colab Jupyter Notebooks rendering by excluding widgets (#7271

)

Co-authored-by: Donny Wong <donnywong@cs.toronto.edu>

Changelog.md

@@ -17,6 +17,7 @@
 - Disable editable fields in assignment criterion when criterion is released (#7264)
 - Fix Marks Spreadsheet csv bug of showing incorrect marks (#7257)
 - Fix incorrect inclusion of course parameter in LtiSyncJob (#7258)
+- Fix Google Colab Jupyter Notebooks rendering by excluding widgets (#7271)
 
 ### 🔧 Internal changes
 

app/controllers/submissions_controller.rb

@@ -1,3 +1,5 @@
+require 'json'
+
 class SubmissionsController < ApplicationController
   include SubmissionsHelper
   include RepositoryHelper
@@ -948,6 +950,11 @@ def notebook_to_html(file_contents, unique_path, type)
           '--template', 'markus-html-template'
         ]
       end
+      file_contents = JSON.parse(file_contents)
+      if file_contents['metadata'].key?('widgets')
+        file_contents['metadata'].delete('widgets')
+      end
+      file_contents = JSON.generate(file_contents)
       _stdout, stderr, status = Open3.capture3(*args, stdin_data: file_contents)
       return "#{I18n.t('submissions.cannot_display')}<br/><br/>#{stderr.lines.last}" unless status.exitstatus.zero?
 

spec/controllers/submissions_controller_spec.rb

@@ -1697,6 +1697,19 @@
         it_behaves_like 'notebook content'
       end
 
+      context 'a jupyter-notebook file with widgets',
+              skip: Rails.application.config.nbconvert_enabled ? false : 'nbconvert dependencies not installed' do
+        render_views
+        let(:filename) { 'example_widgets.ipynb' }
+
+        it 'renders without widgets' do
+          subject
+          expect(response.body).not_to include("KeyError: 'state'")
+        end
+
+        it_behaves_like 'notebook content'
+      end
+
       context 'an rmarkdown file' do
         let(:filename) { 'example.Rmd' }
 

spec/fixtures/files/example_widgets.ipynb

@@ -0,0 +1,52 @@
+{
+  "nbformat": 4,
+  "nbformat_minor": 0,
+  "metadata": {
+    "colab": {
+      "provenance": []
+    },
+    "kernelspec": {
+      "name": "python3",
+      "display_name": "Python 3"
+    },
+    "language_info": {
+      "name": "python"
+    },
+    "widgets": {
+      "application/vnd.jupyter.widget-state+json": {
+      }
+    }
+  },
+  "cells": [
+    {
+      "cell_type": "code",
+      "source": [
+      ],
+      "metadata": {
+        "id": "wekaZO6DYWz6",
+        "colab": {
+          "base_uri": "https://localhost:8080/",
+          "height": 1000
+        },
+        "outputId": "990f2494-5ca0-442f-ba8d-f7a31bd463e4"
+      },
+      "execution_count": 17,
+      "outputs": [
+        {
+          "output_type": "display_data",
+          "data": {
+            "text/plain": [
+              "Training:   0%|          | 0/1000 [00:00<?, ?it/s]"
+            ],
+            "application/vnd.jupyter.widget-view+json": {
+              "version_major": 2,
+              "version_minor": 0,
+              "model_id": "92b45d943b9e4c83b50bb2c83505e80d"
+            }
+          },
+          "metadata": {}
+        }
+      ]
+    }
+  ]
+}