From 57e8250619e146a99bb1eaff77d2d1a719b0445b Mon Sep 17 00:00:00 2001
From: Brian Jacobel <bjacobel@gmail.com>
Date: Mon, 13 Mar 2017 18:21:03 -0400
Subject: [PATCH] Webpack in LMS

---
 .babelrc                                      | 21 +++++++
 .gitignore                                    |  2 +
 .../templates/static_content.html             | 20 +++++++
 lms/envs/common.py                            | 11 ++++
 .../course_experience/js/CourseOutline.js     | 32 ++++++++++
 .../js/course_outline_factory.js              | 40 -------------
 .../course-outline-fragment.html              |  8 +--
 package.json                                  | 11 +++-
 requirements/edx/base.txt                     |  1 +
 webpack.config.js                             | 58 +++++++++++++++++++
 10 files changed, 159 insertions(+), 45 deletions(-)
 create mode 100644 .babelrc
 create mode 100644 openedx/features/course_experience/static/course_experience/js/CourseOutline.js
 delete mode 100644 openedx/features/course_experience/static/course_experience/js/course_outline_factory.js
 create mode 100644 webpack.config.js

diff --git a/.babelrc b/.babelrc
new file mode 100644
index 0000000000..e1122c2c6b
--- /dev/null
+++ b/.babelrc
@@ -0,0 +1,21 @@
+{
+  "presets": [
+    ["env", {
+      "targets": {
+        "browsers": [
+          "last 2 versions",
+          "IE >= 11"
+        ]
+      },
+      "useBuiltIns": true,
+      "modules": false,
+      "exclude": [
+        "transform-regenerator"
+      ]
+    }],
+    "react"
+  ],
+  "plugins": [
+    "transform-object-rest-spread"
+  ]
+}
diff --git a/.gitignore b/.gitignore
index ff702a8fe6..f50ad217f3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -95,6 +95,8 @@ lms/static/css/
 lms/static/certificates/css/
 cms/static/css/
 common/static/common/js/vendor/
+common/static/bundles
+webpack-stats.json
 
 ### Styling generated from templates
 lms/static/sass/*.css
diff --git a/common/djangoapps/pipeline_mako/templates/static_content.html b/common/djangoapps/pipeline_mako/templates/static_content.html
index 76282a8c4d..f15fcf596a 100644
--- a/common/djangoapps/pipeline_mako/templates/static_content.html
+++ b/common/djangoapps/pipeline_mako/templates/static_content.html
@@ -85,6 +85,26 @@ engine = Engine(dirs=settings.DEFAULT_TEMPLATE_ENGINE['DIRS'])
 source, template_path = Loader(engine).load_template_source(path)
 %>${source | n, decode.utf8}</%def>
 
+<%def name="webpack(entry)">
+    <%doc>
+        Loads Javascript onto your page from a Webpack-generated bundle.
+        Uses the Django template engine because our webpack loader only provides template tags for Jinja and Django.
+    </%doc>
+    <%
+        from django.template import Template, Context
+        return Template("""
+            {% load render_bundle from webpack_loader %}
+            {% render_bundle entry %}
+            <script type="text/javascript">
+                {% autoescape off %}{{ body }}{% endautoescape %}
+            </script>
+        """).render(Context({
+            'entry': entry,
+            'body': capture(caller.body)
+        }))
+    %>
+</%def>
+
 <%def name="require_module(module_name, class_name)">
     <%doc>
       Loads Javascript onto your page synchronously.
diff --git a/lms/envs/common.py b/lms/envs/common.py
index cf4fed8cc5..d21f589e94 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -1752,6 +1752,16 @@ REQUIRE_JS_PATH_OVERRIDES = {
     'hls': 'common/js/vendor/hls.js'
 }
 
+########################## DJANGO WEBPACK LOADER ##############################
+
+WEBPACK_LOADER = {
+    'DEFAULT': {
+        'BUNDLE_DIR_NAME': 'bundles/',
+        'STATS_FILE': os.path.join(REPO_ROOT, 'webpack-stats.json'),
+    }
+}
+
+
 ########################## DJANGO DEBUG TOOLBAR ###############################
 
 # We don't enable Django Debug Toolbar universally, but whenever we do, we want
@@ -1950,6 +1960,7 @@ INSTALLED_APPS = (
     'edxmako',
     'pipeline',
     'static_replace',
+    'webpack_loader',
 
     # For user interface plugins
     'web_fragments',
diff --git a/openedx/features/course_experience/static/course_experience/js/CourseOutline.js b/openedx/features/course_experience/static/course_experience/js/CourseOutline.js
new file mode 100644
index 0000000000..88fca6904e
--- /dev/null
+++ b/openedx/features/course_experience/static/course_experience/js/CourseOutline.js
@@ -0,0 +1,32 @@
+import * as constants from 'edx-ui-toolkit/src/js/utils/constants';
+import * as Logger from logger;
+
+export class CourseOutline {
+  constructor(root) {
+    document.querySelector(root).addEventListener('keydown', (event) => {
+      const focusable = [...document.querySelectorAll('.outline-item.focusable')];
+      const currentFocusIndex = focusable.indexOf(event.target);
+
+      switch (event.keyCode) {  // eslint-disable-line default-case
+      case constants.keyCodes.down:
+        event.preventDefault();
+        focusable[Math.min(currentFocusIndex + 1, focusable.length - 1)].focus();
+        break;
+      case constants.keyCodes.up:
+        event.preventDefault();
+        focusable[Math.max(currentFocusIndex - 1, 0)].focus();
+        break;
+      }
+    });
+
+    document.querySelectorAll('a:not([href^="#"])').addEventListener('click', (event) => {
+        Logger.log(
+            'edx.ui.lms.link_clicked',
+            {
+                current_url: window.location.href,
+                target_url: event.currentTarget.href
+            }
+        );
+    });
+  }
+}
diff --git a/openedx/features/course_experience/static/course_experience/js/course_outline_factory.js b/openedx/features/course_experience/static/course_experience/js/course_outline_factory.js
deleted file mode 100644
index f2bbcb11ee..0000000000
--- a/openedx/features/course_experience/static/course_experience/js/course_outline_factory.js
+++ /dev/null
@@ -1,40 +0,0 @@
-(function(define) {
-    'use strict';
-
-    define([
-        'jquery',
-        'logger',
-        'edx-ui-toolkit/js/utils/constants'
-    ],
-        function($, Logger, constants) {
-            return function(root) {
-                // In the future this factory could instantiate a Backbone view or React component that handles events
-                $(root).keydown(function(event) {
-                    var $focusable = $('.outline-item.focusable'),
-                        currentFocusIndex = $.inArray(event.target, $focusable);
-
-                    switch (event.keyCode) {  // eslint-disable-line default-case
-                    case constants.keyCodes.down:
-                        event.preventDefault();
-                        $focusable.eq(Math.min(currentFocusIndex + 1, $focusable.length - 1)).focus();
-                        break;
-                    case constants.keyCodes.up:
-                        event.preventDefault();
-                        $focusable.eq(Math.max(currentFocusIndex - 1, 0)).focus();
-                        break;
-                    }
-                });
-
-                $('a:not([href^="#"])').click(function(event) {
-                    Logger.log(
-                        'edx.ui.lms.link_clicked',
-                        {
-                            current_url: window.location.href,
-                            target_url: event.currentTarget.href
-                        }
-                    );
-                });
-            };
-        }
-    );
-}).call(this, define || RequireJS.define);
diff --git a/openedx/features/course_experience/templates/course_experience/course-outline-fragment.html b/openedx/features/course_experience/templates/course_experience/course-outline-fragment.html
index aec86ad9c8..21bfa195b8 100644
--- a/openedx/features/course_experience/templates/course_experience/course-outline-fragment.html
+++ b/openedx/features/course_experience/templates/course_experience/course-outline-fragment.html
@@ -12,10 +12,6 @@ from django.utils.translation import ugettext as _
 from openedx.core.djangolib.markup import HTML, Text
 %>
 
-<%static:require_module_async module_name="course_experience/js/course_outline_factory" class_name="CourseOutlineFactory">
-    CourseOutlineFactory('.block-tree');
-</%static:require_module_async>
-
 <main role="main" class="course-outline" id="main" tabindex="-1">
     % if blocks.get('children'):
         <ol class="block-tree" role="tree">
@@ -163,3 +159,7 @@ from openedx.core.djangolib.markup import HTML, Text
 <%static:require_module_async module_name="js/dateutil_factory" class_name="DateUtilFactory">
     DateUtilFactory.transform('.localized-datetime');
 </%static:require_module_async>
+
+<%static:webpack entry="CourseOutline">
+    new CourseOutline('.block-tree');
+</%static:webpack>
diff --git a/package.json b/package.json
index 50e4eac706..0f5fb8b8c7 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,13 @@
     "underscore.string": "~3.3.4"
   },
   "devDependencies": {
+    "babel-core": "^6.23.0",
+    "babel-loader": "^6.4.0",
+    "babel-plugin-react": "^1.0.0",
+    "babel-plugin-transform-object-rest-spread": "^6.23.0",
+    "babel-polyfill": "^6.23.0",
+    "babel-preset-env": "^1.2.1",
+    "babel-preset-react": "^6.23.0",
     "edx-custom-a11y-rules": "0.1.3",
     "eslint-config-edx": "^2.0.0",
     "eslint-config-edx-es5": "^2.0.0",
@@ -38,6 +45,8 @@
     "pa11y-reporter-json-oldnode": "1.0.0",
     "plato": "1.2.2",
     "sinon": "1.17.3 || >1.17.4 <2.0.0",
-    "squirejs": "^0.1.0"
+    "squirejs": "^0.1.0",
+    "webpack": "^2.2.1",
+    "webpack-bundle-tracker": "^0.2.0"
   }
 }
diff --git a/requirements/edx/base.txt b/requirements/edx/base.txt
index 188b95a86e..5c37f6e36d 100644
--- a/requirements/edx/base.txt
+++ b/requirements/edx/base.txt
@@ -115,6 +115,7 @@ xmltodict==0.4.1
 django-ratelimit-backend==1.0
 unicodecsv==0.9.4
 django-require==1.0.11
+django-webpack-loader==0.4.1
 pyuca==1.1
 wrapt==1.10.5
 zendesk==1.1.1
diff --git a/webpack.config.js b/webpack.config.js
new file mode 100644
index 0000000000..9a63338265
--- /dev/null
+++ b/webpack.config.js
@@ -0,0 +1,58 @@
+const path = require('path');
+const webpack = require('webpack');
+const BundleTracker = require('webpack-bundle-tracker');
+
+const isProd = process.env.NODE_ENV === 'production';
+
+const wpconfig = {
+  context: __dirname,
+
+  entry: {
+    CourseOutline: './openedx/features/course_experience/static/course_experience/js/CourseOutline.js',
+  },
+
+  output: {
+      path: path.resolve(__dirname, 'common/static/bundles'),
+      filename: '[name]-[hash].js',
+      libraryTarget: 'window',
+  },
+
+  plugins: [
+    new webpack.NoEmitOnErrorsPlugin(),
+    new webpack.NamedModulesPlugin(),
+    new webpack.DefinePlugin({
+      'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV || 'development'),
+    }),
+    new webpack.LoaderOptionsPlugin({
+      debug: !isProd,
+    }),
+    new BundleTracker({
+      filename: './webpack-stats.json'
+    }),
+  ],
+
+  module: {
+    rules: [
+      {
+        test: /\.js$/,
+        exclude: /node_modules/,
+        use: 'babel-loader',
+      },
+    ],
+  },
+  resolve: {
+    extensions: ['.js', '.json'],
+  }
+};
+
+if (isProd) {
+  wpconfig.plugins = [
+    new webpack.LoaderOptionsPlugin({
+      minimize: true,
+    }),
+    new webpack.optimize.UglifyJsPlugin(),
+    ...wpconfig.plugins,
+  ];
+}
+
+module.exports = wpconfig;