Lazy load components (#3879)

* feat: Lazy-load routes

* feat: Lazy-load modals

* feat: Lazy-load columns

* refactor: Simplify Bundle API

* feat: Optimize bundles

* feat: Prevent flashing the waiting state

* feat: Preload commonly used bundles

* feat: Lazy load Compose reducers

* feat: Lazy load Notifications reducer

* refactor: Move all dynamic imports into one file

* fix: Minor bugs

* fix: Manually hydrate the lazy-loaded reducers

* refactor: Move all dynamic imports to async-components

* fix: Loading modal style

* refactor: Avoid converting the raw state for each lazy hydration

* refactor: Remove unused component

* refactor: Maintain modal name

* fix: Add as=script to preload link

* chore: Fix lint error

* fix(components/bundle): Check if timestamp is set when computing elapsed

* fix: Load compose reducers for the onboarding modal

1 files changed, 34 insertions, 17 deletions

diff --git a/app/javascript/mastodon/features/ui/components/modal_root.js b/app/javascript/mastodon/features/ui/components/modal_root.js
index 48b048eb7..085299038 100644
--- a/app/javascript/mastodon/features/ui/components/modal_root.js
+++ b/app/javascript/mastodon/features/ui/components/modal_root.js
@@ -1,13 +1,18 @@
 import React from 'react';
 import PropTypes from 'prop-types';
-import MediaModal from './media_modal';
-import OnboardingModal from './onboarding_modal';
-import VideoModal from './video_modal';
-import BoostModal from './boost_modal';
-import ConfirmationModal from './confirmation_modal';
-import ReportModal from './report_modal';
 import TransitionMotion from 'react-motion/lib/TransitionMotion';
 import spring from 'react-motion/lib/spring';
+import BundleContainer from '../containers/bundle_container';
+import BundleModalError from './bundle_modal_error';
+import ModalLoading from './modal_loading';
+import {
+  MediaModal,
+  OnboardingModal,
+  VideoModal,
+  BoostModal,
+  ConfirmationModal,
+  ReportModal,
+} from '../../../features/ui/util/async-components';
 
 const MODAL_COMPONENTS = {
   'MEDIA': MediaModal,
@@ -49,6 +54,22 @@ export default class ModalRoot extends React.PureComponent {
     return { opacity: spring(0), scale: spring(0.98) };
   }
 
+  renderModal = (SpecificComponent) => {
+    const { props, onClose } = this.props;
+
+    return <SpecificComponent {...props} onClose={onClose} />;
+  }
+
+  renderLoading = () => {
+    return <ModalLoading />;
+  }
+
+  renderError = (props) => {
+    const { onClose } = this.props;
+
+    return <BundleModalError {...props} onClose={onClose} />;
+  }
+
   render () {
     const { type, props, onClose } = this.props;
     const visible = !!type;
@@ -70,18 +91,14 @@ export default class ModalRoot extends React.PureComponent {
       >
         {interpolatedStyles =>
           <div className='modal-root'>
-            {interpolatedStyles.map(({ key, data: { type, props }, style }) => {
-              const SpecificComponent = MODAL_COMPONENTS[type];
-
-              return (
-                <div key={key} style={{ pointerEvents: visible ? 'auto' : 'none' }}>
-                  <div role='presentation' className='modal-root__overlay' style={{ opacity: style.opacity }} onClick={onClose} />
-                  <div className='modal-root__container' style={{ opacity: style.opacity, transform: `translateZ(0px) scale(${style.scale})` }}>
-                    <SpecificComponent {...props} onClose={onClose} />
-                  </div>
+            {interpolatedStyles.map(({ key, data: { type }, style }) => (
+              <div key={key} style={{ pointerEvents: visible ? 'auto' : 'none' }}>
+                <div role='presentation' className='modal-root__overlay' style={{ opacity: style.opacity }} onClick={onClose} />
+                <div className='modal-root__container' style={{ opacity: style.opacity, transform: `translateZ(0px) scale(${style.scale})` }}>
+                  <BundleContainer fetchComponent={MODAL_COMPONENTS[type]} loading={this.renderLoading} error={this.renderError} renderDelay={200}>{this.renderModal}</BundleContainer>
                 </div>
-              );
-            })}
+              </div>
+            ))}
           </div>
         }
       </TransitionMotion>