Embed modal (#4748)

* Embed modal

* Proxy OEmbed requests from web UI

app/javascript/mastodon/features/ui/components/embed_modal.js

@@ -0,0 +1,84 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+import { FormattedMessage, injectIntl } from 'react-intl';
+import axios from 'axios';
+
+@injectIntl
+export default class EmbedModal extends ImmutablePureComponent {
+
+  static propTypes = {
+    url: PropTypes.string.isRequired,
+    onClose: PropTypes.func.isRequired,
+    intl: PropTypes.object.isRequired,
+  }
+
+  state = {
+    loading: false,
+    oembed: null,
+  };
+
+  componentDidMount () {
+    const { url } = this.props;
+
+    this.setState({ loading: true });
+
+    axios.post('/api/web/embed', { url }).then(res => {
+      this.setState({ loading: false, oembed: res.data });
+
+      const iframeDocument = this.iframe.contentWindow.document;
+
+      iframeDocument.open();
+      iframeDocument.write(res.data.html);
+      iframeDocument.close();
+
+      iframeDocument.body.style.margin = 0;
+      this.iframe.height = iframeDocument.body.scrollHeight + 'px';
+    });
+  }
+
+  setIframeRef = c =>  {
+    this.iframe = c;
+  }
+
+  handleTextareaClick = (e) => {
+    e.target.select();
+  }
+
+  render () {
+    const { oembed } = this.state;
+
+    return (
+      <div className='modal-root__modal embed-modal'>
+        <h4><FormattedMessage id='status.embed' defaultMessage='Embed' /></h4>
+
+        <div className='embed-modal__container'>
+          <p className='hint'>
+            <FormattedMessage id='embed.instructions' defaultMessage='Embed this status on your website by copying the code below.' />
+          </p>
+
+          <input
+            type='text'
+            className='embed-modal__html'
+            readOnly
+            value={oembed && oembed.html || ''}
+            onClick={this.handleTextareaClick}
+          />
+
+          <p className='hint'>
+            <FormattedMessage id='embed.preview' defaultMessage='Here is what it will look like:' />
+          </p>
+
+          <iframe
+            className='embed-modal__iframe'
+            scrolling='no'
+            frameBorder='0'
+            ref={this.setIframeRef}
+            title='preview'
+          />
+        </div>
+      </div>
+    );
+  }
+
+}

app/javascript/mastodon/features/ui/components/modal_root.js

@@ -13,6 +13,7 @@ import {
   BoostModal,
   ConfirmationModal,
   ReportModal,
+  EmbedModal,
 } from '../../../features/ui/util/async-components';
 
 const MODAL_COMPONENTS = {
@@ -23,6 +24,7 @@ const MODAL_COMPONENTS = {
   'CONFIRM': ConfirmationModal,
   'REPORT': ReportModal,
   'ACTIONS': () => Promise.resolve({ default: ActionsModal }),
+  'EMBED': EmbedModal,
 };
 
 export default class ModalRoot extends React.PureComponent {