move non-Riot-specific components over from riot-web

src/components/views/elements/SyntaxHighlight.js

@@ -0,0 +1,53 @@
+/*
+Copyright 2017 Michael Telatynski <7t3chguy@gmail.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from 'react';
+import PropTypes from 'prop-types';
+import {highlightBlock} from 'highlight.js';
+
+export default class SyntaxHighlight extends React.Component {
+    static propTypes = {
+        className: PropTypes.string,
+        children: PropTypes.node,
+    };
+
+    constructor(props, context) {
+        super(props, context);
+
+        this._ref = this._ref.bind(this);
+    }
+
+    // componentDidUpdate used here for reusability
+    // componentWillReceiveProps fires too early to call highlightBlock on.
+    componentDidUpdate() {
+        if (this._el) highlightBlock(this._el);
+    }
+
+    // call componentDidUpdate because _ref is fired on initial render
+    // which does not fire componentDidUpdate
+    _ref(el) {
+        this._el = el;
+        this.componentDidUpdate();
+    }
+
+    render() {
+        const { className, children } = this.props;
+
+        return <pre className={`${className} mx_SyntaxHighlight`} ref={this._ref}>
+            <code>{ children }</code>
+        </pre>;
+    }
+}