Convert SyntaxHighlight to TS

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/components/views/elements/SyntaxHighlight.tsx

@@ -0,0 +1,54 @@
+/*
+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 { highlightBlock } from 'highlight.js';
+import { replaceableComponent } from "../../../utils/replaceableComponent";
+
+interface IProps {
+    className?: string;
+    children?: React.ReactNode;
+}
+
+@replaceableComponent("views.elements.SyntaxHighlight")
+export default class SyntaxHighlight extends React.Component<IProps> {
+    private el: HTMLPreElement = null;
+
+    constructor(props: IProps) {
+        super(props);
+    }
+
+    // componentDidUpdate used here for reusability
+    public componentDidUpdate(): void {
+        if (this.el) highlightBlock(this.el);
+    }
+
+    // call componentDidUpdate because _ref is fired on initial render
+    // which does not fire componentDidUpdate
+    private ref = (el: HTMLPreElement): void => {
+        this.el = el;
+        this.componentDidUpdate();
+    };
+
+    public render(): JSX.Element {
+        const { className, children } = this.props;
+
+        return <pre className={`${className} mx_SyntaxHighlight`} ref={this.ref}>
+            <code>{ children }</code>
+        </pre>;
+    }
+}
+