improving code highlight for blog

Author: prateekbh

content/blog/wanderlust.md

@@ -3,25 +3,25 @@ title: Wanderlust
 date: 2019-08-27T18:44:24.217Z
 tags: 'travel, philosophy, hobby'
 ---
-Sed ut perspiciatis unde omnis iste natus error sit voluptatem #accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. 
+Sed ut perspiciatis unde omnis iste natus error sit voluptatem #accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo.
 
 ## Heading 1
 
 ![](/assets/brett-jordan-1329359-unsplash.jpg)
 
 ## Heading 2
 
-Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt ut labore et dolore magnam aliquam quaerat voluptatem. 
+Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora incidunt ut labore et dolore magnam aliquam quaerat voluptatem.
 
-```
+```js
 navigator.serviceWorker.register('/sw.js').then(reg => {
   reg.onupdatefound = () => {
     const w = reg.installing;
     w.onstatechange = () => {
       if (w.state === 'installed' && navigator.serviceWorker.controller) {
         // probably best to avoid reloading if someone has clicked
         if (hasInteracted) showUpdateToast();
-        
+
         location.reload();
       }
     };

package.json

@@ -1,7 +1,7 @@
 {
   "private": true,
   "name": "blog",
-  "version": "0.0.0",
+  "version": "0.1.0",
   "license": "MIT",
   "scripts": {
     "start": "per-env",
@@ -27,8 +27,9 @@
     "jest-preset-preact": "^1.0.0",
     "markdown": "^0.5.0",
     "per-env": "^1.0.2",
-    "preact-cli": "^3.0.0-rc.6",
+    "preact-cli": "^3.0.0-rc.7",
     "preact-render-spy": "^1.2.1",
+    "react-syntax-highlighter": "^12.2.1",
     "webpack-bundle-analyzer": "^3.4.1"
   },
   "dependencies": {

src/routes/blog/formatted-code-block.js

@@ -0,0 +1,48 @@
+import { h } from 'preact';
+import { useState } from 'preact/hooks';
+
+import { vs } from 'react-syntax-highlighter/dist/esm/styles/prism';
+
+export function FormattedCodeBlock(props) {
+	const [component, setComponent] = useState(null);
+	if (component) {
+		return component;
+	}
+	throw new Promise(resolve => {
+		let language = null;
+		const highlighter = import('react-syntax-highlighter/dist/esm/prism-light');
+		let languageSyntax;
+		switch (props.class) {
+			case 'lang-js':
+				language = 'javascript';
+				languageSyntax = import('react-syntax-highlighter/dist/esm/languages/prism/javascript');
+				break;
+			case 'lang-html':
+				language = 'html';
+				languageSyntax = import('react-syntax-highlighter/dist/esm/languages/prism/markup');
+				break;
+			case 'lang-css':
+				language = 'css';
+				languageSyntax = import('react-syntax-highlighter/dist/esm/languages/prism/css');
+				break;
+			case 'lang-ts':
+				language = 'typescript';
+				languageSyntax = import('react-syntax-highlighter/dist/esm/languages/prism/typescript');
+				break;
+		}
+		Promise.all([highlighter, languageSyntax]).then(values => {
+			const [SyntaxHighlighter, languageHighlighter] = values.map(m => m ? m.default: null);
+			getFormattedCodeBlock(SyntaxHighlighter, languageHighlighter, language, setComponent, resolve, props);
+		});
+	});
+}
+
+function getFormattedCodeBlock(SyntaxHighlighter, languageHighlighter, language, setState, resolve, props) {
+	language && SyntaxHighlighter.registerLanguage(language, languageHighlighter);
+	setState(
+		<SyntaxHighlighter language={language} style={vs}>
+			{props.children}
+		</SyntaxHighlighter>
+	);
+	resolve();
+}

src/routes/blog/index.js

@@ -1,6 +1,9 @@
 import { h } from 'preact';
+import { Suspense } from 'preact/compat';
 import { usePrerenderData } from '@preact/prerender-data-provider';
 import Markdown from 'markdown-to-jsx';
+import { FormattedCodeBlock } from './formatted-code-block';
+
 import style from './style';
 
 const blogs = (props) => {
@@ -12,6 +15,18 @@ const blogs = (props) => {
 	);
 };
 
+function CodeBlock(props) {
+	const fallback = <pre><code>{props.children}</code></pre>;
+	if (typeof window === 'undefined') {
+		return (fallback);
+	}
+	return (
+		<Suspense fallback={fallback}>
+			<FormattedCodeBlock {...props} />
+		</Suspense>
+	);
+}
+
 function getBlogBody(data, isLoading) {
 	if (isLoading) {
 		return (
@@ -35,7 +50,14 @@ function getBlogBody(data, isLoading) {
 				{ details.subtitle && <caption class={style.blogsubtitle}>{details.subtitle}</caption> }
 				{ details.cover && <div class={style.blogcover} style={`background-image:url(${details.cover})`} /> }
 				<div class={style.blogbody}>
-					<Markdown>{ content }</Markdown>
+					<Markdown options={{
+						overrides: {
+							code: {
+								component: CodeBlock
+							}
+						}
+					}}
+					>{ content }</Markdown>
 				</div>
 			</div>
 		);

src/routes/blog/style.css

@@ -20,13 +20,46 @@
   max-width: 100%;
 }
 
+.blogbody a {
+  color: #000;
+  text-decoration: underline;
+}
+
 .blogbody code {
+  display: block;
   max-width: 100%;
+  color: rgb(57, 58, 52);
+  font-family: Consolas, "Bitstream Vera Sans Mono", "Courier New", Courier, monospace;
+  direction: ltr;
+  text-align: left;
+  white-space: pre;
+  word-spacing: normal;
+  word-break: normal;
+  font-size: 0.95em;
+  line-height: 1.2em;
+  tab-size: 4;
+  hyphens: none;
 }
 
-.blogbody pre {
+.blogbody pre pre {
   max-width: 100%;
   overflow: scroll;
+  color: rgb(57, 58, 52);
+  font-family: Consolas, "Bitstream Vera Sans Mono", "Courier New", Courier;
+  direction: ltr;
+  text-align: left;
+  white-space: pre;
+  word-spacing: normal;
+  word-break: normal;
+  font-size: 0.95em;
+  line-height: 1.2em;
+  tab-size: 4;
+  hyphens: none;
+  padding: 1em;
+  margin: 0.5em 0px;
+  overflow: auto;
+  border: 1px solid rgb(221, 221, 221);
+  background-color: white;
 }
 
 .blogsubtitle {

src/static/admin.html

@@ -9,5 +9,32 @@
 <body>
   <!-- Include the script that builds the page and powers Netlify CMS -->
   <script src="https://unpkg.com/netlify-cms@^2.0.0/dist/netlify-cms.js"></script>
+  <script src="//cdn.jsdelivr.net/gh/highlightjs/cdn-release@9.17.1/build/highlight.min.js"></script>
+  <script type="module">
+    import htm from 'https://unpkg.com/htm?module'
+    const html = htm.bind(h);
+    const PostPreview = createClass({
+      render: function() {
+        const {entry, widgetFor} = this.props;
+        const image = entry.getIn(['data', 'cover'])
+        let imageMarkup = '';
+        if (image) {
+          imageMarkup = html`<div><img src='${image.toString()}'/></div>`;
+        }
+        return (
+          html`
+            <div>
+              <h1 className='blogTitle'>${entry.getIn(['data', 'title'])}</h1>
+              <caption className='blogSubTitle'>${entry.getIn(['data', 'subtitle'])}</caption>
+              ${imageMarkup}
+              <div className='text'>${widgetFor('body')}</div>
+            </div>
+          `
+        );
+      }
+    });
+    CMS.registerPreviewStyle("/preview.css");
+    CMS.registerPreviewTemplate("pages", PostPreview);
+  </script>
 </body>
-</html>
+</html>

src/static/config.yml

@@ -12,7 +12,8 @@ collections:
     fields:
       - { label: "Title", name: "title", widget: "string"}
       - { label: "Publish Date", name: "date", widget: "datetime" }
-      - { label: "Subtitle", name: "subtitle", widget: "string"}
-      - { label: "Cover", name: "cover", widget: "image"}
+      - { label: "Subtitle", name: "subtitle", widget: "string", required: false}
+      - { label: "Cover", name: "cover", widget: "image", required: false}
       - { label: "Tags", name: "tags", widget: "string" }
       - { label: "Body", name: "body", widget: "markdown"}
+

src/static/preview.css

@@ -0,0 +1,31 @@
+html {
+  font-family: Helvetica Neue,arial,sans-serif;
+  color: #333;
+  max-width: 728px;
+  width: 100%;
+  margin: 0 auto 10em;
+  line-height: 1.6rem;
+}
+
+img {
+  max-width: 100%;
+}
+
+a {
+  color: #000;
+}
+
+.blogTitle {
+  font-size: 2.2rem;
+  font-weight: 400;
+  margin-bottom: 8px;
+  line-height: 1;
+}
+
+.blogSubTitle{
+  color: #aaa;
+  display: block;
+  text-align: left;
+  font-size: 1.2rem;
+  margin-bottom: 2rem;
+}