fix(syntax highlighting): Better syntax highlighting

- Update markdown2 to 2.3.5
- Only load syntax files for languages we support
- Enable highlightjs-lang extra to add class to code blocks

frappe/utils/data.py

@@ -943,6 +943,7 @@ def md_to_html(markdown_text):
 		'fenced-code-blocks': None,
 		'tables': None,
 		'header-ids': None,
+		'highlightjs-lang': None,
 		'html-classes': {
 			'table': 'table table-bordered'
 		}

frappe/website/js/syntax_highlight.js

@@ -0,0 +1,18 @@
+const hljs = require('highlight.js/lib/highlight');
+
+hljs.registerLanguage('javascript', require('highlight.js/lib/languages/javascript'));
+hljs.registerLanguage('python', require('highlight.js/lib/languages/python'));
+hljs.registerLanguage('xml', require('highlight.js/lib/languages/xml'));
+hljs.registerLanguage('django', require('highlight.js/lib/languages/django'));
+hljs.registerLanguage('bash', require('highlight.js/lib/languages/bash'));
+hljs.registerLanguage('css', require('highlight.js/lib/languages/css'));
+hljs.registerLanguage('markdown', require('highlight.js/lib/languages/markdown'));
+hljs.registerLanguage('diff', require('highlight.js/lib/languages/diff'));
+hljs.registerLanguage('json', require('highlight.js/lib/languages/json'));
+hljs.registerLanguage('less', require('highlight.js/lib/languages/less'));
+hljs.registerLanguage('nginx', require('highlight.js/lib/languages/nginx'));
+hljs.registerLanguage('scss', require('highlight.js/lib/languages/scss'));
+hljs.registerLanguage('shell', require('highlight.js/lib/languages/shell'));
+hljs.registerLanguage('sql', require('highlight.js/lib/languages/sql'));
+
+module.exports = hljs;

frappe/website/js/website.js

@@ -2,7 +2,7 @@
 // MIT License. See license.txt
 /* eslint-disable no-console */
 
-import hljs from 'highlight.js';
+import hljs from './syntax_highlight';
 
 frappe.provide("website");
 frappe.provide("frappe.awesome_bar_path");
@@ -265,9 +265,7 @@ $.extend(frappe, {
 	},
 
 	highlight_code_blocks: function() {
-		$('pre code').each(function(i, block) {
-			hljs.highlightBlock(block);
-		});
+		hljs.initHighlighting();
 	},
 	bind_filters: function() {
 		// set in select

requirements.txt

@@ -3,7 +3,7 @@ chardet
 dropbox==7.3.1
 gunicorn
 jinja2
-markdown2
+markdown2==2.3.5
 PyMySQL
 maxminddb-geolite2
 python-dateutil