Updated and fixed mathjax parsing, now using full featured plugin

4 files changed, 123 insertions, 14 deletions

diff --git a/public/js/extra.js b/public/js/extra.js
index 90b9a70c..ce00d0e3 100644
--- a/public/js/extra.js
+++ b/public/js/extra.js
@@ -677,6 +677,7 @@ md.use(window.markdownitMark);
 md.use(window.markdownitIns);
 md.use(window.markdownitSub);
 md.use(window.markdownitSup);
+md.use(window.markdownitMathjax);
 
 md.renderer.rules.image = function (tokens, idx, options, env, self) {
     tokens[idx].attrJoin('class', 'raw');
@@ -768,19 +769,6 @@ var gistPlugin = new Plugin(
         return code;
     }
 );
-//mathjax
-var mathjaxPlugin = new Plugin(
-    // regexp to match
-    /^\$\$\n([\d\D]*?)\n\$\$$|\$([\d\D]*?)\$/,
-
-    // this function will be called when something matches
-    function (match, utils) {
-        if (match.index == 0 && (md.meta.mathjax || typeof md.meta.mathjax == "undefined"))
-            return '<span class="mathjax raw">' + match[0] + '</span>';
-        else
-            return match.input.slice(0, match[0].length);
-    }
-);
 //TOC
 var tocPlugin = new Plugin(
     // regexp to match
@@ -863,7 +851,6 @@ md.use(metaPlugin);
 md.use(youtubePlugin);
 md.use(vimeoPlugin);
 md.use(gistPlugin);
-md.use(mathjaxPlugin);
 md.use(tocPlugin);
 md.use(slidesharePlugin);
 md.use(speakerdeckPlugin);
\ No newline at end of file
diff --git a/public/vendor/markdown-it-mathjax.js b/public/vendor/markdown-it-mathjax.js
new file mode 100644
index 00000000..01c6fa43
--- /dev/null
+++ b/public/vendor/markdown-it-mathjax.js
@@ -0,0 +1,120 @@
+// modified from https://github.com/classeur/markdown-it-mathjax
+
+(function(root, factory) {
+	if (typeof exports === 'object') {
+		module.exports = factory()
+	} else {
+		root.markdownitMathjax = factory()
+	}
+})(this, function() {
+	function math(state, silent) {
+		var startMathPos = state.pos
+		if (state.src.charCodeAt(startMathPos) !== 0x5C /* \ */) {
+			return false
+		}
+		var match = state.src.slice(++startMathPos).match(/^(?:\\\[|\\\(|begin\{([^}]*)\})/)
+		if (!match) {
+			return false
+		}
+		startMathPos += match[0].length
+		var type, endMarker, includeMarkers
+		if (match[0] === '\\[') {
+			type = 'display_math'
+			endMarker = '\\\\]'
+		} else if (match[0] === '\\(') {
+			type = 'inline_math'
+			endMarker = '\\\\)'
+		} else if (match[1]) {
+			type = 'math'
+			endMarker = '\\end{' + match[1] + '}'
+			includeMarkers = true
+		}
+		var endMarkerPos = state.src.indexOf(endMarker, startMathPos)
+		if (endMarkerPos === -1) {
+			return false
+		}
+		var nextPos = endMarkerPos + endMarker.length
+		if (!silent) {
+			var token = state.push(type + '_open', 'span', 1);
+            token.attrs = [ ['class', 'mathjax raw'] ];
+            token = state.push(type, '', 0);
+			token.content = includeMarkers ?
+				state.src.slice(state.pos, nextPos) : state.src.slice(startMathPos, endMarkerPos)
+            token = state.push(type + '_close', 'span', -1);
+		}
+		state.pos = nextPos
+		return true
+	}
+
+	function texMath(state, silent) {
+		var startMathPos = state.pos
+		if (state.src.charCodeAt(startMathPos) !== 0x24 /* $ */) {
+			return false
+		}
+
+		// Parse tex math according to http://pandoc.org/README.html#math
+		var endMarker = '$'
+		var afterStartMarker = state.src.charCodeAt(++startMathPos)
+		if (afterStartMarker === 0x24 /* $ */) {
+			endMarker = '$$'
+			if (state.src.charCodeAt(++startMathPos) === 0x24 /* $ */) {
+				// 3 markers are too much
+				return false
+			}
+		} else {
+			// Skip if opening $ is succeeded by a space character
+			if (afterStartMarker === 0x20 /* space */ || afterStartMarker === 0x09 /* \t */ || afterStartMarker === 0x0a /* \n */) {
+				return false
+			}
+		}
+		var endMarkerPos = state.src.indexOf(endMarker, startMathPos)
+		if (endMarkerPos === -1) {
+			return false
+		}
+		if (state.src.charCodeAt(endMarkerPos - 1) === 0x5C /* \ */) {
+			return false
+		}
+		var nextPos = endMarkerPos + endMarker.length
+		if (endMarker.length === 1) {
+			// Skip if $ is preceded by a space character
+			var beforeEndMarker = state.src.charCodeAt(endMarkerPos - 1)
+			if (beforeEndMarker === 0x20 /* space */ || beforeEndMarker === 0x09 /* \t */ || beforeEndMarker === 0x0a /* \n */) {
+				return false
+			}
+			// Skip if closing $ is succeeded by a digit (eg $5 $10 ...)
+			var suffix = state.src.charCodeAt(nextPos)
+			if (suffix >= 0x30 && suffix < 0x3A) {
+				return false
+			}
+		}
+
+		if (!silent) {
+            var type = endMarker.length === 1 ? 'inline_math' : 'display_math';
+			var token = state.push(type + '_open', 'span', 1)
+            token.attrs = [ ['class', 'mathjax raw'] ]
+            token = state.push(type, '', 0);
+			token.content = state.src.slice(startMathPos, endMarkerPos);
+            token = state.push(type + '_close', 'span', -1);
+		}
+		state.pos = nextPos
+		return true
+	}
+
+	function escapeHtml(html) {
+		return html.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/\u00a0/g, ' ')
+	}
+
+	return function(md) {
+		md.inline.ruler.before('escape', 'math', math)
+		md.inline.ruler.push('texMath', texMath)
+		md.renderer.rules.math = function(tokens, idx) {
+			return escapeHtml(tokens[idx].content)
+		}
+		md.renderer.rules.inline_math = function(tokens, idx) {
+			return '\\(' + escapeHtml(tokens[idx].content) + '\\)'
+		}
+		md.renderer.rules.display_math = function(tokens, idx) {
+			return '\\[' + escapeHtml(tokens[idx].content) + '\\]'
+		}
+	}
+})
diff --git a/public/views/foot.ejs b/public/views/foot.ejs
index a77ef864..20db896c 100644
--- a/public/views/foot.ejs
+++ b/public/views/foot.ejs
@@ -33,6 +33,7 @@
 <script src="<%- url %>/vendor/markdown-it-ins/dist/markdown-it-ins.min.js" defer></script>
 <script src="<%- url %>/vendor/markdown-it-sub/dist/markdown-it-sub.min.js" defer></script>
 <script src="<%- url %>/vendor/markdown-it-sup/dist/markdown-it-sup.min.js" defer></script>
+<script src="<%- url %>/vendor/markdown-it-mathjax.js" defer></script>
 <script src="<%- url %>/vendor/markdown-it-regexp.js" defer></script>
 <script src="<%- url %>/vendor/gist-embed.js" defer></script>
 <script src="<%- url %>/vendor/lz-string/libs/lz-string.min.js" defer></script>
diff --git a/public/views/pretty.ejs b/public/views/pretty.ejs
index b07b94ff..9dd61d7d 100644
--- a/public/views/pretty.ejs
+++ b/public/views/pretty.ejs
@@ -85,6 +85,7 @@
 <script src="<%- url %>/vendor/markdown-it-ins/dist/markdown-it-ins.min.js" defer></script>
 <script src="<%- url %>/vendor/markdown-it-sub/dist/markdown-it-sub.min.js" defer></script>
 <script src="<%- url %>/vendor/markdown-it-sup/dist/markdown-it-sup.min.js" defer></script>
+<script src="<%- url %>/vendor/markdown-it-mathjax.js" defer></script>
 <script src="<%- url %>/vendor/markdown-it-regexp.js" defer></script>
 <script src="<%- url %>/vendor/gist-embed.js" defer></script>
 <script src="<%- url %>/vendor/string.min.js" defer></script>