Merge pull request #4 from schollz/math

Works

Former-commit-id: 28099fa7cf5384431b7e8e8e90fbad4c0762ef35 [formerly 15072873d3a0ef2d3e6cf14c020676fbe43e7315] [formerly 39d30f3c06cb065d34468730e0b2dbd05dd6d4b5 [formerly 4bd0d8a69a]]
Former-commit-id: e972807a33606a72b481ec943f21030ec0549315 [formerly ed4f2e145591e31f3d4dafe1ceb1b9bb86c543d0]
Former-commit-id: 6dae915a3825988e96563440a0ca2cea3bce75f5

routes.go

@@ -4,6 +4,7 @@ import (
 	"html/template"
 	"io/ioutil"
 	"net/http"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -62,9 +63,16 @@ func renderMarkdown(c *gin.Context, title string) {
 	}
 	unsafe := blackfriday.MarkdownCommon([]byte(p.Text))
 	html := bluemonday.UGCPolicy().SanitizeBytes(unsafe)
+	html2 := string(html)
+
+	r, _ := regexp.Compile("\\$(.*?)\\$")
+	for _, s := range r.FindAllString(html2, -1) {
+		html2 = strings.Replace(html2, s, "<div class='tex' data-expr='"+s[1:len(s)-1]+"'></div>", 1)
+	}
+
 	c.HTML(http.StatusOK, "view.tmpl", gin.H{
 		"Title": title,
-		"Body":  template.HTML(html),
+		"Body":  template.HTML([]byte(html2)),
 	})
 }
 

templates/view.tmpl

@@ -7,7 +7,8 @@
   {{ template "header" }}
 
   <link rel="stylesheet" type="text/css" href="/static/css/view.css">
-
+  <link rel="stylesheet" type="text/css" href="/static/css/katex.min.css">
+<script src="/static/js/katex.min.js"></script>
 
 
 </head>
@@ -42,6 +43,17 @@
   </div>
 
 
+<script>
+$( document ).ready(function() {
+  var tex = document.getElementsByClassName("tex");
+  Array.prototype.forEach.call(tex, function(el) {
+      katex.render(el.getAttribute("data-expr"), el);
+  });
+
+});
+
+
+</script>
 </body>
 
 </html>