From 2fc9f06fdf8489a2d5661b794941abb6f863f194 Mon Sep 17 00:00:00 2001
From: Igor Shymko <Igor.Shymko@playtech.com>
Date: Mon, 5 Dec 2016 15:40:52 +0200
Subject: [PATCH] Client javascript support: fixes #18

---
 .gitignore               |  2 ++
 README.md                | 14 ++++++++++++++
 markdown-preview-mode.el | 13 +++++++++++--
 preview.html             |  2 +-
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/.gitignore b/.gitignore
index 9b4291b..2c5047e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,5 @@
 
 # Packaging
 .cask
+
+.markdown-preview.html
diff --git a/README.md b/README.md
index c2dd859..24e84ee 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 Markdown preview mode
 ===========================
 
+
 [![MELPA Stable](http://stable.melpa.org/packages/markdown-preview-mode-badge.svg)](http://stable.melpa.org/#/markdown-preview-mode)
 [![MELPA](http://melpa.org/packages/markdown-preview-mode-badge.svg)](http://melpa.org/#/markdown-preview-mode)
 
@@ -34,6 +35,19 @@ Select your browser from `Value menu`. If it's not there, follow [EmacsWiki: Bro
 In order to change preview styling, run `M-x customize-option` -> `markdown-preview-style`
 and specify a URL to your favourite markdown css file.
 
+## Client javascript
+
+If you'd like to include additional javascript for the preview, add this to your init:
+
+```lisp
+(add-to-list 'markdown-preview-javascript "http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-MML-AM_CHTML")
+```
+or, to make it async:
+
+```lisp
+(add-to-list 'markdown-preview-javascript '("http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-MML-AM_CHTML" . async))
+```
+
 ## Websocket port
 
 Adjustable by `M-x customize-option` -> `markdown-preview-port`.
diff --git a/markdown-preview-mode.el b/markdown-preview-mode.el
index f45af2d..4a27095 100644
--- a/markdown-preview-mode.el
+++ b/markdown-preview-mode.el
@@ -61,6 +61,9 @@
   :group 'markdown-preview
   :type 'string)
 
+(defvar markdown-preview-javascript (list "http://code.jquery.com/jquery-1.11.0.min.js")
+  "List of javascript libs for preview.")
+
 (defvar markdown-preview--websocket-server nil
   "`markdown-preview' Websocket server.")
 
@@ -90,6 +93,13 @@
       (insert-file-contents markdown-preview--preview-template)
       (if (search-forward "${MD_STYLE}" nil t)
 	  (replace-match markdown-preview-style t))
+      (if (search-forward "${MD_JS}" nil t)
+	  (replace-match
+	   (mapconcat (lambda (x)
+			(concat "<script src=\"" (if (consp x) (car x) x) "\"" (if (consp x) (format " %s" (cdr x))) "></script>" ))
+		      markdown-preview-javascript
+		      "\n")
+	   t))
       (if (search-forward "${WS_HOST}" nil t)
 	  (replace-match markdown-preview-host t))
       (if (search-forward "${WS_PORT}" nil t)
@@ -182,8 +192,7 @@
   (markdown-preview--stop-idle-timer)
   (let ((preview-file (concat (file-name-directory (buffer-file-name)) markdown-preview-file-name)))
     (if (file-exists-p preview-file)
-        (delete-file preview-file)))
-  )
+        (delete-file preview-file))))
 
 ;;;###autoload
 (defun markdown-preview-open-browser ()
diff --git a/preview.html b/preview.html
index 78d0166..1521174 100644
--- a/preview.html
+++ b/preview.html
@@ -10,7 +10,7 @@
          line-height: 1.2em;
      }
     </style>
-    <script src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
+    ${MD_JS}
     <script>
      (function($, undefined) {
          var socket = new WebSocket("ws://${WS_HOST}:${WS_PORT}");