markdown-mime

This program sends HTML email using Markdown HTML export.

This approximates a WYSiWYG HTML mail editor from within Emacs, and can be useful for sending tables, fontified source code, and inline images in email.

For example the following message buffer:

To: Eric Schulte <my.self@gmail.com>
Subject: Markdown-mime example email
From: Eric Schulte <my.self@gmail.com>
--text follows this line--
<#secure method=pgpmime mode=sign>
Paragraphs wrapping nicely because nobody expects you to pick your own
line breaks these days.  Also, Markdown export including:

- Fancy *italics* and **bold**,

- lists,

- tables,

    | Heading One   | Heading Two  |
    |---------------|--------------|
    | Content One   | Content Two  |
    | Content Three | Content Four |

- and inline images.

    ![markdown mark](~/Desktop/Markdown-mark.png)

Just call `markdown-mime-htmlize` which you can bind to a key with

```lisp
(add-hook 'message-mode-hook
          (lambda ()
            (local-set-key (kbd "C-c M-o") 'markdown-mime-htmlize)
            (local-set-key (kbd "C-c M-p") 'markdown-mime-preview)
            ;; This next obscure little bit stops
            ;; `electric-indent-mode' from running
            ;; `newline-and-indent' which will strip trailing
            ;; whitespace at the end of a line when RET is
            ;; pressed.  Trailing whitespace is needed in markdown
            ;; syntax to signal a </br>, e.g. after a closing like
            ;; "Thanks,  ".
            (setq electric-indent-inhibit 'electric-layout-mode)))
```

Or (*recommended*) enable list and table editing in your message
buffers with the following (in addition to the above)

```lisp
(add-hook 'message-mode-hook
            (lambda ()
              (when (fboundp 'orgalist-mode) (orgalist-mode 1))
              (when (fboundp 'orgtbl-mode) (orgtbl-mode 1))))
```

Or (*not recommended*) get really really fancy and edit emails in
markdown-mode using mmm-mode with

```lisp
(mmm-add-classes ;; mmm-mode class for markdown keybindings and highlighting
   '((message-minor-markdown
      :submode markdown-mode
      :face mmm-declaration-submode-face
      :front "--text follows this line--"
      :back "^-- ")))
(mmm-add-mode-ext-class 'message-mode nil 'message-minor-markdown)
```

sends an html email rendering as follows:

Setup

(require 'markdown-mime)
;; for gnus – this is set by default
(setq markdown-mime-library 'mml)
;; OR for Wanderlust (WL)
;; (setq markdown-mime-library 'semi)

Usage

`M-x markdown-mime-htmlize`

Run M-x markdown-mime-htmlize from within a mail composition buffer to export either the entire buffer or just the active region to html, and embed the results into the buffer as a text/html mime section.

Export a portion of an email body composed using mml-mode to html using markdown-mode. If called with an active region only export that region, otherwise export the entire body.

Warning: There has been some concern voiced over the potential complexity of email resulting from calling this function on an active region resulting in multiple =multipart/alternative= sections in the same email. Please see this email thread for a discussion of the potential pitfalls of this approach. Speaking from personal experience this has not been a problem for the author.

You could use markdown-mime-edit-mail-in-org-mode edit mail in a special editor with org-mode.

After markdown-mime-htmlize, you can always undo to restore the original plain text mail.

Tips

Pandoc for highlighted source code and tables

The plain markdown markup engine does not support fontified source code or tables. This fun functionality can be relatively easily added by switching to using pandoc as your markdown to HTML exporter, with premailer used as a post-processing step to inline the CSS generated by pandoc into the generated html so that mail user agents won't strip it out.

The pandoc-email.sh script included in this directory is a simple shell script that calls pandoc and passes the results through premailer.

To enable tables and source code highlighting with pandoc and premailer:

Install pandoc.
Install premailer.
Set the value of markdown-command to point to the pandoc-email.sh script in this directory.
```
(setq markdown-command "/path/to/this/repo/pandoc-email.sh")
```

CSS style customization

Email clients will often strip all global CSS from email messages. In the case of web-based email readers this is essential in order to protect the CSS of the containing web site. To ensure that your CSS styles are rendered correctly they must be included in the actual body of the elements to which they apply.

The exported HTML could be modified in markdown-mime-html-hook. For example, below code renders text between "#" in red color,

(add-hook 'markdown-mime-html-hook
          (lambda ()
            (while (re-search-forward "#\\([^#]*\\)#" nil t)
              (replace-match "<span style`\"color:red\">\\1</span>"))))

eschulte / markdown-mime