How a programmer publish static HTML blog in Emacs

As I said, Nikola is my blog generator which converts my org file into HTML.

But I prefer using Org-mode to do the HTML rendering. Nikola only need handle remaining minor book keeping stuff (creating RSS feed, for example).

It's because I want to minimize the dependency. I may switch to other blog generator in the future. But my web site always has the same look and feel because the HTML is generated by Org-mode.

I learned this trick from Org2blog.

If we only use org-mode to create HTML, then extracting code snippet is really easy. All we need is to use regular expression to extract the content between HTML tag "<pre>".

Actually I don't even bother doing the extraction. I just replace all the "<pre>" tag with my own tag because I assume the HTML produced by org-mode is stable.

Here is the Emacs lisp code I borrowed from Org2blog:

(defun org2nikola-replace-pre (html)
  "Replace pre blocks with sourcecode shortcode blocks.
shamelessly copied from org2blog/wp-replace-pre()"
  (save-excursion
    (let (pos code lang info params header code-start code-end html-attrs pre-class)
      (with-temp-buffer
        (insert html)
        (goto-char (point-min))
        (save-match-data
          (while (re-search-forward "<pre\\(.*?\\)>" nil t 1)

            ;; When the codeblock is a src_block
            (unless
                (save-match-data
                  (setq pre-class (match-string-no-properties 1))
                  (string-match "example" pre-class))
              ;; Replace the <pre...> text
              (setq lang (replace-regexp-in-string ".*src-\\([a-zA-Z0-9]+\\).*" "\\1" pre-class)  )

              (replace-match "")
              (setq code-start (point))

              ;; Go to end of code and remove </pre>
              (re-search-forward "</pre.*?>" nil t 1)
              (replace-match "")
              (setq code-end (point))
              (setq code (buffer-substring-no-properties code-start code-end))

              ;; Delete the code
              (delete-region code-start code-end)
              ;; Stripping out all the code highlighting done by htmlize
              (setq code (replace-regexp-in-string "<.*?>" "" code))
              ;; class linenums will add stripes which will destory the 3rd party skins
              (insert (concat "\n<pre class=\"prettyprint lang-"
                              (org2nikola-fix-unsupported-language lang)
                              "\">\n"
                              code
                              "</pre>\n"))
              )))

        ;; Get the new html!
        (setq html (buffer-substring-no-properties (point-min) (point-max))))
      ))
  html)

The code snippet inside "<pre>" tag could be rendered by 3rd party javascript library google-code-prettify or SyntaxHighlighter.

BTW, the last straw that push me away the Wordpress is its wrapper of SyntaxHighlighter. SyntaxHighlighter is a beautiful and user-friendly library. But the wrapper forces me to tweak the php code in terrible editor from Wordpress.

Emacs creates HTML files and meta files. Things created by Emacs will be copied into Nikola's folder.

Nikola's duty is simple. Basically it only copy my stuff from its input folder to its output folder when I trigger "nikola build" command.

The "nikola build" command will also dump the list of files to be uploaded into stdout.

The build message dumped:

Scanning posts....done!
.  render_archive:output/2014/index.html
.  render_sources:output/posts/jump-to-the-positions-before-and-after-m-x-imenu.wp
.  render_posts:cache/posts/jump-to-the-positions-before-and-after-m-x-imenu.html
.  render_indexes:output/index.html
.  render_indexes:output/index-17.html
.  render_tags:output/categories/en.html
.  render_tags:output/categories/emacs.html
.  render_tags:output/assets/js/tag_cloud_data.json
.  render_tags:output/categories/emacs.xml
.  generate_rss:output/rss.xml
.  render_pages:output/posts/jump-to-the-positions-before-and-after-m-x-imenu.html
.  render_pages:output/posts/why-emacs-is-better-editor-part-two.html
.  render_tags:output/categories/en.xml

Only the files in sub-folder "output" need be uploaded.

It's all done by Emacs Lisp.

The final output contain lines like:

ncftpput -b -u yourname -p yourpassword ftp.yourdomain.net /blog/2014/ /home/yourname/nikola-root/output/2014/index.html

As you can see, each line is a ftp upload command we need execute in shell.

Ncftp is my choice of FTP client. It's solid and efficient.

Its command line tool "ncftpput" has a flag "-b". With the flag ncftpput will start a daemon at background and handles the ftp upload as a batch job submit. It means ftp connection will be reused and the user is not blocked by the upload operation. So the upload operation is extremely fast.

I use Emacs Lisp API `file-truename` to convert all relative path to absolute path to avoid any platform (OSX) issue.

BTW, you can `cat ~/.ncftp/spool/log` to check the FTP upload status.