themillhousegroup/md-in-blogger

Embedding Markdown in a Blogger HTML page.

2023 Update

Embedding Markdown (and Mermaid.js diagrams) in a Blogger HTML page (2023 edition)

Rationale:

See my blog post at https://blog.themillhousegroup.com/2023/10/markdown-and-mermaid-on-blogger-in-2023.html

Instructions:

• Open your template by going to ** Theme -> Customize -> Edit HTML**
• Add the following stylesheet at the top, just after the title tag:

    <link href='//cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/default.min.css' rel='stylesheet'/>

• Add the following scripts to the bottom, just before the /html tag:

   <script src='//cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js' type='text/javascript'/>
   <script src='//cdnjs.cloudflare.com/ajax/libs/showdown/2.1.0/showdown.min.js' type='text/javascript'/>
   <script src='https://code.jquery.com/jquery-3.7.1.min.js' type='text/javascript'/>
   <script src='https://cdn.jsdelivr.net/npm/[email protected]/dist/mermaid.min.js' type='text/javascript'/>
   <script src='//themillhousegroup.github.io/md-in-blogger/markdown-highlight-in-blogger.js' type='text/javascript'/>

- Save your template
- Do the same if you're using a custom mobile template
- Now if you want to write your whole blog post in Markdown, add the `markdown-enabled` Label to the post
- If you just want to use Markdown in certain sections, use the `pre class="markdown"` solution as shown below
- If you want to use Mermaid diagrams, use a ` ```mermaid ... ``` ` code fence and away you go!

### Running this locally (for development/debugging)
- Install `serve` (e.g. `brew install serve`)
- `% serve . -l 8080` from the project root
- Select `test.html`

# 2017 Edition below:

This originally was on my blog at https://js-react.blogspot.com/2017/01/using-markdown-in-blogger.html.

[Markdown](http://daringfireball.net/projects/markdown/) has become very popular due to its simplicity and its wide adoption in Github and other developer websites. So when I was looking at Blogger to start a blog, I wanted the same easy syntax. I had expected that Blogger would support Markdown natively. Alas it does not. 

I found [Francis's blog](http://blog.chukhang.com/2011/09/markdown-in-blogger.html) that explained on how to do this on the client side (no server needed!). Unfortunately it was written a few years ago and there was no updated docs on the steps to do it. So I rolled up my sleeves and took the same approach but using the latest versions of CDN hosted [jQuery](http://www.jquery.com), highlightJS (https://highlightjs.org) and [showDown](https://github.com/showdownjs) libraries. 

jQuery had the nice bonus of cleaning up the previous code by abstracting away the DOM manipulation.

**Caveat - your post shows up as Markdown in RSS feeds.**

## Adding markdown to your Blogger

   1. Open your template, by clicking the "Template" menu item. This displays the current template. Click Edit to modify the template. At the top of your template, add the following tags just before the </head> tag.
```html
    <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/default.min.css"/>

2. At the bottom of the template, add the following tags just before the </html> tag.

<script src='//cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js' type='text/javascript'/>
<script src='//cdnjs.cloudflare.com/ajax/libs/showdown/2.1.0/showdown.min.js' type='text/javascript'/>
<script src='https://code.jquery.com/jquery-3.7.1.min.js' type='text/javascript'/>
<script src='https://cdn.jsdelivr.net/npm/[email protected]/dist/mermaid.min.js' type='text/javascript'/>
<script src='//themillhousegroup.github.io/md-in-blogger/markdown-highlight-in-blogger.js' type='text/javascript'/>

3. Save your template. The first three steps need to be done only once. If you have a mobile template, remember to adjust that template as well.

4. Edit your post and switch from compose to HTML mode (buttons above the editor). Try out this sample.

      <pre class="markdown">
      #Woo hoo!
      [Markdown](http://daringfireball.net/projects/markdown/) is cool!
      ```javascript
          // Verify code highlighting
          if (today==rainy) {
            return false;
          }
      ```
      </pre>

4. You can process the entire blog post as Markdown by applying the markdown-enabled Label to the blog post.

5. Any HTML pre tags with the class markdown are converted by showdown. After this any HTML code tags in the generated HTML are highlighted by highlightJS.

6. Any Markdown code blocks annotated with mermaid as the block language will be converted to Mermaid diagrams.

7. Save your post. Preview or Publish the post.

8. Now go and start mastering Markdown at Github

How it works.

1. Finds pre elements marked with class='markdown' with jQuery, or the main blog post div, if it has the markdown-enabled label
2. Any HTML entities such as > get replaced so that they will be rendered properly
3. Showdown converts the markdown text content into html and injects that back into the post before the pre (and hides the pre).
4. Each code section in the converted HTML is color highlighted by HighlightJS.

I have set the showdown convertor to to GitHub flavor markdown. The libraries are hosted by the kind folks at cdnjs. The core javascript is hosted on github-pages