HTML5 <details> in GitHub

example.md

Using <details> in GitHub

Suppose you're opening an issue and there's a lot noisey logs that may be useful.

Rather than wrecking readability, wrap it in a <details> tag!

<details>
 <summary>Summary Goes Here</summary>
 ...this is hidden, collapsable content...
</details>

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/details

A collapsible section with markdown

Click to expand!

def func():
    return 'hello, world!'

Nested

root

bin

nest1

a
b
c

nest2

a b c

file1
file2
file3

boot

x y z

dev

p q r

etc

e t c

home

me you everyone

lib

lib er ate

In Jekyll / Github Pages, even with a blank line the text inside "details" is NOT formatted correctly. It works here on Github:

Spoiler:

First line

Second line

But when I put the same thing into a .md file and run Jekyll serve, I get a sad result:

To add to @cdstanford's comment above ... based on my experiments, mixing markdown formatting into details and summary is a mixed bag. And I am specifically talking about what ends up being presented on github pages with markdown: kramdown

1. Expand/Collapse WORKS in general as a standalone, separate from any other markdown in the .md file

   <details> <summary>Spoiler</summary> my extra lines </details>
   

2. Expand/Collapse WORKS when Nesting details inside a markdown bullet:

   * <details> <summary>Spoiler</summary> my extra lines </details>
   

3. Expand/Collapse Does NOT work if details need to be a sub-bullet:

   * <details> <summary>Spoiler</summary>
       * my extra lines</details>
   

4. Formatting Does NOT work if details need to bold or code formatting:

   * <details> <summary>Spoiler</summary> my `extra` **lines** </details>
   

You can also put a <pre> inside the <details>

A collapsible section with markdown

Click to expand!

Heading

1. A numbered
2. list
   • With some
   • Sub bullets

A collapsible section with markdown

Click to expand!

def func():
    return 'hello, world!'

Super nice feature! ... except that the opened <summary> element is too narrow (has no margin) at the bottom, I feel.
I hope some kind of CSS like this is applied to GitHub for better appearance...

details[open] summary {
    margin-bottom: 16px;
}

Super nice feature! ... except that the opened <summary> element is too narrow (has no margin) at the bottom, I feel.
I hope some kind of CSS like this is applied to GitHub for better appearance...

details[open] summary {
    margin-bottom: 16px;
}

I use <br />&nbsp; at the end of my <summary> content to add an extra line of spacing. HTML works inside this tag. Give it a try.

It will be cool to have an attribute to indicate "default opened" but collapsible

It will be cool to have an attribute to indicate "default opened" but collapsible

This already exists:
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/details

Attribute: "open"

i.e.:

<details open>
    <summary>some summary</summary>
    some opened collapsible
</details>

some summary

some opened collapsible

some summary

> some opened collapsible

some summary

some opened collapsible

It would be nice to be able to use details in numbered and bulleted lists

@RomanSoloweow Looks ugly but works

<details>
<summary>some summary</summary>

A list
- Another list item
- <details><summary>some summary</summary>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc est tellus, convallis eget vulputate ut, eleifend vel mauris. Maecenas consequat aliquam tortor quis bibendum</details>
- Another list item

</details>

some summary

A list

• Another list item
• some summary

  Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nunc est tellus, convallis eget vulputate ut, eleifend vel mauris. Maecenas consequat aliquam tortor quis bibendum
• Another list item

I just wish that GitHub markdown made headings collapsible.

I have a problem on my website with this.
Normal text on my website is smaller than the text within the details. So, the text within "details" looks like 2+ pt bigger than the rest of the text on my site.
Does anyone know why? How can I fix this?

test

+ pp[p
- oo[o

Configuration example

{"a": "b"}

Can you use md markup for linking inside the <summary/> tag? It seems to work inside the <details/> tag.

@rubek-joshi It is possible but there is a catch, it can't be markdown formatting because a new line is required for markdown parsers to parse and render them.

So this is possible

Some bold text code.go link

func main() {}

But not with markdown but with HTML tags

<details><summary><s>Some</s> <b>bold</b> <i>text</i> <code>code.go</code> <a href="//example.com">link</a></summary>

    ```go
    func main() {}
    ```
</details>

can use markdown if you don't mind a newline in your summary link

interface{}

i.e.

<details><summary>

can use *markdown* ~if~ you don't mind a `newline` in _your_ summary [link](//example.com) </summary>
    ```go
    interface{}
    ```
</details>

You can go even crazier and have a multiline image, stack trace, etc. in the summary

slim (3.0.7) lib/slim/parser.rb:513:in syntax_error!' slim (3.0.7) lib/slim/parser.rb:259:inunknown_line_indicator'
slim (3.0.7) lib/slim/parser.rb:250:in parse_line_indicators' slim (3.0.7) lib/slim/parser.rb:192:inparse_line'
slim (3.0.7) lib/slim/parser.rb:95:in call' temple (0.7.7) lib/temple/engine.rb:50:inblock in call'
temple (0.7.7) lib/temple/engine.rb:50:in each' temple (0.7.7) lib/temple/engine.rb:50:ininject'
... show more

slim (3.0.7) lib/slim/parser.rb:513:in syntax_error!' slim (3.0.7) lib/slim/parser.rb:259:inunknown_line_indicator'
slim (3.0.7) lib/slim/parser.rb:250:in parse_line_indicators' slim (3.0.7) lib/slim/parser.rb:192:inparse_line'
slim (3.0.7) lib/slim/parser.rb:95:in call' temple (0.7.7) lib/temple/engine.rb:50:inblock in call'
temple (0.7.7) lib/temple/engine.rb:50:in each' temple (0.7.7) lib/temple/engine.rb:50:ininject'
temple (0.7.7) lib/temple/engine.rb:50:in call' temple (0.7.7) lib/temple/mixins/template.rb:10:incompile'
temple (0.7.7) lib/temple/templates/tilt.rb:30:in prepare' tilt (2.0.5) lib/tilt/template.rb:92:ininitialize'
sprockets (3.6.2) lib/sprockets/legacy_tilt_processor.rb:25:in new' sprockets (3.6.2) lib/sprockets/legacy_tilt_processor.rb:25:incall'
sprockets (3.6.2) lib/sprockets/processor_utils.rb:75:in call_processor' sprockets (3.6.2) lib/sprockets/processor_utils.rb:57:inblock in call_processors'
sprockets (3.6.2) lib/sprockets/processor_utils.rb:56:in reverse_each' sprockets (3.6.2) lib/sprockets/processor_utils.rb:56:incall_processors'
sprockets (3.6.2) lib/sprockets/loader.rb:134:in load_from_unloaded' sprockets (3.6.2) lib/sprockets/loader.rb:60:inblock in load'
sprockets (3.6.2) lib/sprockets/loader.rb:317:in fetch_asset_from_dependency_cache' sprockets (3.6.2) lib/sprockets/loader.rb:44:inload'
sprockets (3.6.2) lib/sprockets/cached_environment.rb:20:in block in initialize' sprockets (3.6.2) lib/sprockets/cached_environment.rb:47:inyield'
sprockets (3.6.2) lib/sprockets/cached_environment.rb:47:in load' sprockets (3.6.2) lib/sprockets/bundle.rb:23:inblock in call'
sprockets (3.6.2) lib/sprockets/utils.rb:196:in dfs' sprockets (3.6.2) lib/sprockets/bundle.rb:24:incall'
sprockets (3.6.2) lib/sprockets/processor_utils.rb:75:in call_processor' sprockets (3.6.2) lib/sprockets/processor_utils.rb:57:inblock in call_processors'
sprockets (3.6.2) lib/sprockets/processor_utils.rb:56:in reverse_each' sprockets (3.6.2) lib/sprockets/processor_utils.rb:56:incall_processors'
sprockets (3.6.2) lib/sprockets/loader.rb:134:in load_from_unloaded' sprockets (3.6.2) lib/sprockets/loader.rb:60:inblock in load'
sprockets (3.6.2) lib/sprockets/loader.rb:317:in fetch_asset_from_dependency_cache' sprockets (3.6.2) lib/sprockets/loader.rb:44:inload'
sprockets (3.6.2) lib/sprockets/cached_environment.rb:20:in block in initialize' sprockets (3.6.2) lib/sprockets/cached_environment.rb:47:inyield'
sprockets (3.6.2) lib/sprockets/cached_environment.rb:47:in load' sprockets (3.6.2) lib/sprockets/base.rb:66:infind_asset'

Like this

<details>
<summary>

![hek](https://picsum.photos/40/40)
    ```ruby
    slim (3.0.7) lib/slim/parser.rb:513:in syntax_error!' slim (3.0.7) lib/slim/parser.rb:259:inunknown_line_indicator'
    slim (3.0.7) lib/slim/parser.rb:250:in parse_line_indicators' slim (3.0.7) lib/slim/parser.rb:192:inparse_line'
    slim (3.0.7) lib/slim/parser.rb:95:in call' temple (0.7.7) lib/temple/engine.rb:50:inblock in call'
    temple (0.7.7) lib/temple/engine.rb:50:in each' temple (0.7.7) lib/temple/engine.rb:50:ininject'
    ... show more
    ```
</summary>
...
</details>

Is it possible to include (Python) code inside summary and serve it on a Jekyll site such that it holds onto the same formatting as a chunk of code that's not inside the summary tag?

So far I either get no formatting at all, or when using pre tag inside summary I get some default formatting but not the one of my style.

test

...this is hidden,collapsable content...

@TomasMiskov yes, but I had to do some digging to find what to do. It required a modification to _config.yml:

markdown: CommonMarkGhPages
commonmark:
  options: ["UNSAFE", "SMART", "FOOTNOTES"]
  extensions: ["strikethrough", "autolink", "table", "tagfilter"]

Which is in the docs by github here.

After I pushed up the above, I was able to do this in github.io pages and *.github.com:

Python3.10

Check out this bash syntax highlighted block:

  brew install [email protected]

  <details>
    <summary>Python3.10</summary>

    Below, you can change the first ``` to ```bash for syntax highlighting :)
    Checkout this regular code block:

    ```
    brew install [email protected]
    ```

  </details>

Here's an example of it working in jekyll.

Thanks @jessebot! In the end, I solved it by encapsulating the code in the Jekyll liquid tag like this:

{% highlight python %}

some code

{% endhighlight %}

More info here.

No problem! Also, thanks for the info on the highlight syntax for Jekyll! :)

Were you able to get that to work on github.com as well? I couldn't find a way that didn't show the {% highlight python %} start and end tag in the code block, but I'm relatively new to Jekyll.

Nested details:

• 1 1- Introduction

  • 1.1 Second Level 1

    • 1.1.1 Third 1a
    • 1.1.2 Third 2a
    • 1.1.3 Third 3a
  • 1.2 Second Level 2

    • 1.2.1 Third 1b
    • 1.2.2 Third 2b
    • 1.2.3 Third 3b
  • 1.5 Alone 1
  • 1.6 Alone 2

Code:

  * <details><summary>1 <a href="#cap1"> 1- Introduction</a></summary><ul>
     <li><details><summary> 1.1 <a href="cap1_1"> Second Level 1 </a> </summary> <ul> 
           <li>1.1.1 <a href="cap1_1_1"> Third 1a </a> </li>
           <li>1.1.2 <a href="cap1_1_2"> Third 2a</a> </li>
           <li>1.1.3 <a href="cap1_1_3"> Third 3a</a> </li>
     </ul></details></li> <!-- End 1 -->
     <li><details><summary> 1.2 <a href="cap1_2"> Second Level 2 </a> </summary> <ul> 
           <li>1.2.1 <a href="cap1_2_1"> Third 1b</a> </li>
           <li>1.2.2 <a href="cap1_2_1"> Third 2b</a> </li>
           <li>1.2.3 <a href="cap1_2_1"> Third 3b</a> </li>
     </ul></details></li> <!-- End  2-->
     <li>1.5 <a href="cap1_5"> Alone 1</a> </li>
     <li>1.6 <a href="cap1_6"> Alone 2</a> </li>
   </ul> <!-- End -->
  </details>

Level 1

Level 2

Level 3

Last Level

#include <bits/stdc++.h>
int main() {
    cout << "Hello World";
}

Level 1

Level 2

Level 3

Last Level

#include <bits/stdc++.h>
int main() {
    cout << "Hello World";
}

Level 1

Level 2

Level 3

Last Level

#include <bits/stdc++.h>
int main() {
    cout << "Hello World";
}

Level 1

Level 2

Level 3

Last Level

#include <bits/stdc++.h>
int main() {
    cout << "Hello World";
}

Level 1

Level 2

Level 3

Last Level

#include <bits/stdc++.h>
int main() {
    cout << "Hello World";
}

Does anyone know how to use an image as a summary of details element?

On click of image, I want to expand.

---

foo bar

😩

Summary Goes Here

...this is hidden, collapsable content...