How to add a collapsible section in markdown.

markdown-details-collapsible.md

How to add a collapsible section in markdown

1. Example

Click me

Heading

1. Foo
2. Bar
   • Baz
   • Qux

Some Javascript

function logSomething(something) {
  console.log('Something', something);
}

2. Code/Markdown

<details>
  <summary>Click me</summary>
  
  ### Heading
  1. Foo
  2. Bar
     * Baz
     * Qux

  ### Some Javascript
  ```js
  function logSomething(something) {
    console.log('Something', something);
  }
  ```
</details>

3. Tips & Tricks

3.1 Expand by Default

To have a collapsible section expanded by default, simply include the 'open' attribute within the <details> tag:

Hello

World!

<details open>
  <summary>Hello</summary>
  World!
</details>

3.2 Customize Clickable Text

You can modify the appearance of the clickable text by adding styling inside the <summary> tags:

Wow, so fancy

WOW, SO BOLD

<details>
  <summary><i>Wow, so fancy</i></summary>
  <b>WOW, SO BOLD</b>
</details>

3.3 Nested Collapsible Sections

NB: When including headings within collapsible sections, remember to add a new line after the <summary> tag.

Section A

Section A.B

Section A.B.C

Section A.B.C.D

Done!

<details>
<summary>Section A</summary>
<details>
<summary>Section A.B</summary>
<details>
<summary>Section A.B.C</summary>
<details>
<summary>Section A.B.C.D</summary>
  Done!
</details>
</details>
</details>
</details>

Troubleshooting

• If certain markdown or styling, such as # My Title, fails to render in the collapsible section, try adding a line break after the </summary> tag.
• If your section fails to render, it might be malformed. Consider copying the functional examples provided here and building from there!

@moshiurse
about the tag problem
i have tried, if the h2 outside the details is fine. it won't have any new line in the summary. However all the content inside the details will becomes h2

And i think this just the github issue. In long ago, i have tried the same trick in my repo. It work well and dont have any newline, now that repo summary text just move to next line

Hi @moshiurse!

I have the same problem, although it didn't happen a few days ago.

Here you can see something about:

• Error: beatrizsmerino/beatrizsmerino#17
• Solution: beatrizsmerino/beatrizsmerino@ba8980d
• Reason: beatrizsmerino/beatrizsmerino#17 (comment)

I tried everything and in the end I had to use svg images.
In short, the problem is that a few days ago Github didn't treat h1 etc. as block elements, so the arrow and the title were seen side by side.

@Sterh20 the table rendering works without markup <summary>Click me</summary>.

@brunolnetto I was too hasty. Turns out you can make it work with summary section too. You just need to add additional empty line after summary section:

Click me

<details>

  <summary>Click me</summary>

  | Header 1 | Header 2 |
  | -------- | -------- |
  | Row 1    | Row 1    |
  | Row 2    | Row 2    |
  
</details>

Wanted to add that this also works for LaTeX, including double $$ blocks. see example:

---

Rendered Output:

Proof of variance of geometric

Reveal Proof

To compute the variance of $X$, where $X \sim \text{Geom}(p)$, we'll start by finding the second moment. $$E[X^2] = E[X^2 \mid A]P[A] + E[X^2 \mid A^c]P[A^c]$$

Code:

 <details><summary>Reveal Proof</summary>
 To compute the variance of $X$, where $X \sim \text{Geom}(p)$, we'll start by finding the second moment. 
 $$E[X^2] = E[X^2 \mid A]P[A] + E[X^2 \mid A^c]P[A^c]$$
</details>```

Hi! I want to test if I can embed image inside detail.

demo

Content1

Content2

It works! very thanks.

Click

The rest

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

test

Hello everyone here

code:

 <details>
 <summary>test</summary>
 <b>Hello everyone here<b>
 </details>

Using this code in my project README.md on GitHub

### Setup and fine tuning
<details>
<summary><i><h4>1. Main configuration file</h4></i></summary>
For advanced sutup you can edit `config/config.yml` selfexplanatory configuration file.  
This file by default is located in `config` subfolder of program file location.
</details>

---

I get what it should be:

Setup and fine tuning

1. Main configuration file

For advanced sutup you can edit `config/config.yml` selfexplanatory configuration file. This file by default is located in `config` subfolder of program file location.

---

But when I use the same code on GitHub Pages with classic minima skin I get line break between marker and summary tip the same as moshiurse wrote above.

Are any thoughts how to fix this?