Parsing issue with nested lists in details block

[paulnicolet]

Hi all 👋,

First, thanks for your work, it's awesome and very useful !

I think I spotted an issue when trying to add "complex" content in a details block, here is a description:

Without details block

I define the following structure:

Without details block
- Parent 1  
    Intro 1  

    - Child 1
    - Child 2
    - Child 3
    - Child 3

    Outro 1

which yields the following HTML:

<p>Without details block</p>
<ul>
    <li>
        <p>Parent 1<br />
            Intro 1 </p>
        <ul>
            <li>Child 1</li>
            <li>Child 2</li>
            <li>Child 3</li>
            <li>Child 3</li>
        </ul>
        <p>Outro 1</p>
    </li>
</ul>

which gives this in the browser:

With details block

Now, when I try to add a details block around in order to make it collapsible:

???+ "With details block"
    - Parent 1  
        Intro 1  

        - Child 1
        - Child 2
        - Child 3
        - Child 3

        Outro 1

yielding this HTML:

<details open="open">
    <summary>With details block</summary>
    <ul>
        <li>
            <p>Parent 1<br />
                Intro 1 </p>
            <ul>
                <li>Child 1<ul>
                        <li>Child 2</li>
                        <li>Child 3</li>
                        <li>Child 3</li>
                    </ul>
                </li>
            </ul>
            <p>Outro 1</p>
        </li>
    </ul>
</details>

(you can already spot the issue here around Child 1), this gives:

The HTML is badly formatted in the children 2, 3, 4 got one extra level of indentation.

---

I tried a lot of whitespace / linebreaks / indentation combination attempting to solve the issue but I could not make it.

Is there any chance that this comes from the extension itself ?

Thanks a lot guys 😊

[facelessuser]

@paulnicolet

Okay, I have reproduced the issue. The problem seems to specifically be with loose lists. the difference is the spacing of the lists

???+ "Details block with tight lists"
    - Parent 1
        - Child 1
        - Child 2

???+ "With details block with loose lists"
    - Parent 1

        - Child 1
        - Child 2

I'm not quite sure why this happens yet, but this problem is prevalent in all constructs that use the same logic. Python Markdown's Admonitions, Pymdownx's Details, and Pymdownx's Tabbed.

The good news is that the way it happens is quite predictable, so hopefully, it will be easy to fix.

@gir-bot remove S: triage
@gir-bot add T: bug

[facelessuser]

Once we fix this in Details and Tabbed, we issue a fix upstream for Python Markdown's Admonitions.

[facelessuser]

I think I have a solution:

import markdown

text = """
???+ "With details block with loose lists"
    - Parent 1

        - Child 1
        - Child 2
"""

print(markdown.markdown(text, extensions=['pymdownx.details']))

Output:

<details open="open"><summary>With details block with loose lists</summary><ul>
<li>
<p>Parent 1</p>
<ul>
<li>Child 1</li>
<li>Child 2</li>
</ul>
</li>
</ul>
</details>

[facelessuser]

Admonition fix is here: Python-Markdown/markdown#1102.

[paulnicolet]

It works like a charm, thanks a lot for your help and reactivity!