Subject: [xml2rfc-dev] RFC 7991 issue #45: Schema Issue, RFC 7991, In Section 2.29, <li>, Unordered lists with arbitrary symbols

From: [email-masked]
Date: Mon, 08 Oct 2018 07:46:29 -0700

This captures an issue noted during implementation, also described in
https://tools.ietf.org/html/draft-levkowetz-xml2rfc-v3-implementation#section-3.1.6.1

Specification: https://tools.ietf.org/html/rfc7991#section-2.29

---
Unordered lists with arbitrary symbols

   When <li> is used with <ul empty="true">, the rendering is under-
   specified (the specification says 'no label will be shown", but doesn't
   say whether list indentation (leading white-space) should be eliminated
   or not.

   If the intention is to make it possible to render unordered lists with
   arbitrary symbols, chosen on a per-list-item basis, the current
   attributes of <li> are insufficient to indent and line-wrap list items
   properly with <ul empty='true'>.

   It is not possible, for instance, to use <ul> lists to generate XML for
   a table of content, since if the width of the bullet (the section
   number, in this case) is unknown, the proper indentation and line
   wrapping cannot be determined.

   Proposal:        Add an explicit "bullet" attribute to support this use
                    case.

   Implementation:  None in the current version of xml2rfc, but internally
                    bullets are taken a configurable bullet list, so
                    accommodating such an attribute would be trivial.
---

Regards,
	Henrik

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This issue is tracked at:
   https://github.com/rfc-format/draft-iab-xml2rfc-v3-bis/issues/45

Discussion should take place on this list.

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From: Julian Reschke <[email-masked]>
Date: Mon, 8 Oct 2018 17:08:29 +0200

>     say whether list indentation (leading white-space) should be eliminated

Well, rendering in general is not well specified. In particular not for 
plain text output. For HTML it mainly depends on the CSS, which is 
essentially configurable and outside the scope of the language definition.

>     properly with <ul empty='true'>.

No, that was not the intent.

>     wrapping cannot be determined.

I understand that you'd like the vocabulary to do extra as intermediate 
format inside your implementation. That's your design choice, but it 
doesn't need to affect the user-visible vocabulary. For instance, you 
can implement whatever you need to augment the XML in a separate XML 
namespace.

>                      accommodating such an attribute would be trivial.

-1, for the above reasons.

That said, I'm not against having unordered lists with custom symbols, 
but the way you arrived at this proposal doesn't work for me.

Best regards, Julian

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From: Henrik Levkowetz <[email-masked]>
Date: Mon, 8 Oct 2018 17:44:00 +0200

Hi Julian,

> essentially configurable and outside the scope of the language definition.

Understood, but it's still a good thing if there's some consistency to this,
so in some cases guidance on indentation might be warranted.

> No, that was not the intent.

Ok.

> can implement whatever you need to augment the XML in a separate XML 

Ok.  There's more to it than this, but that will appear as a separate
issue.

> but the way you arrived at this proposal doesn't work for me.

Understood.  Would you like to make a separate proposal (with a more
generic argument, I assume) for unordered lists with custom symbols?

Best regards,

	Henrik

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From: Julian Reschke <[email-masked]>
Date: Mon, 8 Oct 2018 20:01:52 +0200

On 2018-10-08 17:44, Henrik Levkowetz wrote:
> ... 
> ...

I'd prefer not to, as this really is a presentation issue; and 
restricting the level of control of the presentation IMHO is a good thing.

Best regards, Julian

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From: Paul Hoffman <[email-masked]>
Date: Tue, 9 Oct 2018 15:24:16 +0000

>                    accommodating such an attribute would be trivial.

I am not in favor of this. "The labels on the items will be symbols picked by the formatter" still seems correct.

For the use case given here (the table of contents has a variable width first element), the text in Section 6.6 of RFC 7992 still seems adequate.

--Paul Hoffman

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From: Julian Reschke <[email-masked]>
Date: Tue, 9 Oct 2018 19:22:43 +0200

> For the use case given here (the table of contents has a variable width first element), the text in Section 6.6 of RFC 7992 still seems adequate.

Well, there never was any intent to make the table of contents be 
rendered as unordered list using <ul>. (FWIW, it's an ordered list anyway).

So we really need to discuss the underlying issue (should we able to 
represent the *contents* of the TOC as XML?).

Best regards, Julian