[Idea] Allow [x] Checkbox Syntax for TW Wikitext

[pmario]

another example is a checkbox widget that has [x] syntax

That is something that I have wanted to have for a long time, and would certainly be worth thinking about again.

On the surface it is fairly straightforward: modify the parser to record the source tiddler and offset of every widget. However, one aspect that is tricky is that the parser parses text strings, not tiddlers. By the time the parser is invoked there is no link between the source tiddler and the corresponding widget.

So, I think we might have to introduce a new interface to the parser that accepts a tiddler title rather than a text string, and thus can fill in the link between widgets and the corresponding offset within the source tiddler. We would then have to go through all the invocations of the parser and where necessary refactor them to use the new interface.

Originally posted by @Jermolene in #9112

[sukima]

There are two takes I see here:

1. The text field itself is source of truth

[ ] and [x] presume the text field itself (the WikiText) is the source of truth. Thus the rendered checkbox would need to be readonly otherwise its state would result in mutating the original text field which is not something any widget has done before. I'm not sure if this follows the spirit of how WikiText/Widgets were designed for.

2. Convert to current checkbox widget under the hood

If the source of truth is a separate field or state tiddler then the distinction between [ ] and [x] does not make a lot of sense.

We would need to consider a stateless sigil and also choose a magical field/state tiddler to use since we would loose the ability to define those concepts like we get if we used <$checkbox> instead.

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Since the intent is typically a list of tasks, another option could be to wrap the concept in a widget.

<$tasklist field="tasks">
* task 1
* task 2
* task 3
</$tasklist>

This could scan the resulting DOM and add an <input type="checkbox"> to each <li> and connect them to a field list.

[pmario]

There is an existing plugin: https://tgrosinger.github.io/tw5-checklist/#%24%3A%2Fplugins%2Ftgrosinger%2Ftw5-checklist which imo shows how it can be implemented. Including a pretty UI for an advanced version.

[Jermolene]

Hi @sukima

1. The text field itself is source of truth

[ ] and [x] presume the text field itself (the WikiText) is the source of truth. Thus the rendered checkbox would need to be readonly otherwise its state would result in mutating the original text field which is not something any widget has done before. I'm not sure if this follows the spirit of how WikiText/Widgets were designed for.

I was referring to this approach because it matches user expectations, and improves interoperability with Markdown. It is indeed tricky to retrofit the mutation of the text field into the current parsing architecture, but I think it could be done in a backwards compatible manner with the approach I outlined.