Change 449128 had a related patch set uploaded (by Samwilson; owner: Samwilson):
[mediawiki/extensions/TemplateWizard@master] Add 'content' type for parameters

https://gerrit.wikimedia.org/r/449128

Regarding the booleans, we could probably get rid of the 'unknown' if there's a default value, but in other cases it's conceivable that templates would be making a distinction between a parameter with no value and a parameter that's not present.

Done; see description.

We could also choose to 'autosize' the textareas, so they get bigger the more text is entered (up to a maximum we specify).

Re T198921: All the input fields should have the same width, would we want the boolean field (whatever we end up choosing for it) to also be full width?

As for width of the boolean, won't we need to be concerned about non-English languages fitting on a single line in the available width?

In T200664#4465473, @aezell wrote:

As for width of the boolean, won't we need to be concerned about non-English languages fitting on a single line in the available width?

What we can do (there are other places that do this type of thing) is request, in the qqq (the explanation for translators) to try and use a relatively short word for the translation. We do this a lot for cases like these, where the action is quick and small. It also makes sense when the words are relatively simple boolean ("true / false / none" etc) We also do this a lot for mobile designs, where the space for wording is already limited, so there's precedent.

Usually, the most "dangerously long" language tends to be German, but since the words are short ("ja" / "nicht" / "unbekannt" if my translation is right) I think it should be safe.

Worse case, if we see some language that are too long, we can relatively easily switch this toggle to be one-button-per-line, which would also work.

I think this is still better than having a free-text input that assumes the user knows to put "1", "0" or "".

I think this is safe enough, though, especially for such short action words, and if we emphasize "use short words" in the qqq.json.

@Mooeypoo Thanks for the clarity on that. I'm glad we have some common solutions there.

The screenshots in the ticket look reasonable to me. I'd agree with @Mooeypoo that using words over 1 / 0 / ' would be easier for most users to understand and preferred overall.

I've created T201378, and moved stuff from here to there.

With the boolean 'unknown': could it be said that if there's a default value of 1 or 0 for a boolean parameter, then we could leave out the 'unkown'? It would look nicer in many cases. I know it doesn't quite cover it, because it is technically possible for a template author to make a distinction between empty when defining the default value. For example, a {{pet}} template might have a is_good parameter with a default of 0:

{{#ifeq: {{{is_good|}}} | 1 | Good dog! | {{#if: {{{is_good|cat}}} | Bad dog! | You're a cat. }} }}

If we can in some circumstances do away with the 'unknown', do we want to change to a checkbox for those ones?

Duplicates T144155: Create dedicated input methods for "boolean" transclusion parameters?