Add neuron query --list-tags

[srid]

A way to retrieve the list of all tags used in a Zettelkasten.

CLI spec: (--list-tags | --tag TAG | --uri)

[srid]

As well as perhaps --uri zquery://tags (so that we can have a zettel show a list of links to tags as well).

[felko]

Since #115, a --tag-tree command might be helpful to allow editors plugins to implement some kind of "tag browsing" feature.

[srid]

Agreed. What would be the zquery URI equivalent? Here's what I think, at the moment:

• zquery://tags -- show a list of tags in the UI, linking to search.html?tag=foo
• zquery://tags?tree -- same, but render as a tree
  • Or, alternatively, zquery://tags?root=/ -- same as before
  • Whereas zquery://tags?root=math would render only the math sub-tree

Then have CLI map to those queries.

[felko]

Do all the queries need to have a corresponding URI? I would prefer zquery://tags to display the tree in all cases, as it is easier to browse.

I like the zquery://tags?root=math. I would also allow globbing like zquery://tags?glob=math/* since it could happen that you want to display the tree only one level deep.

What would the output look like in the HTML? Will the matched tags be displayed in a tree without any zettels inside? If so, then some kind of zquery://outline?root=math might be useful as well. Here is an idea of how that would look like, assuming that the only tags under math are math/algebra and math/calculus:

# math
[.](zquery://search?tag=math)

## algebra
[.](zquery://search?tag=math/algebra)

## calculus
[.](zquery://search?tag=math/calculus)

That allows the creation of "dynamic outlines" which are automatically updated as new zettels are created under the math tag. Anyway, that should be discussed in a separate issue.

[srid]

It is good to have a 1-on-1 map to queries. I think of neuron query --whatever simply as an alias for using the full form neuron query --uri. Plus, it forces us to think how whatever querying we add to the CLI would impact the HTML view.

Alright, let's do tree by default, and go with zquery://tags?filter=math and zquery://tags?filter=math/* ("filter" is more appropriate naming here, and consistent with the tag-based filtering of search?tag=...).

What would the output look like in the HTML?

Tree of links to the tag search page.

Will the matched tags be displayed in a tree without any zettels inside?

Why would we show the zettels? The user is querying for tags only, not the zettels.

Your outline proposal should indeed be discussed in a different issue (and since you are querying for zettels effectively, it should be done in the zettel query search, but perhaps with a groupBy option i.e.: zquery://search?tag=math/**&groupBy=tag).

[srid]

neuron query --uri zquery://tags returns all tags (as tree), but if somebody really wants a list format, open a PR.