List Widget Filters "Only" operator

[John McDonnell]

Hi all, I'm looking for a way to filter tiddlers in a list that only contain certain tags.

For example, lets say I want to select only tiddlers with Tag1 and Tag2 an no other tags.

Tiddler A Tags: Tag1, Tag2, Tag3

Tiddler B Tags: Tag1, Tag2

Tiddler C Tags: Tag1, Tag2, Tag4

In this limited example I know the filter could be

<<list-links "[tag[Tag1]tag[Tag2]!tag[Tag3]!tag[Tag4]]">>

but if new tags are added I would need to return to manually exclude them with this filter.

Thanks in advance.

[TW Tones]

Hi johnangus...

First you could place  [tag[Tag1]tag[Tag2]!tag[Tag3]!tag[Tag4]] in a tiddler or a macro

eg; $:/config/tag-filter

then reference is as {{$:/config/tag-filter}} as the whole filter or "... {$:/config/tag-filter} ..." within a filter.

Alternatively in a tiddler tagged $:/tags/Macro

\define  tag-filter()  [tag[Tag1]tag[Tag2]!tag[Tag3]!tag[Tag4]]
then reference is as <<tag-filter>> as the whole filter or "... <tag-filter> ..." within a filter.

However to make use of these as parameters to the list-links macro make use of the expanded macrocall widget

<$macrocall $name=list-links filter=<<tag-filter>>/>

or

<$macrocall $name=list-links filter= {$:/config/tag-filter}}  />

Regards

Tones

[PMario]

Hi,

In TW you sometimes need to think different, because filter sets can dynamically change as you found out.

<$set name="condition" value="[tags[]count[]match[1]]">
<$list filter="[tag[a]filter<condition>]"/>
</$set>

In this example, the first filter tag[a] gets all tiddlers that have a tag a.

The second condition is

  - get all tags of that tiddler, 

  - count them and

  - compare to 1" ... So "a" is the only tag because of the initial filter -> \o/

The filter operator applies the condition to the current tiddler and returns its title, if the condition is not empty.

See: https://tiddlywiki.com/#tags%20Operator:%5B%5Btags%20Operator%5D%5D%20%5B%5Bcount%20Operator%5D%5D%20%5B%5Bmatch%20Operator%5D%5D%20%5B%5Bfilter%20Operator%5D%5D%20%5B%5BFilter%20Operators%5D%5D

have fun!

mario

[PMario]

UUPS,

I didn't read your OP good enough, because my solution works for 1 tag only. ... BUT it should contain enough info to figure out, how the filter should look like for your problem;)

-m

[John McDonnell]

Thanks everyone, useful information.

@PMario - I'll take a look at that and:

1) Try and apply the example as written for a single tag to see if I can get it working

2) Try and extend to two tags

It looks like it should be straightforward enough and I'll be able to add a new tool to my belt.

Thanks

John

[PMario]

Hi John,

If you found a solution, it would be nice if you share it.

If it still causes headaches, let us know.

-m

[TW Tones]

A thought! untested.

If you could count the tags and they do not equal two then it can not have two tags.

Then say [tag[Tag1]] +[tag[Tag2]]

[all[current]tags[]count[]match[2]then<currentTiddler>] +[tag[Tag1]] +[tag[Tag2]]

Above untested

The store the above in a tiddler as I suggested in my first reply, then if you added another tag to the set update it only.

Tones

[PMario]

On Tuesday, July 27, 2021 at 2:26:23 PM UTC+2 TW Tones wrote:

[all[current]tags[]count[]match[2]then<currentTiddler>] +[tag[Tag1]] +[tag[Tag2]]

Tony, Your filter uses all tiddlers that have 2 tags and starts to test them.

I did think about this:

<$set name="condition" value="[tag[Tag2]tags[]count[]match[2]]">
  <$list filter="[tag[Tag1]filter<condition>]">

    <<currentTiddler>> <br/>

  </$list>

</$set> 

My filter uses all tiddlers, that have at least Tag1 and tests them if it has Tag2 and only 2 tags. ... Those tiddlers could have 1,2 or more tags. ...

Performace will depend on how the tags are used and how many tiddlers have 2 tags ...

-mario

[TW Tones]

Mario,

Yes, especially with larger tiddlywiki (or even if you think it my be one day), it is best to reduce the set as quickly as possible to a smaller list.

Tones