Generating links depending on field value

[Darek Bobak]

I cannot get simple, as I suppose, result:

There is a field. Let's say, bibtex-doiuri.

If the field has any value, i'd like to get as an output:

[[DOI|content_of_the_field]]

If the field is empty, i'd like to get nothing. An empty string.

The result should appear within the $list widget (if it matters).

Darek.

[Eric Shulman]

On Thursday, September 17, 2020 at 6:28:00 AM UTC-7, Darek Bobak wrote:

There is a field. Let's say, bibtex-doiuri.

If the field has any value, i'd like to get as an output:

[[DOI|content_of_the_field]]

If the field is empty, i'd like to get nothing. An empty string.

The result should appear within the $list widget (if it matters).

First, define a macro that assembles the desired output, like this:

\define MakeDOILink() [[DOI|$(uri)$]]

Next, define a macro that gets a field value and passes it to the MakeDOILink, like this:

\define DOILink() <$list filter="[<currentTiddler>get[bibtex-doiuri]]" variable="uri"><<MakeDOILink>></$list>

If the field "bibtex-doiuri" is empty (or doesn't exist) then the get[...] filter doesn't produce any result, and thus <<MakeDOILink>> is not invoked.

Then, to use it, just write:

<<DOILink>>

enjoy,

-e

[Darek Bobak]

Great, thaks! I didn't come up with an idea to use the $list widget

best

Darek