Special Copy of Title to Description Field

[History Buff]

In an effort to take advantage of the tree macro, I want to create a button to copy the Title of a filtered set of tiddlers to the description field in a certain way. For instance, if the title of the tiddler is Atchison, Topeka & Santa Fe Railway, I'd like the description field to look like: Railroad-A-Atc-Atchison, Topeka & Santa Fe Railway.

The copying of the title to the description field with the extra text I think is relatively easy. However, I'm having trouble figuring out how to extract the first character and the first three characters from the title. Any suggestions?

Many thanks in advance!

[Eric Shulman]

On Friday, January 8, 2021 at 4:06:27 PM UTC-8 History Buff wrote:

The copying of the title to the description field with the extra text I think is relatively easy. However, I'm having trouble figuring out how to extract the first character and the first three characters from the title. Any suggestions?

Note: the TWCore "toc" macros use the "caption" field (not "description") to define the text to display for each toc entry.

<$button> set captions

  <$list filter="...">

      <$action-setfield caption={{{ [[Railroad]] [{!!title}split[]first[]] [{!!title}split[]first[3]join[]] [{!!title}] +[join[-]] }}} />

   </$list>

</$button>

Notes:

* The $list filter is whatever you want to use to select your desired "set of tiddlers".

* For each matching tiddler, the caption field value is constructed using 5 filter "runs" within a "filtered transclusion" syntax: {{{ ... }}}

* [[Railroad]] is literal text

* [{!!title}split[]first[]] extracts the first character from the title

* [{!!title}split[]first[3]join[]] extracts the first 3 characters from the title

* [{!!title}] is the full title text

* +[join[-]] combines the previous 4 parts with "-" in between each part

The result is a single text value, e.g., "Railroad-A-Atc-Atchison, Topeka & Santa Fe Railway"

which is then stored in the "caption" field of the current tiddler.

enjoy,

-e

[History Buff]

Thanks Eric. That looks just like what I need. I saw the first operator, but thought it returned the entire title of the first item in the list. Now I know better.

As far as using the description field goes, I have a custom tree macro that uses the description field instead of the caption field. I did that (with help) because I needed to use the caption field separately.

I'll let you know how it goes.

[Eric Shulman]

On Saturday, January 9, 2021 at 1:09:02 PM UTC-8 History Buff wrote:

I saw the first operator, but thought it returned the entire title of the first item in the list.

It *does* return the title of the first item in the list.  However, in this usage, first[] is preceded by split[] with no parameter value, which chops up the initial title text into single character "titles".  Note also that first[...] accepts a parameter for how many items to return.  Thus, {!!title}split[]first[] returns a one-character "title", while {!!title}split[]first[3]join[] returns a 3-character "title".

-e

[History Buff]

Ah, that makes perfect sense. Thanks for explaining. That's one of the problems I have with expanding my knowledge of TW. I find it difficult to look beyond the basic uses of the operators and expand my outlook like this. Thanks so much.