Define&use macros in a data tiddler

Is it possible to define and use macros in a data tiddler? If not, what is the best way to have data tiddler like experience with macros (in Javascript)?

A data tiddler is a tiddler for data. Just data.

What does it mean to have a data tiddler-like experience with macros?

So the tiddler can have macros and after them a list of key:value lines that I can lookup.

Nope, data in data tiddler (say tiddler A), and macros in tiddler B for working with data in (and displaying data from) tiddler A.

Or, macros in a dedicated macros tiddler, say tiddler C.

tiddler B having references to macros in tiddler C, for working with data in (and displaying data from) tiddler A.

I’m talking something like the color palette tiddlers

The data for the colors stored in a data tiddler, say tiddler A.

The widgets and the macros in tiddler B. tiddler B is the interface for working with the data in tiddler A.

The only way for data and “interface” to exist in a same tiddler: forget about data tiddler and store the data in fields of tiddler B.

As soon as you setup a tiddler as a data tiddler, that tiddler’s text field becomes dedicated to the job of storing data. There is no mix and match of data and wiki-text/wiki-script/wiki-widgets in the text field.

I think you should be a bit more specific about your usecase. I’m not sure, what you try to achieve.