Hard-replace macros

[andjar]

Based on the discussion on google groups, there seems to be an interest in the feature of having a macro replaced with its output when a tiddler is saved. For example, if you want a timestamp, you could just write <<<now>>> and then the macro is replaced with the actual time when you save the tiddler (or already during edit if possible?). In general, <<<macro>>> would be replaced by the wikified output of <<macro>>. This is similar to template substitution in mediawiki. This way, you are guaranteed that the content will not change if you send the tiddler to another wiki, edit the macro, or want a simple way fine-tune the macro output without editing the macro itself

[Jermolene]

I've been following those discussions with interest. I like the idea of being able to perform custom transformations on the text of a tiddler when saving it.

We could go further by also allowing for transformations that are applied when a text area is initialised with the text of a tiddler. That should make it possible to build an editor that edits a tiddler and its fields in a single textarea using ".tid" file format.

If possible, the transformations should be one-to-many, so that the transformations applied to a single text area can generate multiple tiddlers. That would make it possible to present a bunch of tiddler values in a single textarea for ease of editing, just like a data tiddler.

[saqimtiaz]

We could go further by also allowing for transformations that are applied when a text area is initialised with the text of a tiddler.

This would allow use cases like being able to transform a TiddlyWiki format date string (as used in the created/modified fields) into a format appropriate for <input type="date">

It would also be interesting to allow actions to be specified to be invoked before saving a tiddler, without having to edit shadow tiddlers.