How to assign a value to field within a macro?

I’d like to create a macro to assign a value to a calling tiddler’s field:

\define assignToField(order)

<$action-setfield $tiddler=<<currentTiddler>> $field="order-number" $value=<<order>>/>


I’d like to do this in the flow of the macro itself i.e. NOT by using a button. But I can’t make it work.

Is it possible?


You may know this already, but it is good to make clear for newbies:

A macro is just a declaration of WikiText that will replace every “macro call” reference.

So whatever you need to put in the macro declaration is the exact same thing you would put at the location of, and instead of, the “macro call” reference.

The only possible difference between the “thing” you would put wherever directly or in a macro declaration: the macro declaration let’s you specify “placeholder substitutions” via parameter values, so that the snippet of WikiText will work generically, giving different results depending on context (that context figured out via those parameter values.)

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No, not possible. ActionWidgets can only be triggered by TriggerWidgets:

So actions must be initiated by some form of user interaction.

It is possible, AFAIU, to make e.g field values be set upon page load, i.e without user interaction.

Following on: you can do this with startup actions, assuming that you don’t need the field to reflect changes made since startup. (And if you do, you probably want to tie the $action-setfield to the trigger widget responsible for the change anyway.)

I do have an experimental trigger-widget, which will be activated when a tiddler is rendered. I do not propagate it because it has the potential to brick a wiki if done wrong.

You need a trigger.

What is the event that should cause the value to be assigned to the field?

i.e.: when should the assignment happen?

If it is, I’d be very surprised. Making changes to a tiddler just by opening it seems like tragic design. Wouldn’t it also update the tiddler every time it refreshed? And thus by updating, it would refresh? And thus by refreshing, It would update? etc…

The act of opening and viewing a tiddler seems like a side-effect free action, at least I would think it should be.

To answer your question, I’m not sure what you’re trying to do, but it might work out better for you if you detected changes to $:/HistoryList. It updates with every opened tiddler, and it maintains an order. Or you could take advantage of the tv-story-list variable.

I was referring to what @etardiff followed up with, i.e startup actions. Or can “page load” refer to some other time? Or maybe I’m wrong anyway and you can’t set a field value even at that point? I never used startup actions so I’m not sure.

No no. Not by opening a tiddler. At TiddlyWiki startup.

Well, that’s my understanding of the reply by @twMat .

Oops, did not notice twMat already replied.

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Ooh, you’re right. I misread.

Nope, you’re spot on.

I use startup actions quite heavily, all kinds of action widgets.


I understand what your are after and its seems like a barrier to using tiddlywiki, however there are good reasons why you need a trigger.

However there are a lot of ways to solve things in tiddlywiki and tools to help. For example we can piggyback on existing triggers.

However could you explain when and how you want this field to be set at a practical or logical level without code? Think about what it means to the user, what it means to them?

I am sure we can get the result you want if not by others means.

Macros come into being when they are defined and I am sure you dont want it happening then.

  • you can include a trigger such as a button in a macro but the user needs to click it.

The aim is to facilitate diverse modes of presentation of images and their descriptions in TiddlyWiki.

I have a wiki with lots (hundreds) of image tiddlers (Bobwin.exe) each of which is a component of a narrative theme, each theme is represented by a uuid stored in a field. A narrative tiddler uses a macro to filter component tiddlers thus:

<<narrativeMaker "4a45696f-5fbd-4054-996b-523a0293727c">>

the narrativeMaker macro brings together the components of the theme and formats the visual presentation. There is a small-scale demo of the principles here: TiddlyImage — Beautifully compose & curate visual narratives

Because the uuid is passed as a parameter to the macro I wanted to find a technique to extend the narrativeMaker macro to store the uuid into a field, thereby solving the issue that I have hundreds of existing narratives and I would like to get programmatic access to their uuids. Use logic to check if the field exists, if not then create it.

Once programatic access to the uuids is possible the intention is then to extend the demo Tag Filtering tiddler such that the results are presented not just as a link, but enriched with a gallery of thumbnails for each result. Such as described here: Grid CSS in Tiddlywiki Demystified - #4 by Mohammad . Ideally each thumbnail when hovered upon would pop out with its enlarged image and text description.

Any help or guidance in accomplishing this would be much appreciated.

Have you looked at creating a single button to process all tiddlers and assign the UUID (If that what you want) in a batch. Then set up your new tiddler button to also add the UUID to all future tiddlers created that way?

Good idea, thanks, a single button to process all tiddlers! I’ll do that.

I’d like to create a ‘new narrative’ button that auto-generates a uuid, is there a way to do this?

I am sure but you need to concider your algorithium. You can use a counter as a seed, and a bach number eg on a list widget use the counter=item-no paremater then use the batch number and item-no to apply unique UUID’s

Search tiddlywiki resources for discussions on UID and UUID as its being discussed a few times.

You possibly want a macro you can use both in your button and your batch button.

Have a closer look at the ActionCreateTiddlerWidget and play with all the examples until you understand them.

The first example creates a new (non functional) Homemade Button.

If you click the tag: $:/tags/PageControls pill you’ll see all the functional buttons. You can use them eg: New Tiddler or New Journal to create your own button

have fun!

So I’m reworking the narrativeMaker macro to be called with a field name as parameter but have hit on an issue that I can’t get past; The issue is <fieldvalue> does not appear to be passing its value into the filter. I’ve tried <<fieldvalue>> and fieldvalue, dollar signs and curly brackets in varying quantities, but I’m stumped. If, inplace of <fieldvalue>, I paste a known example uuid value into the filter then everything functions and renders as intended. N.B I get the correct output from <<fieldvalue>> on line 3 so I know the value has been assigned. Anyone know what’s wrong here?

\define narrativeMaker(fieldname)

<$set name=fieldvalue value={{{ [all[current]get[$fieldname$]] }}}>


<!-- Transclude edit & read-only buttons -->>

<!-- Filter by the tiddler's field 'narrative', a uuid, to find the component tiddlers then sort and iterate to display -->

<$list filter="[narrative[<fieldvalue>]!tag[narrative]sort[title]]">
    <!-- Transclude the data via these templates to structure the layout, the absence before '||' in {{ ||Template }} transcludes the current tiddler to the template -->
    {{ ||NarrativeEditTemplate }}
    {{ ||NarrativeImageTemplate }}

<<narrativeMaker test>>