Hello mario, hello everybody!
Mario, thank you very much for your detailed answer. I was able to transfer your solution to my testing wiki and it works principally and I understand the way it works.
Unfortunately my indended field is in date format. The output of the described tiddler-template-solution is as an unformatted string like 20220829. I could not find a way to enter working format parameters in the transclude line in the template. Do you perhaps have an idea how to format the output to a readable date?
But after all this solution does sadly not address my whole problem. With this tabs-template-solution the definded field content of a tiddler is shown in tabs view, but not in the standard tiddler view. I was looking for a solution which shows the field content in both views.
What I found so far is:
1. Manipulating $:/core/ui/ViewTemplate
When I insert a $view field command in the $:/core/ui/ViewTemplate my field content is shown - if existing - at the top of any tiddler in standard view. Date formatting is possible, but I was not able to make this tag-sensitive. It is not seen in tab view. I am aware that manipulating the common ViewTemplate is a quite brutal way.
Part of my $:/core/ui/ViewTemplate:
```
[<currentTiddler>is[shadow]is[tiddler]then[tc-tiddler-overridden-shadow]] [<currentTiddler>is[system]then[tc-tiddler-system]] [{!!class}] [<currentTiddler>tags[]encodeuricomponent[]addprefix[tc-tagged-]] +[join[ ]] }}}>
''Revisionsstand: <$view field="Stand" format="date" template="MMM YYYY"/>''
<hr>
<$list filter="[all[shadows+tiddlers]tag[$:/tags/ViewTemplate]!has[draft.of]]" variable="listItem">
<$transclude tiddler=<<listItem>>/>
```
2. Manipulating $:/core/macros/tabs
I inserted a $view tiddler line in $:/core/macros/tabs and my field content is shown in tabs view. Again, date formatting works but I clould not make it tag-sensitive.
Part of my $:/core/macros/tabs:
```
<$reveal type="match" state=<<tabsState>> text=<<currentTab>> default="$default$" retain="""$retain$""">
<$transclude tiddler="$template$" mode="block">
''Revisionsstand: <$view tiddler=<<currentTab>> field="Stand" format="date" template="MMM YYYY"/>''
<hr>
<$transclude tiddler=<<currentTab>> mode="block"/>
</$transclude>
```
3. CSS
I was trying to enter some content via Tiddlywiki's CSS interface, like so:
```
.tc-tagged-info:before {
content: "TEST";
}
```
This works with text, but entering html via 'content' seems to be not possible by design. Dead end again.
So, a bunch of questions are still open:
A. Is there a more elegant way to set up my plan of date field content beeing displayed in a tagged tiddler in both, the standard and the tab view?
B. If it has to be a deep manipulation, is it possible to manipulate Tiddlywiki on a single point, so that a date field content is displayed in a tagged tiddler in both, the standard and the tab view?
C. If it have to be the both points which I described in 1. and 2., can these be made tag-sensitive?
Thanks for your patience
Greetings
Oliver Hahn