Passing procedure parameter into a filter

1

I have been working on this, seemingly, simple issue for a few days now without success. Hopefully someone more experience can shed some light on what I’m doing wrong.

In a post from 2021, @saqimtiaz posted a filter string to check for a field being empty.

I want to turn that specific string into a procedure that I can use to check any string.

<!-- IS EMPTY-->
\procedure TLSisempty(myField)
{{{ [<currentTiddler>has:field<myField>] :filter[{!!$(myField)$}trim[]is[blank]then[bobj]] }}}
\end

This is what I have come up with so far but when invoked on a tiddler, say using <<TLSisempty “text”>>in the viewtemplate, it just shows the title of the current tiddler in that tiddler’s text field whether there is any text in the text field or not.

Have tried various combinations of brackets but all to no avail.

I also assume, the filter as written, will return the string ‘bobj’ but I want it to be a boolean result, so the invoking code would look something like

<%if <<TLSemptystring “text”>> %>
do something
<%endif%>

All assistance appreciated so I can sleep at night :slight_smile:

bobj

2

Code works for me, if I did understand your text right

\function f.TLSisempty(myField)
[<currentTiddler>get<myField>!is[blank]then[no]else[yes]]
\end

Is empty or field does not exist: <<f.TLSisempty aaa>>

<%if [<f.TLSisempty aaa>match[yes]] %>
show something
<%endif%>

image
image1377×371 35.5 KB

3

Thanks @pmario . I see from your reply I am still thinking in conventional programming terms not TW.

One question, is a function the same as a procedure?

[Edit}: Ah, I see,functions appear t be a V5.4.0 thing

bobj

4

Functions are v5.3.0 thing. They are basically {{{ [[filter string comes here]] }}} without converting the result to a link.

So they output text and the first element is used if the filter would produce a list. They are very handy.

5

Thanks @pmario, must keep up to date with changes

bobj