[tw5] Strange List Issue with list-links

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#1

In the attached TiddlyWiki I describe a strange issue with ‘list-links’. I don’t know if this is an error or I just missed something.

(Attachment strange_list_error.html is missing)

#2

Here’s your code that doesn’t work:

\define listtitle() ''Books by $(currentTiddler)$''
\define filter() "[tag[$(currentTiddler)$]tag[Book]]"

<$list filter=<<filter>> variable="_"> <<listtitle> </$list>

<<list-links filter:"[tag[$(currentTiddler)$]tag[Book]]">>

Here’s what’s wrong:

  1. There is a missing > at the end of <<listtitle>. As a result, the macro call isn’t closed until the final >> at the end of the code. All the content between the error and the ending >> are treated as parameters to the macro.

  2. The $(variablename)$ syntax is only parsed when it occurs within a macro. Thus, "[tag[$(currentTiddler)$]tag[Book]" is actually looking for a literal tag value of $(currentTiddler)$.

  3. You don’t need the double-quotes around the content of \define filter() "...".

  4. If there are multiple Book tiddlers for the current Author, your <$list> widget (with the correction for the missing >) would display the <<listtitle>> text multiple times, once for each matching Book tiddler.

  5. You don’t actually need to use $(currentTiddler)$ anywhere in the above code… <<currentTiddler>> (or <currentTiddler> within a filter) is sufficient. In fact, you don’t need to use any macros at all.

Here’s some corrected/simplified code:

<$list filter="[tag<currentTiddler>tag[Book]limit[1]]" variable="_">''Books by <<currentTiddler>>''</$list>

<<list-links filter:"[tag<currentTiddler>tag[Book]]">>

Notes:

  1. The filter for the heading uses limit[1] so that the heading text is only displayed once, regardless of how many matching Book tiddlers are found.

enjoy,
-e

#3

@Eric Shulman

Thank you for enlightening me!

at 1) A case of blindness: I missed the missing > at the end of `<, because the list title was always displayed.

at 2) I defined the macros, because I hope that some day I can use transclusions with parameters and pass in ‘Book’, ‘Article’, ‘Video’, etc. But even then, as your code shows, I probably wouldn’t need them.

at 3) A misunderstanding: These are not double quotes, but two double single quotes to make the list title bold.

at 4) A case of laziness: I only tested for zero and one cases, not for more than one.

at 5) A case of ignorance: I’m not yet familiar with the finer details of the use of angle brackets within text and filters. Thanks for the clarification.

Your corrected /simpilified code works as desired!

Thanks again,
-Reinhard