[tw5] How to format a link using tiddler fields in a list widget.

Hi,

I need the community help as I try to format a link to an external (pdf) ressource using tiddler fields. But I cannot achieve it …

When I run the following list of song with a hard coded link to the external resource, it works
<$list filter="[!is[system]tag[song]sort[song_title]]">

  • [ext[As a download pdf (android) |files/test.pdf]]

</$list>

Now when I try to customize the resource link using the tiddler ‘book_fime_name’ fields like that, It does not work …

<$list filter="[!is[system]tag[song]sort[song_title]]">

  • [ext[As a download pdf (android) |files/{{{ [get[book_file_name]] }}}]]

</$list>

Ir returns

  • As a download pdf (android) }}}]]
  • As a download pdf (android) }}}]]
  • As a download pdf (android) }}}]]
    which is obviously not what I’m looking for …

Any expert in the community to help me ?
I will appreciate

Regards