Item14775: Add rev parameter for SUBST/EXTRACT maco

It would be nice in using the SUBST or EXTRACT macros with topic parameter to also be able to reference a different revision than the current one. I'd propose simply to add rev parameter similar to that in VarINCLUDE, VarQUERY, and VarFORMFIELD.

-- LynnwoodBrown - 24 Oct 2018

Out of curiousity, I dove into the code of FilterPlugin and found on line 104 this call: (undef, $text) = Foswiki::Func::readTopic($theWeb, $theTopic);. Digging into /lib/Foswiki/Func.pm, I found the readTopic subroutine actually can take a rev parameter. This made me wonder if this might be pretty simple so I tried the following small change to /lib/Foswiki/Plugins/FilterPlugin/Core.pm:

*** Core.orig   2018-10-24 18:08:30.772896067 -0400
--- Core.pm   2018-10-24 18:11:29.687143106 -0400
***************
*** 87,88 ****
--- 87,89 ----
    my $theReverse = $params->{reverse} || '';
+   my $theRev = $params->{rev} || '';

***************
*** 103,105 ****
      $this->{filteredTopic}{"$theWeb.$theTopic"} = 1;
!     (undef, $text) = Foswiki::Func::readTopic($theWeb, $theTopic);
      $text = '' unless defined $text;
--- 104,106 ----
      $this->{filteredTopic}{"$theWeb.$theTopic"} = 1;
!     (undef, $text) = Foswiki::Func::readTopic($theWeb, $theTopic, $theRev);
      $text = '' unless defined $text;

Lo and behold, it seems to work. I have no idea what other ramifications there might be from my tinkering. Perhaps someone with more understanding could comment.

Maybe I'm getting ahead of myself, but here's the simple change needed in the documentation. Under SUBST macro section, add a second bullet item after topic parameter that says:

• rev="...": revision number of topic to be processed. (Use only digits which follow decimal point.) Defaults to latest version.

-- Main.LynnwoodBrown - 25 Oct 2018 - 02:39

Thanks for spotting the missing feature!

-- MichaelDaum - 25 Oct 2018

Commenting is disabled while not logged in