At the moment it is really hard for plugins to know where their handlers were invoked from. One of the problems this causes is that a plugin which generates active content (e.g. forms and javascript) doesn't know if the context is a view, a preview, an rdiff or a changes. So the plugins have to use rather dodgy methods of trying to determine their context. For example, CommentPlugin does this:

       my $scriptname = $ENV{'SCRIPT_NAME'} || '';
       my $previewing = ($scriptname =~ /\/(preview|gnusave|rdiff)/);

It would be much better to have a reliable way for a plugin to determine what context it is in. Here are some of the context identifiers I would find useful in my various plugins:

Context	Comments
active	Plain view requiring active content e.g. view, edit
passive	Plain view requiring disabled content e.g. preview, rdiff. Mutually exclusive with active.
text	Rendering main text body
include	Rendering included text
formfield=	Rendering form field data
template	Rendering template text

(Please add to/modify the table above as appropriate)

The specific proposal is to add:

StaticMethod TWiki::Func::getContext() -> $attrs

• $attrs - comma-separated list of attributes of the current context.

Determine the context of this handler call. For example, to determine if a form input field should be disabled in the current rendering context, you might write:

my $context = TWiki::Func::getContext();
if( $context =~ /\bpassive\b/ ) {
    $_[0] =~ s/%TAG%/<input disabled="disabled" name="bah" value="BAH" \/>/g;
} elsif( $context =~ /\bactive\b/ ) {
    $_[0] =~ s/%TAG%/<input name="bah" value="BAH" \/>/g;
} else {
    # neither active nor passive, so don't do any changes to the text
}

Contributors: CrawfordCurrie

No comments or support, so I'm moving this off the Dakar list.

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Done in Dakar.