HTML::Widget::Constraint::CallbackOnce - CallbackOnce Constraint

       Carl Franks "cfranks@cpan.org"

       A callback constraint which will only be run once for each call of "process" in HTML::Widget.

       This library is free software, you can redistribute it and/or modify it under the same terms as Perl
       itself.

perl v5.36.0                                       2023-08-10             HTML::Widget::C...t::CallbackOnce(3pm)

callbackcb
       Arguments: \&callback

       Requires a subroutine reference used for validation, which will be passed a list of values corresponding
       to the constraint names.

       "cb" is provided as an alias to "callback".

   process
       Overrides "process" in HTML::Widget::Constraint to ensure "validate" is only called once for each call of
       "validate".

   render_errors
       Arguments: @names

       A list of element names for which an error should be displayed.

       If this is not set, the default behaviour is for the error to be displayed for all of the Constraint's
       named elements.

   validate
       perform the actual validation.

       HTML::Widget::Constraint::CallbackOnce - CallbackOnce Constraint

           my $c = $widget->constraint( 'CallbackOnce', 'foo', 'bar' )->callback(
             sub {
               my ($foo, $bar) = @_;
               return 1 if $foo == $bar * 2;
           });