NAME

       SQL::Translator::Role::ListAttr - context-sensitive list attributes

SYNOPSIS

           package Foo;
               use Moo;
               use SQL::Translator::Role::ListAttr;

               with ListAttr foo => ( uniq => 1, append => 1 );

DESCRIPTION

       This package provides a variable Moo::Role for context-sensitive list attributes.

FUNCTIONS

   ListAttr $name => %parameters;
       Returns a Moo::Role providing an arrayref attribute named $name, and wrapping the accessor
       to provide context-sensitivity both for setting and getting.  If no "builder" or "default"
       is provided, the default value is the empty list.

       On setting, the arguments are parsed using "parse_list_arg" in SQL::Translator::Utils, and
       the accessor will return an array reference or a list, depending on context.

       Parameters

       append
           If true, the setter will append arguments to the existing ones, rather than replacing
           them.

       uniq
           If true, duplicate items will be removed, keeping the first one seen.

       may_throw
           If accessing the attribute might throw an exception (e.g. from a "builder" or "isa"
           check), this should be set to make the accessor store the exception using
           SQL::Translator::Role::Error and return undef.

       undef_if_empty
           If true, and the list is empty, the accessor will return "undef" instead of a
           reference to an empty in scalar context.

       Unknown parameters are passed through to the has call for the attribute.

SEE ALSO

       SQL::Translator::Utils
       SQL::Translator::Role::Error