From cb3431bcc4eae2bc5a2851cae10f9dfd8f517c4a Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <m.bunkus@linet-services.de>
Date: Thu, 6 Jun 2013 11:05:15 +0200
Subject: [PATCH] =?utf8?q?L./P.select=5Ftag:=20'default'=20auf=20Liste=20v?=
 =?utf8?q?on=20Rose::DB::Object-Instanzen=20setzen=20k=C3=B6nnen?=
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---
 SL/Presenter/Tag.pm | 52 +++++++++++++++++++++++++++++----------------
 1 file changed, 34 insertions(+), 18 deletions(-)

diff --git a/SL/Presenter/Tag.pm b/SL/Presenter/Tag.pm
index e5690e79d..2bf78ee04 100644
--- a/SL/Presenter/Tag.pm
+++ b/SL/Presenter/Tag.pm
@@ -105,18 +105,7 @@ sub select_tag {
 
   my $with_optgroups  = delete($attributes{with_optgroups});
 
-  my %selected;
-
-  if ( ref($attributes{default}) eq 'ARRAY' ) {
-
-    foreach my $entry (@{$attributes{default}}) {
-      $selected{$entry} = 1;
-    }
-  } elsif ( defined($attributes{default}) ) {
-    $selected{$attributes{default}} = 1;
-  }
-
-  delete($attributes{default});
+  my $default         = delete($attributes{default});
 
   my $normalize_entry = sub {
     my ($type, $entry, $sub, $key) = @_;
@@ -139,6 +128,9 @@ sub select_tag {
     return undef;
   };
 
+  my %selected = map { ( $normalize_entry->('value', $_, $default_sub, $default_key) => 1 ) }
+                     (@{ ref($default) eq 'ARRAY' ? $default : [ $default ]});
+
   my $list_to_code = sub {
     my ($sub_collection) = @_;
 
@@ -157,11 +149,7 @@ sub select_tag {
 
       my $default = $normalize_entry->('default', $entry, $default_sub, $default_key);
 
-      push(@options, [$value, $title, $default]);
-    }
-
-    foreach my $entry (@options) {
-      $entry->[2] = 1 if $selected{$entry->[0]};
+      push(@options, [$value, $title, !!$selected{$value}]);
     }
 
     return join '', map { $self->html_tag('option', $self->escape($_->[1]), value => $_->[0], selected => $_->[2]) } @options;
@@ -218,6 +206,12 @@ Usage from a template:
                                  { direction => 'right', display => 'To the right', selected => 1 } ],
                                value_key => 'direction', title_key => 'display')) %]
 
+  # With Rose::DB::Object instances. For example a group membership
+  # (SL::DB::AuthGroup) for a user (SL::DB::AuthUser) via the user's
+  # "groups" relationship:
+  [% P.select_tag('direction', SELF.all_groups, default=SELF.user.groups,
+                               title_key='name', default_key='id', multiple=1) %]
+
 =head1 DESCRIPTION
 
 A module modeled a bit after Rails' ActionView helpers. Several small
@@ -330,7 +324,29 @@ an empty string.
 
 The option C<default> can be either a scalar or an array reference
 containing the values of the options which should be set to be
-selected.
+selected. How the value from the elements is derived depends on three
+things: the parameters C<default_sub> (unset by default) and
+C<default_key> (default: "selected") as well as the element's type.
+
+=over 4
+
+=item * If C<default_sub> is a code reference then that reference is
+called with the element as its only parameter. The return value is the
+value compared to the value from the elements in C<\@collection>.
+
+=item * If the element in question is a scalar then its value is used.
+
+=item * If the element is a hash then C<default_key> names the index
+into the hash used as the value to select by default.
+
+=item * If the element is a blessed object then C<default_key> names
+the method to call on the object. That method's return value is used
+as the value to select by default.
+
+=back
+
+See the synopsis for an example using C<default> with Rose::DB::Object
+instances.
 
 The tag's C<id> defaults to C<name_to_id($name)>.
 
-- 
2.20.1