Warn about both UTF8Columns and ForceUTF8 when loaded improperly

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Componentised.pm

diff --git a/lib/DBIx/Class/Componentised.pm b/lib/DBIx/Class/Componentised.pm
index 7cb5d54..10b91e9 100644 (file)
--- a/lib/DBIx/Class/Componentised.pm
+++ b/lib/DBIx/Class/Componentised.pm
@@ -4,10 +4,65 @@ package # hide from PAUSE
 use strict;
 use warnings;
 
-###
-# Keep this class for backwards compatibility
-###
-
 use base 'Class::C3::Componentised';
+use Carp::Clan qw/^DBIx::Class|^Class::C3::Componentised/;
+use mro 'c3';
+
+# this warns of subtle bugs introduced by UTF8Columns hacky handling of store_column
+# if and only if it is placed before something overriding store_column
+sub inject_base {
+  my $class = shift;
+  my ($target, @complist) = @_;
+
+  # we already did load the component
+  my $keep_checking = ! (
+    $target->isa ('DBIx::Class::UTF8Columns')
+      ||
+    $target->isa ('DBIx::Class::ForceUTF8')
+  );
+
+  my (@target_isa, $base_store_column);
+
+  while ($keep_checking && @complist) {
+
+    @target_isa = do { no strict 'refs'; @{"$target\::ISA"} }
+      unless @target_isa;
+
+    my $comp = pop @complist;
+
+    if ($comp->isa ('DBIx::Class::UTF8Columns') || $comp->isa ('DBIx::Class::ForceUTF8') {
+
+      $keep_checking = 0;
+
+      $base_store_column ||=
+        do { require DBIx::Class::Row; DBIx::Class::Row->can ('store_column') };
+
+
+      my @broken;
+      for my $existing_comp (@target_isa) {
+        my $sc = $existing_comp->can ('store_column')
+          or next;
+
+        if ($sc ne $base_store_column) {
+          require B;
+          my $definer = B::svref_2object($sc)->STASH->NAME;
+          push @broken, ($definer eq $existing_comp)
+            ? $existing_comp
+            : "$existing_comp (via $definer)"
+          ;
+        }
+      }
+
+      carp "Incorrect loading order of $comp by $target will affect other components overriding 'store_column' ("
+          . join (', ', @broken)
+          .'). Refer to the documentation of DBIx::Class::UTF8Columns for more info'
+        if @broken;
+    }
+
+    unshift @target_isa, $comp;
+  }
+
+  $class->next::method(@_);
+}
 
 1;