From: Peter Rabbitson <ribasushi@cpan.org>
Date: Fri, 13 Sep 2013 12:52:41 +0000 (+0200)
Subject: Consolidate single-pk checks from relationship inferrence codepaths
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=0b0743afcb6904727aa51cc39fabeea190f5dac6;p=dbsrgits%2FDBIx-Class-Historic.git

Consolidate single-pk checks from relationship inferrence codepaths
---

diff --git a/lib/DBIx/Class/Relationship/BelongsTo.pm b/lib/DBIx/Class/Relationship/BelongsTo.pm
index 9db06fe..cbc4484 100644
--- a/lib/DBIx/Class/Relationship/BelongsTo.pm
+++ b/lib/DBIx/Class/Relationship/BelongsTo.pm
@@ -26,24 +26,24 @@ sub belongs_to {
   # no join condition or just a column name
   if (!ref $cond) {
     $class->ensure_class_loaded($f_class);
-    my %f_primaries = map { $_ => 1 } try { $f_class->result_source_instance->_pri_cols_or_die }
-      catch {
-        $class->throw_exception( "Can't infer join condition for '$rel' on ${class}: $_");
-      };
 
-    my ($pri, $too_many) = keys %f_primaries;
-    $class->throw_exception(
-      "Can't infer join condition for '$rel' on ${class}: "
-    . "${f_class} has multiple primary keys"
-    ) if $too_many;
+    my $pri = $f_class->result_source_instance->_single_pri_col_or_die;
+
+    my ($f_key, $guess);
+    if (defined $cond and length $cond) {
+      $f_key = $cond;
+      $guess = "caller specified foreign key '$f_key'";
+    }
+    else {
+      $f_key = $rel;
+      $guess = "using given relationship name '$rel' as foreign key column name";
+    }
 
-    my $fk = defined $cond ? $cond : $rel;
     $class->throw_exception(
-      "Can't infer join condition for '$rel' on ${class}: "
-    . "'$fk' is not a column of $class"
-    ) unless $class->has_column($fk);
+      "No such column '$f_key' declared yet on ${class} ($guess)"
+    )  unless $class->has_column($f_key);
 
-    $cond = { "foreign.${pri}" => "self.${fk}" };
+    $cond = { "foreign.${pri}" => "self.${f_key}" };
 
   }
   # explicit join condition
diff --git a/lib/DBIx/Class/Relationship/HasMany.pm b/lib/DBIx/Class/Relationship/HasMany.pm
index f346997..5707c93 100644
--- a/lib/DBIx/Class/Relationship/HasMany.pm
+++ b/lib/DBIx/Class/Relationship/HasMany.pm
@@ -16,15 +16,8 @@ sub has_many {
 
   unless (ref $cond) {
     $class->ensure_class_loaded($f_class);
-    my ($pri, $too_many) = try { $class->result_source_instance->_pri_cols_or_die }
-      catch {
-        $class->throw_exception("Can't infer join condition for '$rel' on ${class}: $_");
-      };
 
-    $class->throw_exception(
-      "has_many can only infer join for a single primary key; ".
-      "${class} has more"
-    ) if $too_many;
+    my $pri = $class->result_source_instance->_single_pri_col_or_die;
 
     my ($f_key,$guess);
     if (defined $cond && length $cond) {
@@ -33,7 +26,7 @@ sub has_many {
     } else {
       $class =~ /([^\:]+)$/;  # match is safe - $class can't be ''
       $f_key = lc $1; # go ahead and guess; best we can do
-      $guess = "using our class name '$class' as foreign key";
+      $guess = "using our class name '$class' as foreign key source";
     }
 
     my $f_class_loaded = try { $f_class->columns };
diff --git a/lib/DBIx/Class/Relationship/HasOne.pm b/lib/DBIx/Class/Relationship/HasOne.pm
index 1281905..57885b3 100644
--- a/lib/DBIx/Class/Relationship/HasOne.pm
+++ b/lib/DBIx/Class/Relationship/HasOne.pm
@@ -25,28 +25,27 @@ sub _has_one {
   unless (ref $cond) {
     $class->ensure_class_loaded($f_class);
 
-    my $pri = $class->_get_primary_key;
-
-    $class->throw_exception(
-      "might_have/has_one needs a primary key  to infer a join; ".
-      "${class} has none"
-    ) if !defined $pri && (!defined $cond || !length $cond);
+    my $pri = $class->result_source_instance->_single_pri_col_or_die;
 
     my $f_class_loaded = try { $f_class->columns };
-    my ($f_key,$too_many,$guess);
+    my ($f_key,$guess);
     if (defined $cond && length $cond) {
       $f_key = $cond;
       $guess = "caller specified foreign key '$f_key'";
     } elsif ($f_class_loaded && $f_class->has_column($rel)) {
       $f_key = $rel;
-      $guess = "using given relationship '$rel' for foreign key";
-    } else {
-      $f_key = $class->_get_primary_key($f_class);
+      $guess = "using given relationship name '$rel' as foreign key column name";
+    } elsif ($f_class_loaded and my $f_pri = try {
+      $f_class->result_source_instance->_single_pri_col_or_die
+    }) {
+      $f_key = $f_pri;
       $guess = "using primary key of foreign class for foreign key";
     }
+
     $class->throw_exception(
       "No such column '$f_key' on foreign class ${f_class} ($guess)"
     ) if $f_class_loaded && !$f_class->has_column($f_key);
+
     $cond = { "foreign.${f_key}" => "self.${pri}" };
   }
   $class->_validate_has_one_condition($cond);
@@ -63,21 +62,6 @@ sub _has_one {
   1;
 }
 
-sub _get_primary_key {
-  my ( $class, $target_class ) = @_;
-  $target_class ||= $class;
-  my ($pri, $too_many) = try { $target_class->result_source_instance->_pri_cols_or_die }
-    catch {
-      $class->throw_exception("Can't infer join condition on ${target_class}: $_");
-    };
-
-  $class->throw_exception(
-    "might_have/has_one can only infer join for a single primary key; ".
-    "${class} has more"
-  ) if $too_many;
-  return $pri;
-}
-
 sub _validate_has_one_condition {
   my ($class, $cond )  = @_;
 
diff --git a/lib/DBIx/Class/ResultSource.pm b/lib/DBIx/Class/ResultSource.pm
index 6e8adcc..3233e3a 100644
--- a/lib/DBIx/Class/ResultSource.pm
+++ b/lib/DBIx/Class/ResultSource.pm
@@ -638,6 +638,20 @@ sub _pri_cols_or_die {
   return @pcols;
 }
 
+# same as above but mandating single-column PK (used by relationship condition
+# inferrence)
+sub _single_pri_col_or_die {
+  my $self = shift;
+  my ($pri, @too_many) = $self->_pri_cols_or_die;
+
+  $self->throw_exception( sprintf(
+    "Operation requires a single-column primary key declared on '%s'",
+    $self->source_name || $self->result_class || $self->name || 'Unknown source...?',
+  )) if @too_many;
+  return $pri;
+}
+
+
 =head2 sequence
 
 Manually define the correct sequence for your table, to avoid the overhead