From: Peter Rabbitson <ribasushi@cpan.org>
Date: Thu, 10 Jan 2013 13:39:08 +0000 (+0100)
Subject: Deprecate emulate_limit() - can not be sanely supported by DQ
X-Git-Tag: v0.08205~27
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits%2FDBIx-Class.git;a=commitdiff_plain;h=67341081b1a57cc8549e51a8fb1b8cd4661543c5

Deprecate emulate_limit() - can not be sanely supported by DQ
---

diff --git a/Changes b/Changes
index 2751605..b187054 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,9 @@
 Revision history for DBIx::Class
 
+    * New Features / Changes
+        - The emulate_limit() arbitrary limit dialect emulation mechanism is
+          now deprecated, and will be removed when DBIx::Class migrates to
+          Data::Query
     * Fixes
         - When performing resultset update/delete only strip condition
           qualifiers - leave the source name alone (RT#80015, RT#78844)
diff --git a/lib/DBIx/Class/SQLMaker.pm b/lib/DBIx/Class/SQLMaker.pm
index 34b9c80..b45fd68 100644
--- a/lib/DBIx/Class/SQLMaker.pm
+++ b/lib/DBIx/Class/SQLMaker.pm
@@ -133,16 +133,25 @@ sub select {
 
     ($sql, @bind) = $self->next::method ($table, $fields, $where);
 
-    my $limiter =
-      $self->can ('emulate_limit')  # also backcompat hook from SQLA::Limit
-        ||
-      do {
-        my $dialect = $self->limit_dialect
-          or $self->throw_exception( "Unable to generate SQL-limit - no limit dialect specified on $self, and no emulate_limit method found" );
-        $self->can ("_$dialect")
-          or $self->throw_exception(__PACKAGE__ . " does not implement the requested dialect '$dialect'");
-      }
-    ;
+    my $limiter;
+
+    if( $limiter = $self->can ('emulate_limit') ) {
+      carp_unique(
+        'Support for the legacy emulate_limit() mechanism inherited from '
+      . 'SQL::Abstract::Limit has been deprecated, and will be removed when '
+      . 'DBIC transitions to Data::Query. If your code uses this type of '
+      . 'limit specification please file an RT and provide the source of '
+      . 'your emulate_limit() implementation, so an acceptable upgrade-path '
+      . 'can be devised'
+      );
+    }
+    else {
+      my $dialect = $self->limit_dialect
+        or $self->throw_exception( "Unable to generate SQL-limit - no limit dialect specified on $self" );
+
+      $limiter = $self->can ("_$dialect")
+        or $self->throw_exception(__PACKAGE__ . " does not implement the requested dialect '$dialect'");
+    }
 
     $sql = $self->$limiter (
       $sql,
diff --git a/t/sqlmaker/limit_dialects/custom.t b/t/sqlmaker/limit_dialects/custom.t
index 650cd99..1bf3e07 100644
--- a/t/sqlmaker/limit_dialects/custom.t
+++ b/t/sqlmaker/limit_dialects/custom.t
@@ -2,6 +2,7 @@ use strict;
 use warnings;
 
 use Test::More;
+use Test::Warn;
 
 use lib qw(t/lib);
 use DBICTest;
@@ -27,7 +28,8 @@ my $s = DBICTest::Schema->connect (DBICTest->_database);
 $s->storage->sql_maker_class ('DBICTest::SQLMaker::CustomDialect');
 
 my $rs = $s->resultset ('CD');
-is_same_sql_bind (
+
+warnings_exist { is_same_sql_bind (
   $rs->search ({}, { rows => 1, offset => 3,columns => [
       { id => 'foo.id' },
       { 'bar.id' => 'bar.id' },
@@ -45,6 +47,9 @@ is_same_sql_bind (
   )',
   [],
   'Rownum subsel aliasing works correctly'
-);
+ )}
+  qr/\Qthe legacy emulate_limit() mechanism inherited from SQL::Abstract::Limit has been deprecated/,
+  'deprecation warning'
+;
 
 done_testing;