Much POD added
Jess Robinson [Mon, 8 May 2006 22:34:36 +0000 (22:34 +0000)]
lib/DBIx/Class/Versioning.pm

index 864f06f..7e892d7 100644 (file)
@@ -52,32 +52,34 @@ __PACKAGE__->mk_classdata('upgrade_directory');
 sub on_connect
 {
     my ($self) = @_;
-    print "on_connect\n";
+#    print "on_connect\n";
     my $vschema = DBIx::Class::Version->connect(@{$self->storage->connect_info()});
     my $vtable = $vschema->resultset('Table');
     my $pversion;
     if(!$self->exists($vtable))
     {
-        print "deploying.. \n";
+#        print "deploying.. \n";
         $vschema->storage->debug(1);
-        print "Debugging is: ", $vschema->storage->debug, "\n";
+#        print "Debugging is: ", $vschema->storage->debug, "\n";
         $vschema->deploy();
         $pversion = 0;
     }
     else
     {
-        $pversion = $vtable->search(undef, 
-                                    { select => [
-                                             'Version',
-                                             { 'max' => 'Installed' },
-                                             ],
-                                      group_by => [ 'Version' ],
-                                      })->first;
+        my $psearch = $vtable->search(undef, 
+                                      { select => [
+                                                   { 'max' => 'Installed' },
+                                                   ],
+                                            as => ['maxinstall'],
+                                        })->first;
+        $pversion = $vtable->search({ Installed => $psearch->get_column('maxinstall'),
+                                  })->first;
         $pversion = $pversion->Version if($pversion);
     }
+#    warn("Previous version: $pversion\n");
     if($pversion eq $self->VERSION)
     {
-        print "This version is already installed\n";
+        warn "This version is already installed\n";
         return 1;
     }
 
@@ -88,28 +90,36 @@ sub on_connect
 
     if(!$pversion)
     {
-        print "No previous version found, skipping upgrade\n";
+        warn "No previous version found, skipping upgrade\n";
         return 1;
     }
 
+#    $self->create_upgrades($self->upgrade_directoy, $pversion, $self->VERSION);
+
     my $file = $self->ddl_filename($self->upgrade_directory,
                                    $self->storage->sqlt_type,
                                    $self->VERSION
                                    );
+    if(!$file)
+    {
+        # No upgrade path between these two versions
+        return 1;
+    }
+
     $file =~ s/@{[ $self->VERSION ]}/"${pversion}-" . $self->VERSION/e;
     if(!-f $file)
     {
         warn "Upgrade not possible, no upgrade file found ($file)\n";
         return;
     }
-    print "Found Upgrade file: $file\n";
+#    print "Found Upgrade file: $file\n";
     my $fh;
     open $fh, "<$file" or warn("Can't open upgrade file, $file ($!)");
     my @data = split(/;\n/, join('', <$fh>));
     close($fh);
     @data = grep { $_ && $_ !~ /^-- / } @data;
     @data = grep { $_ !~ /^(BEGIN TRANACTION|COMMIT)/m } @data;
-    print "Commands: ", join("\n", @data), "\n";
+#    print "Commands: ", join("\n", @data), "\n";
     $self->_filedata(\@data);
 
     $self->backup();
@@ -139,6 +149,8 @@ sub exists
 sub backup
 {
     my ($self) = @_;
+    ## Make each ::DBI::Foo do this
+#    $self->storage->backup();
 }
 
 sub upgrade
@@ -159,7 +171,7 @@ sub upgrade
 sub run_upgrade
 {
     my ($self, $stm) = @_;
-    print "Reg: $stm\n";
+#    print "Reg: $stm\n";
     my @statements = grep { $_ =~ $stm } @{$self->_filedata};
 #    print "Statements: ", join("\n", @statements), "\n";
     $self->_filedata([ grep { $_ !~ /$stm/i } @{$self->_filedata} ]);
@@ -167,9 +179,92 @@ sub run_upgrade
     for (@statements)
     {
         $self->storage->debugfh->print("$_\n") if $self->storage->debug;
-        print "Running \n>>$_<<\n";
+#        print "Running \n>>$_<<\n";
         $self->storage->dbh->do($_) or warn "SQL was:\n $_";
     }
 
     return 1;
 }
+
+=head1 NAME
+
+DBIx::Class::Versioning - DBIx::Class::Schema plugin for Schema upgrades
+
+=head1 SYNOPSIS
+
+  package Library::Schema;
+  use base qw/DBIx::Class::Schema/;   
+  # load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD
+  __PACKAGE__->load_classes(qw/CD Book DVD/);
+
+  __PACKAGE__->load_components(qw/Versioning/);
+  __PACKAGE__->upgrade_directory('/path/to/upgrades/');
+
+  sub backup
+  {
+    my ($self) = @_;
+    # my special backup process
+  }
+
+  sub upgrade
+  {
+    my ($self) = @_;
+
+    ## overridable sub, per default just runs all the commands.
+
+    $self->run_upgrade(qr/create/i);
+    $self->run_upgrade(qr/alter table .*? add/i);
+    $self->run_upgrade(qr/alter table .*? (?!drop)/i);
+    $self->run_upgrade(qr/alter table .*? drop/i);
+    $self->run_upgrade(qr/drop/i);
+    $self->run_upgrade(qr//i);   
+  }
+
+=head1 DESCRIPTION
+
+This module is a component designed to extend L<DBIx::Class::Schema>
+classes, to enable them to upgrade to newer schema layouts. To use this
+module, you need to have called C<create_ddl_dir> on your Schema to
+create your upgrade files to include with your delivery.
+
+A table called I<SchemaVersions> is created and maintained by the
+module. This contains two fields, 'Version' and 'Installed', which
+contain each VERSION of your Schema, and the date+time it was installed.
+
+If you would like to influence which levels of version change need
+upgrades in your Schema, you can override the method C<ddl_filename>
+in L<DBIx::Class::Schema>. Return a false value if there is no upgrade
+path between the two versions supplied. By default, every change in
+your VERSION is regarded as needing an upgrade.
+
+
+=head1 METHODS
+
+=head2 backup
+
+This is an overwritable method which is called just before the upgrade, to
+allow you to make a backup of the database. Per default this method attempts
+to call C<< $self->storage->backup >>, to run the standard backup on each
+database type. 
+
+=head2 upgrade
+
+This is an overwritable method used to run your upgrade. The freeform method
+allows you to run your upgrade any way you please, you can call C<run_upgrade>
+any number of times to run the actual SQL commands, and in between you can
+sandwich your data upgrading. For example, first run all the B<CREATE>
+commands, then migrate your data from old to new tables/formats, then 
+issue the DROP commands when you are finished.
+
+=head2 run_upgrade
+
+ $self->run_upgrade(qr/create/i);
+
+Runs a set of SQL statements matching a passed in regular expression. The
+idea is that this method can be called any number of times from your
+C<upgrade> method, running whichever commands you specify via the
+regex in the parameter.
+
+=head1 AUTHOR
+
+Jess Robinson <castaway@desert-island.demon.co.uk>