move some general comments to a general role, along with the interface, and initial...

[dbsrgits/DBIx-Class-DeploymentHandler.git] / lib / DBIx / Class / DeploymentHandler / HandlesVersioning.pm

diff --git a/lib/DBIx/Class/DeploymentHandler/HandlesVersioning.pm b/lib/DBIx/Class/DeploymentHandler/HandlesVersioning.pm
new file mode 100644 (file)
index 0000000..7b111a2
--- /dev/null
+++ b/lib/DBIx/Class/DeploymentHandler/HandlesVersioning.pm
@@ -0,0 +1,69 @@
+package DBIx::Class::DeploymentHandler::HandlesVersioning;
+use Moose::Role;
+
+requires 'next_version_set';
+
+has schema => (
+  isa      => 'DBIx::Class::Schema',
+  is       => 'ro',
+  required => 1,
+  handles => [qw( ddl_filename schema_version )],
+);
+
+has version_rs => (
+  isa        => 'DBIx::Class::ResultSet',
+  is         => 'ro',
+  lazy_build => 1,
+  handles    => [qw( is_installed db_version )],
+);
+
+sub _build_version_rs {
+   $_[0]->schema->set_us_up_the_bomb;
+   $_[0]->schema->resultset('__VERSION')
+}
+
+has to_version => (
+  is         => 'ro',
+  lazy_build => 1,
+);
+
+sub _build_to_version { $_[0]->schema->schema_version }
+
+1;
+
+__END__
+
+# normally a VersionHandler will take
+# a to_version and yeild an iterator of
+# "version sets" or something like that.
+#
+# A "version set" is basically an arrayref
+# of "version numbers" (which we already know
+# is vague as is.)  Typically an call to a
+# VH w/ a db version of 1 and a "to_version"
+# of 5 will iterate over something like this:
+# [1, 2]
+# [2, 3]
+# [3, 4]
+# [4, 5]
+#
+# Of course rob wants to be able to have dep
+# management with his versions, so I *think* his
+# would work like this:
+#
+# to_version = 7, db_version = 1
+# [1]
+# [5]
+# [7]
+#
+# Because 7 depended on 5, 5 was installed first;
+# note that this potentially never released module
+# doesn't use version pairs, instead it just yeilds
+# versions.  Version pairs are too much work for users
+# to have to deal with in that sitation.  We may
+# actually switch to this for other versioners.
+#
+# The upshot of all this is that the DeploymentMethod
+# needs to be able to take an ArrayRef[VersionNumber],
+# instead of just a pair of VersionNumber.
+vim: ts=2 sw=2 expandtab