X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSQL%2FAbstract%2FExtraClauses.pm;h=c0e753dd75a03fe1a1b1cd99a66c2ab0e266ff6c;hb=ec49a2e10ad2cca513719dc04f410fb9cae85978;hp=e0b253292119d34b557e00f5d56e6fe2dbd2a94a;hpb=3001f09746dcc5164c040fcbb5d87d454f61c726;p=scpubgit%2FQ-Branch.git

diff --git a/lib/SQL/Abstract/ExtraClauses.pm b/lib/SQL/Abstract/ExtraClauses.pm
index e0b2532..c0e753d 100644
--- a/lib/SQL/Abstract/ExtraClauses.pm
+++ b/lib/SQL/Abstract/ExtraClauses.pm
@@ -17,9 +17,25 @@ sub cb {
   };
 }
 
+sub register {
+  my ($self, $method, @pairs) = @_;
+  my $sqla = $self->sqla;
+  while (my ($car, $cdr) = splice(@pairs, 0, 2)) {
+    my $cb = $self->cb($cdr);
+    $sqla->$method($car, $cb);
+  }
+  return $self;
+}
+
 sub apply_to {
   my ($self, $sqla) = @_;
   $self = $self->new unless ref($self);
+  local $self->{sqla} = $sqla;
+  $self->register_extensions($sqla);
+}
+
+sub register_extensions {
+  my ($self, $sqla) = @_;
   my @clauses = $sqla->clauses_of('select');
   my @before_setop;
   CLAUSE: foreach my $idx (0..$#clauses) {
@@ -31,11 +47,12 @@ sub apply_to {
   }
   die "Huh?" unless @before_setop;
   $sqla->clauses_of(select => 'with', @clauses);
-  $sqla->clause_expanders(
-    'select.group_by', $self->cb(sub {
-      $_[0]->expand_maybe_list_expr($_[2], -ident)
-    }),
-    'select.having', $self->cb(sub { $_[0]->expand_expr($_[2]) }),
+  $self->register(
+    clause_expanders =>
+      'select.group_by'
+        => sub { $_[0]->expand_maybe_list_expr($_[2], -ident) },
+      'select.having'
+        => sub { $_[0]->expand_expr($_[2]) },
   );
   foreach my $thing (qw(join from_list)) {
     $sqla->expander($thing => $self->cb("_expand_${thing}"))
@@ -338,6 +355,8 @@ sub _expand_clause_setop {
 
 1;
 
+__END__
+
 =head1 NAME
 
 SQL::Abstract::ExtraClauses - new/experimental additions to L<SQL::Abstract>
@@ -362,4 +381,74 @@ For plugin authors, creates a callback to call a method on the plugin.
 Available only during plugin callback executions, contains the currently
 active L<SQL::Abstract> object.
 
+=head1 NODE TYPES
+
+=head2 alias
+
+Represents a table alias. Expands name and column names with ident as default.
+
+  # expr
+  { -alias => [ 't', 'x', 'y', 'z' ] }
+
+  # aqt
+  { -alias => [
+      { -ident => [ 't' ] }, { -ident => [ 'x' ] },
+      { -ident => [ 'y' ] }, { -ident => [ 'z' ] },
+  ] }
+
+  # query
+  t(x, y, z)
+  []
+
+=head2 as
+
+Represents an sql AS. LHS is expanded with ident as default, RHS is treated
+as a list of arguments for the alias node.
+
+  # expr
+  { foo => { -as => 'bar' } }
+
+  # aqt
+  { -as =>
+      [
+        { -ident => [ 'foo' ] },
+        { -alias => [ { -ident => [ 'bar' ] } ] },
+      ]
+  }
+
+  # query
+  foo AS bar
+  []
+
+  # expr
+  { -as => [ { -select => { _ => 'blah' } }, 't', 'blah' ] }
+
+  # aqt
+  { -as => [
+      { -select =>
+          { select => { -op => [ ',', { -ident => [ 'blah' ] } ] } }
+      },
+      { -alias => [ { -ident => [ 't' ] }, { -ident => [ 'blah' ] } ] },
+  ] }
+
+  # query
+  (SELECT blah) AS t(blah)
+  []
+
+=head2 cast
+
+  # expr
+  { -cast => [ { -ident => 'birthday' }, 'date' ] }
+
+  # aqt
+  { -func => [
+      'cast', {
+        -as => [ { -ident => [ 'birthday' ] }, { -ident => [ 'date' ] } ]
+      },
+  ] }
+
+  # query
+  CAST(birthday AS date)
+  []
+
 =cut