X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSQL%2FAbstract%2FExtraClauses.pm;h=358cdf16f7e0ae0dd3e50669eb3d6c7ed3254ab3;hb=f1c52c0c610ec999b831c3a105d27c5b6f839a56;hp=57faed739a5577ba7ea94939441c3b5d6d20b2ac;hpb=1601bb47472f6eb2ca3633935bbf3f3399e78604;p=scpubgit%2FQ-Branch.git

diff --git a/lib/SQL/Abstract/ExtraClauses.pm b/lib/SQL/Abstract/ExtraClauses.pm
index 57faed7..358cdf1 100644
--- a/lib/SQL/Abstract/ExtraClauses.pm
+++ b/lib/SQL/Abstract/ExtraClauses.pm
@@ -17,9 +17,28 @@ sub cb {
   };
 }
 
+sub register {
+  my ($self, @pairs) = @_;
+  my $sqla = $self->sqla;
+  while (my ($method, $cases) = splice(@pairs, 0, 2)) {
+    my @cases = @$cases;
+    while (my ($name, $case) = splice(@cases, 0, 2)) {
+      $sqla->$method($name, $self->cb($case));
+    }
+  }
+  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) {
@@ -29,23 +48,9 @@ sub apply_to {
       last CLAUSE;
     }
   }
+
   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]) }),
-  );
-  foreach my $thing (qw(join from_list)) {
-    $sqla->expander($thing => $self->cb("_expand_${thing}"))
-         ->renderer($thing => $self->cb("_render_${thing}"))
-  }
-  $sqla->op_expander(as => $self->cb('_expand_op_as'));
-  $sqla->expander(as => $self->cb('_expand_op_as'));
-  $sqla->renderer(as => $self->cb('_render_as'));
-  $sqla->expander(alias => $self->cb('_expand_alias'));
-  $sqla->renderer(alias => $self->cb('_render_alias'));
+  $sqla->clauses_of(select => @clauses);
 
   $sqla->clauses_of(update => sub {
     my ($self, @clauses) = @_;
@@ -59,15 +64,35 @@ sub apply_to {
     @clauses;
   });
 
-  $sqla->clause_expanders(
-    'update.from' => $self->cb('_expand_from_list'),
-    'delete.using' => $self->cb('_expand_from_list'),
-    'insert.rowvalues' => $self->cb(sub {
-      +(from => $_[0]->expand_expr({ -values => $_[2] }));
-    }),
-    'insert.select' => $self->cb(sub {
-      +(from => $_[0]->expand_expr({ -select => $_[2] }));
-    }),
+  $self->register(
+    (map +(
+      "${_}er" => [
+        do {
+          my $x = $_;
+          (map +($_ => "_${x}_${_}"), qw(join from_list alias))
+        }
+       ]
+    ), qw(expand render)),
+    binop_expander => [ as => '_expand_op_as' ],
+    renderer => [ as => '_render_as' ],
+    expander => [ cast => '_expand_cast' ],
+    clause_expanders => [
+      "select.from", '_expand_from_list',
+      'select.group_by'
+        => sub { $_[0]->expand_maybe_list_expr($_[2], -ident) },
+      'select.having'
+        => sub { $_[0]->expand_expr($_[2]) },
+      'update.from' => '_expand_from_list',
+      "update.target", '_expand_update_clause_target',
+      "update.update", '_expand_update_clause_target',
+      'delete.using' => '_expand_from_list',
+      'insert.rowvalues' => sub {
+        +(from => $_[0]->expand_expr({ -values => $_[2] }));
+      },
+      'insert.select' => sub {
+        +(from => $_[0]->expand_expr({ -select => $_[2] }));
+      },
+    ],
   );
 
   # set ops
@@ -75,15 +100,14 @@ sub apply_to {
     $self->cb('_expand_select', $_[0], \@before_setop);
   });
 
-  $sqla->clause_renderer(
-    'select.setop' => $self->cb(sub { $_[0]->render_aqt($_[2]); })
+  $self->register(
+    clause_renderer => [
+      'select.setop' => sub { $_[0]->render_aqt($_[2]) }
+    ],
+    expander => [ map +($_ => '_expand_setop'), qw(union intersect except) ],
+    renderer => [ map +($_ => '_render_setop'), qw(union intersect except) ],
   );
 
-  foreach my $setop (qw(union intersect except)) {
-    $sqla->expander($setop => $self->cb('_expand_setop'));
-    $sqla->renderer($setop => $self->cb('_render_setop'));
-  }
-
   my $setop_expander = $self->cb('_expand_clause_setop');
 
   $sqla->clause_expanders(
@@ -93,27 +117,17 @@ sub apply_to {
           qw(union intersect except)
   );
 
-  my $w_exp = $self->cb('_expand_with');
-  my $w_rdr = $self->cb('_render_with');
-  $sqla->clause_expander('select.with' => $w_exp);
-  $sqla->clause_expander('select.with_recursive' => $w_exp);
-  $sqla->clause_renderer('select.with' => $w_rdr);
-
-  foreach my $stmt (qw(insert update delete)) {
+  foreach my $stmt (qw(select insert update delete)) {
     $sqla->clauses_of($stmt => 'with', $sqla->clauses_of($stmt));
-    $sqla->clause_expander("${stmt}.$_" => $w_exp)
-      for qw(with with_recursive);
-    $sqla->clause_renderer("${stmt}.with" => $w_rdr);
+    $self->register(
+      clause_expanders => [
+        "${stmt}.with" => '_expand_with',
+        "${stmt}.with_recursive" => '_expand_with',
+      ],
+      clause_renderer => [ "${stmt}.with" => '_render_with' ],
+    );
   }
 
-  $sqla->expander(cast => $self->cb('_expand_cast'));
-
-  $sqla->clause_expanders(
-    "select.from", $self->cb('_expand_from_list'),
-    "update.target", $self->cb('_expand_update_clause_target'),
-    "update.update", $self->cb('_expand_update_clause_target'),
-  );
-
   return $sqla;
 }
 
@@ -204,7 +218,6 @@ sub _render_join {
 sub _expand_op_as {
   my ($self, undef, $vv, $k) = @_;
   my @vv = (ref($vv) eq 'ARRAY' ? @$vv : $vv);
-  $k ||= shift @vv;
   my $ik = $self->expand_expr($k, -ident);
   return +{ -as => [ $ik, $self->expand_expr($vv[0], -alias) ] }
     if @vv == 1 and ref($vv[0]) eq 'HASH';
@@ -339,3 +352,109 @@ sub _expand_clause_setop {
 }
 
 1;
+
+__END__
+
+=head1 NAME
+
+SQL::Abstract::ExtraClauses - new/experimental additions to L<SQL::Abstract>
+
+=head1 SYNOPSIS
+
+  my $sqla = SQL::Abstract->new;
+  SQL::Abstract::ExtraClauses->apply_to($sqla);
+
+=head1 METHODS
+
+=head2 apply_to
+
+Applies the plugin to an L<SQL::Abstract> object.
+
+=head2 register_extensions
+
+Registers the extensions described below
+
+=head2 cb
+
+For plugin authors, creates a callback to call a method on the plugin.
+
+=head2 register
+
+For plugin authors, registers callbacks more easily.
+
+=head2 sqla
+
+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