X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FSQL%2FAbstract%2FExtraClauses.pm;h=39e6f51103ae9f65c019ef42e4d702b336e120a9;hb=e67751dd9effc7f5066e264c1d6149613a7efa42;hp=27f82b6e96bb2446766d6816d36c05effed912e2;hpb=ec44a4161fbe0369002cdf8aaac0930fddf787f0;p=scpubgit%2FQ-Branch.git

diff --git a/lib/SQL/Abstract/ExtraClauses.pm b/lib/SQL/Abstract/ExtraClauses.pm
index 27f82b6..39e6f51 100644
--- a/lib/SQL/Abstract/ExtraClauses.pm
+++ b/lib/SQL/Abstract/ExtraClauses.pm
@@ -5,19 +5,39 @@ use Moo;
 has sqla => (
   is => 'ro', init_arg => undef,
   handles => [ qw(
-    expand_expr expand_maybe_list_expr render_aqt
-    format_keyword join_query_parts
+    expand_expr expand_maybe_list_expr render_aqt join_query_parts
   ) ],
 );
 
 sub cb {
-  my ($self, $method) = @_;
-  return sub { local $self->{sqla} = shift; $self->$method(@_) };
+  my ($self, $method, @args) = @_;
+  return sub {
+    local $self->{sqla} = shift;
+    $self->$method(@args, @_)
+  };
+}
+
+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) {
@@ -29,21 +49,25 @@ 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]) },
+    ],
+    (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' ],
   );
-  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'));
 
   $sqla->clauses_of(update => sub {
     my ($self, @clauses) = @_;
@@ -58,10 +82,8 @@ sub apply_to {
   });
 
   $sqla->clause_expanders(
-    'update.from' => $self->cb('_expand_select_clause_from'),
-    'delete.using' => $self->cb(sub {
-      +(using => $_[0]->_expand_from_list(undef, $_[2]));
-    }),
+    '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] }));
     }),
@@ -72,24 +94,12 @@ sub apply_to {
 
   # set ops
   $sqla->wrap_expander(select => sub {
-    my $orig = shift;
-    $self->cb(sub {
-      my $self = shift;
-      my $exp = $self->sqla->$orig(@_);
-      return $exp unless my $setop = (my $sel = $exp->{-select})->{setop};
-      if (my @keys = grep $sel->{$_}, @before_setop) {
-        my %inner; @inner{@keys} = delete @{$sel}{@keys};
-        unshift @{(values(%$setop))[0]{queries}},
-          { -select => \%inner };
-      }
-      return $exp;
-    });
+    $self->cb('_expand_select', $_[0], \@before_setop);
   });
 
-  $sqla->clause_renderer('select.setop' => $self->cb(sub {
-    my ($self, undef, $setop) = @_;
-    $self->render_aqt($setop);
-  }));
+  $sqla->clause_renderer(
+    'select.setop' => $self->cb(sub { $_[0]->render_aqt($_[2]); })
+  );
 
   foreach my $setop (qw(union intersect except)) {
     $sqla->expander($setop => $self->cb('_expand_setop'));
@@ -118,10 +128,8 @@ sub apply_to {
     $sqla->clause_renderer("${stmt}.with" => $w_rdr);
   }
 
-  $sqla->expander(cast => $self->cb('_expand_cast'));
-
   $sqla->clause_expanders(
-    "select.from", $self->cb('_expand_select_clause_from'),
+    "select.from", $self->cb('_expand_from_list'),
     "update.target", $self->cb('_expand_update_clause_target'),
     "update.update", $self->cb('_expand_update_clause_target'),
   );
@@ -129,9 +137,16 @@ sub apply_to {
   return $sqla;
 }
 
-sub _expand_select_clause_from {
-  my ($self, undef, $from) = @_;
-  +(from => $self->_expand_from_list(undef, $from));
+sub _expand_select {
+  my ($self, $orig, $before_setop, @args) = @_;
+  my $exp = $self->sqla->$orig(@args);
+  return $exp unless my $setop = (my $sel = $exp->{-select})->{setop};
+  if (my @keys = grep $sel->{$_}, @$before_setop) {
+    my %inner; @inner{@keys} = delete @{$sel}{@keys};
+    unshift @{(values(%$setop))[0]{queries}},
+      { -select => \%inner };
+  }
+  return $exp;
 }
 
 sub _expand_from_list {
@@ -192,14 +207,14 @@ sub _render_join {
 
   my @parts = (
     $args->{from},
-    $self->format_keyword(join '_', ($args->{type}||()), 'join'),
+    { -keyword => join '_', ($args->{type}||()), 'join' },
     (map +($_->{-ident} || $_->{-as} ? $_ : ('(', $_, ')')), $args->{to}),
     ($args->{on} ? (
-      $self->format_keyword('on') ,
+      { -keyword => 'on' },
       $args->{on},
     ) : ()),
     ($args->{using} ? (
-      $self->format_keyword('using'),
+      { -keyword => 'using' },
       '(', $args->{using}, ')',
     ) : ()),
   );
@@ -209,7 +224,6 @@ sub _render_join {
 sub _expand_op_as {
   my ($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';
@@ -224,7 +238,7 @@ sub _render_as {
   return $self->join_query_parts(
     ' ',
     $thing,
-    $self->format_keyword('as'),
+    { -keyword => 'as' },
     $alias,
   );
 }
@@ -305,13 +319,13 @@ sub _render_with {
       my ($alias, $query) = @$_;
       $self->join_query_parts(' ',
           $alias,
-          $self->format_keyword('as'),
+          { -keyword => 'as' },
           $query,
       )
     } @{$with->{queries}}
   );
   return $self->join_query_parts(' ',
-    $self->format_keyword(join '_', 'with', ($with->{type}||'')),
+    { -keyword => join '_', 'with', ($with->{type}||'') },
     $q_part,
   );
 }
@@ -327,7 +341,7 @@ sub _expand_setop {
 sub _render_setop {
   my ($self, $setop, $args) = @_;
   $self->join_query_parts(
-    ' '.$self->format_keyword(join '_', $setop, ($args->{type}||())).' ',
+    { -keyword => ' '.join('_', $setop, ($args->{type}||())).' ' },
     @{$args->{queries}}
   );
 }
@@ -344,3 +358,101 @@ 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 cb
+
+For plugin authors, creates a callback to call a method on the plugin.
+
+=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