X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=scpubgit%2FQ-Branch.git;a=blobdiff_plain;f=lib%2FSQL%2FAbstract%2FExtraClauses.pm;h=9c2784539387247910d19bae5ebb0f6646d86758;hp=8ff2b748759567fff29d521bd00574ecb2cda214;hb=4979c509c66eb5c81887d3afe37de54f0988ad94;hpb=583c795782989e08ee7fabdb9626c93428131e1e

diff --git a/lib/SQL/Abstract/ExtraClauses.pm b/lib/SQL/Abstract/ExtraClauses.pm
index 8ff2b74..9c27845 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) {
@@ -29,22 +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->binop_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) = @_;
@@ -58,15 +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
@@ -74,15 +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(
@@ -92,27 +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;
 }
 
@@ -152,6 +167,7 @@ sub _expand_from_list {
     }
     push @list, $aqt;
   }
+  return $list[0] if @list == 1;
   return { -from_list => \@list };
 }
 
@@ -160,10 +176,12 @@ sub _expand_join {
   my %proto = (
     ref($args) eq 'HASH'
       ? %$args
-      : (to => $args->[0], @{$args}[1..$#$args])
+      : (to => @$args)
   );
   if (my $as = delete $proto{as}) {
-    $proto{to} = $self->expand_expr({ -as => [ $proto{to}, $as ] });
+    $proto{to} = $self->expand_expr(
+                   { -as => [ { -from_list => $proto{to} }, $as ] }
+                 );
   }
   if (defined($proto{using}) and ref(my $using = $proto{using}) ne 'HASH') {
     $proto{using} = [
@@ -171,8 +189,14 @@ sub _expand_join {
         ref($using) eq 'ARRAY' ? @$using: $using
     ];
   }
-  my %ret = map +($_ => $self->expand_expr($proto{$_}, -ident)),
-              sort keys %proto;
+  my %ret = (
+    type => delete $proto{type},
+    to => $self->expand_expr({ -from_list => delete $proto{to} }, -ident)
+  );
+  %ret = (%ret,
+    map +($_ => $self->expand_expr($proto{$_}, -ident)),
+      sort keys %proto
+  );
   return +{ -join => \%ret };
 }
 
@@ -187,7 +211,12 @@ sub _render_join {
   my @parts = (
     $args->{from},
     { -keyword => join '_', ($args->{type}||()), 'join' },
-    (map +($_->{-ident} || $_->{-as} ? $_ : ('(', $_, ')')), $args->{to}),
+    (map +($_->{-ident} || $_->{-as}
+      ? $_
+      : ('(', $self->render_aqt($_, 1), ')')),
+        map +(@{$_->{-from_list}||[]} == 1 ? $_->{-from_list}[0] : $_),
+          $args->{to}
+    ),
     ($args->{on} ? (
       { -keyword => 'on' },
       $args->{on},
@@ -204,11 +233,11 @@ sub _expand_op_as {
   my ($self, undef, $vv, $k) = @_;
   my @vv = (ref($vv) eq 'ARRAY' ? @$vv : $vv);
   my $ik = $self->expand_expr($k, -ident);
-  return +{ -as => [ $ik, $self->expand_expr($vv[0], -alias) ] }
+  return +{ -as => [ $ik, $self->expand_expr($vv[0], -ident) ] }
     if @vv == 1 and ref($vv[0]) eq 'HASH';
 
   my @as = map $self->expand_expr($_, -ident), @vv;
-  return { -as => [ $ik, { -alias => \@as } ] };
+  return { -as => [ $ik, $self->expand_expr({ -alias => \@as }) ] };
 }
 
 sub _render_as {
@@ -259,11 +288,10 @@ sub _expand_alias {
   if (ref($args) eq 'HASH' and my $alias = $args->{-alias}) {
     $args = $alias;
   }
-  +{ -alias => [
-      map $self->expand_expr($_, -ident),
-      ref($args) eq 'ARRAY' ? @{$args} : $args
-    ]
-  }
+  my @parts = map $self->expand_expr($_, -ident),
+                ref($args) eq 'ARRAY' ? @{$args} : $args;
+  return $parts[0] if @parts == 1;
+  return { -alias => \@parts };
 }
 
 sub _expand_with {
@@ -355,10 +383,18 @@ SQL::Abstract::ExtraClauses - new/experimental additions to L<SQL::Abstract>
 
 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
@@ -392,12 +428,7 @@ as a list of arguments for the alias node.
   { foo => { -as => 'bar' } }
 
   # aqt
-  { -as =>
-      [
-        { -ident => [ 'foo' ] },
-        { -alias => [ { -ident => [ 'bar' ] } ] },
-      ]
-  }
+  { -as => [ { -ident => [ 'foo' ] }, { -ident => [ 'bar' ] } ] }
 
   # query
   foo AS bar
@@ -434,4 +465,114 @@ as a list of arguments for the alias node.
   CAST(birthday AS date)
   []
 
+=head2 join
+
+If given an arrayref, pretends it was given a hashref with the first
+element of the arrayref as the value for 'to' and the remaining pairs copied.
+
+Given a hashref, the 'as' key is if presented expanded to wrap the 'to'.
+
+If present the 'using' key is expanded as a list of idents.
+
+Known keys are: 'from' (the left hand side), 'type' ('left', 'right', or
+nothing), 'to' (the right hand side), 'on' and 'using'.
+
+  # expr
+  { -join => {
+      from => 'lft',
+      on => { 'lft.bloo' => { '>' => 'rgt.blee' } },
+      to => 'rgt',
+      type => 'left',
+  } }
+
+  # aqt
+  { -join => {
+      from => { -ident => [ 'lft' ] },
+      on => { -op => [
+          '>', { -ident => [ 'lft', 'bloo' ] },
+          { -ident => [ 'rgt', 'blee' ] },
+      ] },
+      to => { -ident => [ 'rgt' ] },
+      type => 'left',
+  } }
+
+  # query
+  lft LEFT JOIN rgt ON lft.bloo > rgt.blee
+  []
+
+=head2 from_list
+
+List of components of the FROM clause; -foo type elements indicate a pair
+with the next element; this is easiest if I show you:
+
+  # expr
+  { -from_list => [
+      't1', -as => 'table_one', -join =>
+      [ 't2', 'on', { 'table_one.x' => 't2.x' } ],
+  ] }
+
+  # aqt
+  { -join => {
+      from =>
+        {
+          -as => [ { -ident => [ 't1' ] }, { -ident => [ 'table_one' ] } ]
+        },
+      on => { -op => [
+          '=', { -ident => [ 'table_one', 'x' ] },
+          { -ident => [ 't2', 'x' ] },
+      ] },
+      to => { -ident => [ 't2' ] },
+      type => undef,
+  } }
+
+  # query
+  t1 AS table_one JOIN t2 ON table_one.x = t2.x
+  []
+
+Or with using:
+
+  # expr
+  { -from_list =>
+      [ 't1', -as => 'table_one', -join => [ 't2', 'using', [ 'x' ] ] ]
+  }
+
+  # aqt
+  { -join => {
+      from =>
+        {
+          -as => [ { -ident => [ 't1' ] }, { -ident => [ 'table_one' ] } ]
+        },
+      to => { -ident => [ 't2' ] },
+      type => undef,
+      using =>
+        { -op => [ 'or', { -op => [ 'or', { -ident => [ 'x' ] } ] } ] },
+  } }
+
+  # query
+  t1 AS table_one JOIN t2 USING ( x )
+  []
+
+With oddities:
+
+  # expr
+  { -from_list => [
+      'x', -join =>
+      [ [ 'y', -join => [ 'z', 'type', 'left' ] ], 'type', 'left' ],
+  ] }
+
+  # aqt
+  { -join => {
+      from => { -ident => [ 'x' ] },
+      to => { -join => {
+          from => { -ident => [ 'y' ] },
+          to => { -ident => [ 'z' ] },
+          type => 'left',
+      } },
+      type => 'left',
+  } }
+
+  # query
+  x LEFT JOIN ( y LEFT JOIN z )
+  []
+
 =cut