lib/SQL/Translator/Producer/ClassDBI.pm

   1 package SQL::Translator::Producer::ClassDBI;
   2
   3 # -------------------------------------------------------------------
   4 # $Id: ClassDBI.pm,v 1.28 2003-07-09 17:48:12 allenday Exp $
   5 # -------------------------------------------------------------------
   6 # Copyright (C) 2003 Allen Day <allenday@ucla.edu>,
   7 #                    Ying Zhang <zyolive@yahoo.com>
   8 #
   9 # This program is free software; you can redistribute it and/or
  10 # modify it under the terms of the GNU General Public License as
  11 # published by the Free Software Foundation; version 2.
  12 #
  13 # This program is distributed in the hope that it will be useful, but
  14 # WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 # General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program; if not, write to the Free Software
  20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  21 # 02111-1307  USA
  22 # -------------------------------------------------------------------
  23
  24 use strict;
  25 use vars qw[ $VERSION $DEBUG ];
  26 $VERSION = sprintf "%d.%02d", q$Revision: 1.28 $ =~ /(\d+)\.(\d+)/;
  27 $DEBUG   = 1 unless defined $DEBUG;
  28
  29 use SQL::Translator::Schema::Constants;
  30 use SQL::Translator::Utils qw(header_comment);
  31 use Data::Dumper;
  32
  33 my %CDBI_auto_pkgs = (
  34     MySQL      => 'mysql',
  35     PostgreSQL => 'Pg',
  36     Oracle     => 'Oracle',
  37 );
  38
  39 # -------------------------------------------------------------------
  40 sub produce {
  41     my $t             = shift;
  42         my $create        = undef;
  43     local $DEBUG      = $t->debug;
  44     my $no_comments   = $t->no_comments;
  45     my $schema        = $t->schema;
  46     my $args          = $t->producer_args;
  47     my $db_user       = $args->{'db_user'} || '';
  48     my $db_pass       = $args->{'db_pass'} || '';
  49     my $main_pkg_name = $t->format_package_name('DBI');
  50     my $header        = header_comment(__PACKAGE__, "# ");
  51     my $parser_type   = ( split /::/, $t->parser_type )[-1];
  52     my $from          = $CDBI_auto_pkgs{ $parser_type } || '';
  53     my $dsn           = $args->{'dsn'} || sprintf( 'dbi:%s:_',
  54                             $CDBI_auto_pkgs{ $parser_type }
  55                             ? $CDBI_auto_pkgs{ $parser_type } : $parser_type
  56                         );
  57     my $sep           = '# ' . '-' x 67;
  58
  59     #
  60     # Identify "link tables" (have only PK and FK fields).
  61     #
  62     my %linkable;
  63     my %linktable;
  64     foreach my $table ( $schema->get_tables ) {
  65         my $is_link = 1;
  66         foreach my $field ( $table->get_fields ) {
  67             unless ( $field->is_primary_key or $field->is_foreign_key ) {
  68                 $is_link = 0;
  69                 last;
  70             }
  71         }
  72
  73         next unless $is_link;
  74
  75         foreach my $left ( $table->get_fields ) {
  76             next unless $left->is_foreign_key;
  77             my $lfk           = $left->foreign_key_reference or next;
  78             my $lr_table      = $schema->get_table( $lfk->reference_table )
  79                                  or next;
  80             my $lr_field_name = ($lfk->reference_fields)[0];
  81             my $lr_field      = $lr_table->get_field($lr_field_name);
  82             next unless $lr_field->is_primary_key;
  83
  84             foreach my $right ( $table->get_fields ) {
  85                 next if $left->name eq $right->name;
  86
  87                 my $rfk      = $right->foreign_key_reference or next;
  88                 my $rr_table = $schema->get_table( $rfk->reference_table )
  89                                or next;
  90                 my $rr_field_name = ($rfk->reference_fields)[0];
  91                 my $rr_field      = $rr_table->get_field($rr_field_name);
  92                 next unless $rr_field->is_primary_key;
  93
  94                 $linkable{ $lr_table->name }{ $rr_table->name } = $table;
  95                 $linkable{ $rr_table->name }{ $lr_table->name } = $table;
  96                 $linktable{ $table->name } = $table;
  97             }
  98         }
  99     }
 100
 101     #
 102     # Iterate over all tables
 103     #
 104     my ( %packages, $order );
 105     for my $table ( $schema->get_tables ) {
 106         my $table_name = $table->name or next;
 107
 108         my $table_pkg_name = $t->format_package_name($table_name);
 109         $packages{ $table_pkg_name } = {
 110             order     => ++$order,
 111             pkg_name  => $table_pkg_name,
 112             base      => $main_pkg_name,
 113             table     => $table_name,
 114         };
 115
 116         #
 117         # Primary key may have a differenct accessor method name
 118         #
 119         if ( my $pk_xform = $t->format_pk_name ) {
 120             if ( my $constraint = $table->primary_key ) {
 121                 my $field          = ($constraint->fields)[0];
 122                 my $pk_name        = $pk_xform->($table_pkg_name, $field);
 123
 124                 $packages{ $table_pkg_name }{'pk_accessor'} =
 125                     "#\n# Primary key accessor\n#\n".
 126                     "sub $pk_name {\n    shift->$field\n}\n\n"
 127                 ;
 128             }
 129         }
 130
 131         my $is_data = 0;
 132         foreach my $field ( $table->get_fields ) {
 133                   $is_data++ if !$field->is_foreign_key and !$field->is_primary_key;
 134                 }
 135
 136                 my %linked;
 137                 if ( $is_data ) {
 138                   foreach my $link ( keys %{ $linkable{ $table_name } } ) {
 139                         my $linkmethodname;
 140
 141                         if ( my $fk_xform = $t->format_fk_name ) {
 142                           # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 143                           $linkmethodname = $fk_xform->($linkable{$table_name}{$link}->name,
 144                                                                                         ($schema->get_table($link)->primary_key->fields)[0]).'s';
 145                         } else {
 146                           # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 147                           $linkmethodname = $linkable{$table_name}{$link}->name.'_'.
 148                                 ($schema->get_table($link)->primary_key->fields)[0].'s';
 149                         }
 150
 151                         my @rk_fields = ();
 152                         my @lk_fields = ();
 153                         foreach my $field ($linkable{$table_name}{$link}->get_fields) {
 154                           next unless $field->is_foreign_key;
 155
 156                           next unless(
 157                                                   $field->foreign_key_reference->reference_table eq $table_name
 158                                                   ||
 159                                                   $field->foreign_key_reference->reference_table eq $link
 160                                                  );
 161                           push @lk_fields, ($field->foreign_key_reference->reference_fields)[0]
 162                                 if $field->foreign_key_reference->reference_table eq $link;
 163                           push @rk_fields, $field->name
 164                                 if $field->foreign_key_reference->reference_table eq $table_name;
 165                         }
 166
 167                         #if one possible traversal via link table
 168                         if (scalar(@rk_fields) == 1 and scalar(@lk_fields) == 1) {
 169                           foreach my $rk_field (@rk_fields) {
 170                                 push @{ $packages{ $table_pkg_name }{'has_many'}{ $link } },
 171                                   "sub ".$linkmethodname." { my \$self = shift; ".
 172                                         "return map \$_->".
 173                                           ($schema->get_table($link)->primary_key->fields)[0].
 174                                                 ", \$self->".$linkable{$table_name}{$link}->name.
 175                                                   "_".$rk_field." }\n\n";
 176                           }
 177                           #else there is more than one way to traverse it.  ack!
 178                           #let's treat these types of link tables as a many-to-one (easier)
 179                           #
 180                           #NOTE: we need to rethink the link method name, as the cardinality
 181                           #has shifted on us.
 182                         } elsif (scalar(@rk_fields) == 1) {
 183                           foreach my $rk_field (@rk_fields) {
 184                                 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 185                                 push @{ $packages{ $table_pkg_name }{'has_many'}{ $link } },
 186                                   "sub " . $linkable{$table_name}{$link}->name .
 187                                         "s { my \$self = shift; return \$self->" .
 188                                           $linkable{$table_name}{$link}->name . "_" .
 189                                                 $rk_field . "(\@_) }\n\n";
 190                           }
 191                         } elsif (scalar(@lk_fields) == 1) {
 192                           #these will be taken care of on the other end...
 193                         } else {
 194                           #many many many.  need multiple iterations here, data structure revision
 195                           #to handle N FK sources.  This code has not been tested and likely doesn't
 196                           #work here
 197                           foreach my $rk_field (@rk_fields) {
 198                                 # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 199                                 push @{ $packages{ $table_pkg_name }{'has_many'}{ $link } },
 200                                   "sub " . $linkable{$table_name}{$link}->name . "_" . $rk_field .
 201                                         "s { my \$self = shift; return \$self->" .
 202                                           $linkable{$table_name}{$link}->name . "_" .
 203                                                 $rk_field . "(\@_) }\n\n";
 204                           }
 205                         }
 206                   }
 207         }
 208
 209
 210         #
 211         # Use foreign keys to set up "has_a/has_many" relationships.
 212         #
 213         foreach my $field ( $table->get_fields ) {
 214             if ( $field->is_foreign_key ) {
 215                 my $table_name = $table->name;
 216                 my $field_name = $field->name;
 217                 my $fk_method  = $t->format_fk_name($table_name, $field_name);
 218                 my $fk         = $field->foreign_key_reference;
 219                 my $ref_table  = $fk->reference_table;
 220                 my $ref_pkg    = $t->format_package_name($ref_table);
 221                 my $ref_field  = ($fk->reference_fields)[0];
 222
 223                 push @{ $packages{ $table_pkg_name }{'has_a'} },
 224                     "$table_pkg_name->has_a(\n".
 225                     "    $field_name => '$ref_pkg'\n);\n\n".
 226                     "sub $fk_method {\n".
 227                     "    return shift->$field_name\n}\n\n"
 228                 ;
 229
 230                 #
 231                 # If this table "has a" to the other, then it follows
 232                 # that the other table "has many" of this one, right?
 233                 #
 234                                 # No... there is the possibility of 1-1 cardinality
 235
 236                                 #if there weren't M-M relationships via the has_many
 237                                 #being set up here, create nice pluralized method alias
 238                                 #rather for user as alt. to ugly tablename_fieldname name
 239                                 if(! $packages{ $ref_pkg }{ 'has_many' }{ $table_name } ){
 240                                   # ADD CALLBACK FOR PLURALIZATION MANGLING HERE
 241                                   push @{ $packages{ $ref_pkg }{'has_many'}{ $table_name } },
 242                                         "sub $table_name\s {\n    return shift->$table_name\_$field_name\n}\n\n";
 243
 244                                 #else ugly
 245                                 } else {
 246                                 }
 247
 248                                 push @{ $packages{ $ref_pkg }{'has_many'}{ $table_name } },
 249                                   "$ref_pkg->has_many(\n    '${table_name}_${field_name}', ".
 250                                   "'$table_pkg_name' => '$field_name'\n);\n\n";
 251
 252             }
 253                 }
 254         }
 255
 256     #
 257     # Now build up text of package.
 258     #
 259     my $base_pkg = sprintf( 'Class::DBI%s', $from ? "::$from" : '' );
 260     $create .= join("\n",
 261       "package $main_pkg_name;\n",
 262       $header,
 263       "use strict;",
 264       "use base '$base_pkg';\n",
 265       "$main_pkg_name->set_db('Main', '$dsn', '$db_user', '$db_pass');\n\n",
 266     );
 267
 268     for my $pkg_name (
 269         sort { $packages{ $a }{'order'} <=> $packages{ $b }{'order'} }
 270         keys %packages
 271     ) {
 272         my $pkg = $packages{ $pkg_name };
 273
 274         $create .= join("\n",
 275             $sep,
 276             "package ".$pkg->{'pkg_name'}.";",
 277             "use base '".$pkg->{'base'}."';",
 278             "use Class::DBI::Pager;\n\n",
 279         );
 280
 281         if ( $from ) {
 282             $create .=
 283                 $pkg->{'pkg_name'}."->set_up_table('".$pkg->{'table'}."');\n\n";
 284         }
 285         else {
 286             my $table       = $schema->get_table( $pkg->{'table'} );
 287             my @field_names = map { $_->name } $table->get_fields;
 288
 289             $create .= join("\n",
 290                 $pkg_name."->table('".$pkg->{'table'}."');\n",
 291                 $pkg_name."->columns(All => qw/".
 292                 join(' ', @field_names)."/);\n\n",
 293             );
 294         }
 295
 296         if ( my $pk = $pkg->{'pk_accessor'} ) {
 297             $create .= $pk;
 298         }
 299
 300         if ( my @has_a = @{ $pkg->{'has_a'} || [] } ) {
 301             $create .= $_ for @has_a;
 302         }
 303
 304                 foreach my $has_many_key (keys %{ $pkg->{'has_many'} }){
 305                   if ( my @has_many = @{ $pkg->{'has_many'}{ $has_many_key } || [] } ) {
 306             $create .= $_ for @has_many;
 307                   }
 308                 }
 309     }
 310
 311     $create .= "1;\n";
 312
 313     return $create;
 314 }
 315
 316 1;
 317
 318 # -------------------------------------------------------------------
 319
 320 =pod
 321
 322 =head1 NAME
 323
 324 SQL::Translator::Producer::ClassDBI - create Class::DBI classes from schema
 325
 326 =head1 SYNOPSIS
 327
 328 Use this producer as you would any other from SQL::Translator.  See
 329 L<SQL::Translator> for details.
 330
 331 This package utilizes SQL::Translator's formatting methods
 332 format_package_name(), format_pk_name(), format_fk_name(), and
 333 format_table_name() as it creates classes, one per table in the schema
 334 provided.  An additional base class is also created for database connectivity
 335 configuration.  See L<Class::DBI> for details on how this works.
 336
 337 =head1 AUTHORS
 338
 339 Allen Day E<lt>allenday@ucla.eduE<gt>
 340 Ying Zhang E<lt>zyolive@yahoo.comE<gt>,
 341 Ken Y. Clark E<lt>kclark@cpan.org<gt>.