package SQL::Translator;
# ----------------------------------------------------------------------
-# $Id: Translator.pm,v 1.9 2002-07-23 19:21:16 dlc Exp $
+# $Id: Translator.pm,v 1.16 2003-01-29 13:29:49 dlc Exp $
# ----------------------------------------------------------------------
-# Copyright (C) 2002 Ken Y. Clark <kycl4rk@users.sourceforge.net>,
-# darren chamberlain <darren@cpan.org>
+# Copyright (C) 2003 Ken Y. Clark <kclark@cpan.org>,
+# darren chamberlain <darren@cpan.org>,
+# Chris Mungall <cjm@fruitfly.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# 02111-1307 USA
# -------------------------------------------------------------------
-=head1 NAME
-
-SQL::Translator - convert schema from one database to another
-
-=head1 SYNOPSIS
-
- use SQL::Translator;
- my $translator = SQL::Translator->new;
-
- my $output = $translator->translate(
- from => "MySQL",
- to => "Oracle",
- filename => $file,
- ) or die $translator->error;
- print $output;
-
-=head1 DESCRIPTION
-
-This module attempts to simplify the task of converting one database
-create syntax to another through the use of Parsers (which understand
-the sourced format) and Producers (which understand the destination
-format). The idea is that any Parser can be used with any Producer in
-the conversion process. So, if you wanted PostgreSQL-to-Oracle, you
-would use the PostgreSQL parser and the Oracle producer.
-
-=cut
-
use strict;
-use vars qw($VERSION $DEFAULT_SUB $DEBUG $ERROR);
-use base qw(Class::Base);
+use vars qw( $VERSION $REVISION $DEFAULT_SUB $DEBUG $ERROR );
+use base 'Class::Base';
-$VERSION = sprintf "%d.%02d", q$Revision: 1.9 $ =~ /(\d+)\.(\d+)/;
-$DEBUG = 1 unless defined $DEBUG;
-$ERROR = "";
+$VERSION = '0.01';
+$REVISION = sprintf "%d.%02d", q$Revision: 1.16 $ =~ /(\d+)\.(\d+)/;
+$DEBUG = 0 unless defined $DEBUG;
+$ERROR = "";
use Carp qw(carp);
+use File::Spec::Functions qw(catfile);
+use File::Basename qw(dirname);
+use IO::Dir;
+
# ----------------------------------------------------------------------
# The default behavior is to "pass through" values (note that the
# SQL::Translator instance is the first value ($_[0]), and the stuff
# ----------------------------------------------------------------------
$DEFAULT_SUB = sub { $_[1] } unless defined $DEFAULT_SUB;
-=head1 CONSTRUCTOR
-
-The constructor is called B<new>, and accepts a optional hash of options.
-Valid options are:
-
-=over 4
-
-=item parser (aka from)
-
-=item parser_args
-
-=item producer (aka to)
-
-=item producer_args
-
-=item filename (aka file)
-
-=item data
-
-=item debug
-
-=back
-
-All options are, well, optional; these attributes can be set via
-instance methods. Internally, they are; no (non-syntactical)
-advantage is gained by passing options to the constructor.
-
-=cut
-
# ----------------------------------------------------------------------
# init([ARGS])
# The constructor.
# what each expects/accepts.
# ----------------------------------------------------------------------
sub init {
- my ($self, $config) = @_;
+ my ( $self, $config ) = @_;
- # ------------------------------------------------------------------
+ #
# Set the parser and producer.
#
# If a 'parser' or 'from' parameter is passed in, use that as the
# parser; if a 'producer' or 'to' parameter is passed in, use that
# as the producer; both default to $DEFAULT_SUB.
- # ------------------------------------------------------------------
- $self->parser( $config->{'parser'} || $config->{'from'} || $DEFAULT_SUB);
+ #
+ $self->parser ($config->{'parser'} || $config->{'from'} || $DEFAULT_SUB);
$self->producer($config->{'producer'} || $config->{'to'} || $DEFAULT_SUB);
- # ------------------------------------------------------------------
+ #
# Set the parser_args and producer_args
- # ------------------------------------------------------------------
- for my $pargs (qw(parser_args producer_args)) {
- $self->$pargs($config->{$pargs}) if defined $config->{$pargs};
+ #
+ for my $pargs ( qw[ parser_args producer_args ] ) {
+ $self->$pargs( $config->{$pargs} ) if defined $config->{ $pargs };
}
- # ------------------------------------------------------------------
+ #
# Set the data source, if 'filename' or 'file' is provided.
- # ------------------------------------------------------------------
+ #
$config->{'filename'} ||= $config->{'file'} || "";
- $self->filename($config->{'filename'}) if $config->{'filename'};
+ $self->filename( $config->{'filename'} ) if $config->{'filename'};
- # ------------------------------------------------------------------
- # Finally, if there is a 'data' parameter, use that in preference
- # to filename and file
- # ------------------------------------------------------------------
- if (my $data = $config->{'data'}) {
- $self->data($data);
+ #
+ # Finally, if there is a 'data' parameter, use that in
+ # preference to filename and file
+ #
+ if ( my $data = $config->{'data'} ) {
+ $self->data( $data );
}
- $self->{'debug'} = $DEBUG;
- $self->{'debug'} = $config->{'debug'} if (defined $config->{'debug'});
-
- return $self;
-}
-
-=head1 METHODS
-
-=head2 B<producer>
-
-The B<producer> method is an accessor/mutator, used to retrieve or
-define what subroutine is called to produce the output. A subroutine
-defined as a producer will be invoked as a function (not a method) and
-passed 2 parameters: its container SQL::Translator instance and a
-data structure. It is expected that the function transform the data
-structure to a string. The SQL::Transformer instance is provided for
-informational purposes; for example, the type of the parser can be
-retrieved using the B<parser_type> method, and the B<error> and
-B<debug> methods can be called when needed.
-
-When defining a producer, one of several things can be passed
-in: A module name (e.g., My::Groovy::Producer), a module name
-relative to the SQL::Translator::Producer namespace (e.g., MySQL), a
-module name and function combination (My::Groovy::Producer::transmogrify),
-or a reference to an anonymous subroutine. If a full module name is
-passed in (for the purposes of this method, a string containing "::"
-is considered to be a module name), it is treated as a package, and a
-function called "produce" will be invoked: $modulename::produce. If
-$modulename cannot be loaded, the final portion is stripped off and
-treated as a function. In other words, if there is no file named
-My/Groovy/Producer/transmogrify.pm, SQL::Translator will attempt to load
-My/Groovy/Producer.pm and use transmogrify as the name of the function,
-instead of the default "produce".
-
- my $tr = SQL::Translator->new;
-
- # This will invoke My::Groovy::Producer::produce($tr, $data)
- $tr->producer("My::Groovy::Producer");
+ #
+ # Set various other options.
+ #
+ $self->{'debug'} = defined $config->{'debug'} ? $config->{'debug'} : $DEBUG;
- # This will invoke SQL::Translator::Producer::Sybase::produce($tr, $data)
- $tr->producer("Sybase");
- # This will invoke My::Groovy::Producer::transmogrify($tr, $data),
- # assuming that My::Groovy::Producer::transmogrify is not a module
- # on disk.
- $tr->producer("My::Groovy::Producer::transmogrify");
+ $self->add_drop_table( $config->{'add_drop_table'} );
+
+ $self->custom_translate( $config->{'xlate'} );
- # This will invoke the referenced subroutine directly, as
- # $subref->($tr, $data);
- $tr->producer(\&my_producer);
+ $self->no_comments( $config->{'no_comments'} );
-There is also a method named B<producer_type>, which is a string
-containing the classname to which the above B<produce> function
-belongs. In the case of anonymous subroutines, this method returns
-the string "CODE".
+ $self->show_warnings( $config->{'show_warnings'} );
-Finally, there is a method named B<producer_args>, which is both an
-accessor and a mutator. Arbitrary data may be stored in name => value
-pairs for the producer subroutine to access:
+ $self->trace( $config->{'trace'} );
- sub My::Random::producer {
- my ($tr, $data) = @_;
- my $pr_args = $tr->producer_args();
+ return $self;
+}
- # $pr_args is a hashref.
+# ----------------------------------------------------------------------
+# add_drop_table([$bool])
+# ----------------------------------------------------------------------
+sub add_drop_table {
+ my $self = shift;
+ if ( defined (my $arg = shift) ) {
+ $self->{'add_drop_table'} = $arg ? 1 : 0;
+ }
+ return $self->{'add_drop_table'} || 0;
+}
-Extra data passed to the B<producer> method is passed to
-B<producer_args>:
- $tr->producer("xSV", delimiter => ',\s*');
+# ----------------------------------------------------------------------
+# custom_translate([$bool])
+# ----------------------------------------------------------------------
+sub custom_translate {
+ my $self = shift;
+ $self->{'custom_translate'} = shift if @_;
+ return $self->{'custom_translate'} || {};
+}
- # In SQL::Translator::Producer::xSV:
- my $args = $tr->producer_args;
- my $delimiter = $args->{'delimiter'}; # value is ,\s*
+# ----------------------------------------------------------------------
+# no_comments([$bool])
+# ----------------------------------------------------------------------
+sub no_comments {
+ my $self = shift;
+ my $arg = shift;
+ if ( defined $arg ) {
+ $self->{'no_comments'} = $arg ? 1 : 0;
+ }
+ return $self->{'no_comments'} || 0;
+}
-=cut
-# producer and producer_type
+# ----------------------------------------------------------------------
+# producer([$producer_spec])
+#
+# Get or set the producer for the current translator.
+# ----------------------------------------------------------------------
sub producer {
my $self = shift;
# get code reference and assign
$self->{'producer'} = \&{ "$producer\::$func_name" };
$self->{'producer_type'} = $producer;
- $self->debug("Got producer: $producer\::$func_name");
+ $self->debug("Got producer: $producer\::$func_name\n");
}
# passed an anonymous subroutine reference
elsif (isa($producer, 'CODE')) {
$self->{'producer'} = $producer;
$self->{'producer_type'} = "CODE";
- $self->debug("Got producer: code ref");
+ $self->debug("Got producer: code ref\n");
}
# passed a string containing no "::"; relative package name
load($Pp) or die "Can't load $Pp: $@";
$self->{'producer'} = \&{ "$Pp\::produce" };
$self->{'producer_type'} = $Pp;
- $self->debug("Got producer: $Pp");
+ $self->debug("Got producer: $Pp\n");
}
# At this point, $self->{'producer'} contains a subroutine
};
# ----------------------------------------------------------------------
-# producer_type
+# producer_type()
#
# producer_type is an accessor that allows producer subs to get
# information about their origin. This is poptentially important;
sub producer_type { $_[0]->{'producer_type'} }
# ----------------------------------------------------------------------
-# producer_args
+# producer_args([\%args])
#
# Arbitrary name => value pairs of paramters can be passed to a
# producer using this method.
+#
+# If the first argument passed in is undef, then the hash of arguments
+# is cleared; all subsequent elements are added to the hash of name,
+# value pairs stored as producer_args.
# ----------------------------------------------------------------------
sub producer_args {
my $self = shift;
- if (@_) {
- my $args = isa($_[0], 'HASH') ? shift : { @_ };
- $self->{'producer_args'} = $args;
- }
- $self->{'producer_args'};
+ return $self->_args("producer", @_);
}
-=head2 B<parser>
-
-The B<parser> method defines or retrieves a subroutine that will be
-called to perform the parsing. The basic idea is the same as that of
-B<producer> (see above), except the default subroutine name is
-"parse", and will be invoked as $module_name::parse($tr, $data).
-Also, the parser subroutine will be passed a string containing the
-entirety of the data to be parsed (or possibly a reference to a string?).
-
- # Invokes SQL::Translator::Parser::MySQL::parse()
- $tr->parser("MySQL");
-
- # Invokes My::Groovy::Parser::parse()
- $tr->parser("My::Groovy::Parser");
-
- # Invoke an anonymous subroutine directly
- $tr->parser(sub {
- my $dumper = Data::Dumper->new([ $_[1] ], [ "SQL" ]);
- $dumper->Purity(1)->Terse(1)->Deepcopy(1);
- return $dumper->Dump;
- });
-
-There is also B<parser_type> and B<parser_args>, which perform
-analogously to B<producer_type> and B<producer_args>
-=cut
+# ----------------------------------------------------------------------
+# parser([$parser_spec])
+# ----------------------------------------------------------------------
sub parser {
my $self = shift;
# get code reference and assign
$self->{'parser'} = \&{ "$parser\::$func_name" };
$self->{'parser_type'} = $parser;
- $self->debug("Got parser: $parser\::$func_name");
+ $self->debug("Got parser: $parser\::$func_name\n");
}
# passed an anonymous subroutine reference
- elsif (isa($parser, 'CODE')) {
- $self->{'parser'} = $parser;
+ elsif ( isa( $parser, 'CODE' ) ) {
+ $self->{'parser'} = $parser;
$self->{'parser_type'} = "CODE";
- $self->debug("Got parser: code ref");
+ $self->debug("Got parser: code ref\n");
}
# passed a string containing no "::"; relative package name
else {
- my $Pp = sprintf "SQL::Translator::Parser::$parser";
- load($Pp) or die "Can't load $Pp: $@";
- $self->{'parser'} = \&{ "$Pp\::parse" };
+ my $Pp = "SQL::Translator::Parser::$parser";
+ load( $Pp ) or die "Can't load $Pp: $@";
+ $self->{'parser'} = \&{ "$Pp\::parse" };
$self->{'parser_type'} = $Pp;
- $self->debug("Got parser: $Pp");
+ $self->debug("Got parser: $Pp\n");
}
+ #
# At this point, $self->{'parser'} contains a subroutine
# reference that is ready to run
-
- $self->parser_args(@_) if (@_);
+ #
+ $self->parser_args( @_ ) if (@_);
}
return $self->{'parser'};
}
+# ----------------------------------------------------------------------
sub parser_type { $_[0]->{'parser_type'} }
-# parser_args
sub parser_args {
my $self = shift;
- if (@_) {
- my $args = isa($_[0], 'HASH') ? shift : { @_ };
- $self->{'parser_args'} = $args;
- }
- $self->{'parser_args'};
-}
-
-=head2 B<translate>
-
-The B<translate> method calls the subroutines referenced by the
-B<parser> and B<producer> data members (described above). It accepts
-as arguments a number of things, in key => value format, including
-(potentially) a parser and a producer (they are passed directly to the
-B<parser> and B<producer> methods).
-
-Here is how the parameter list to B<translate> is parsed:
-
-=over
-
-=item *
-
-1 argument means it's the data to be parsed; which could be a string
-(filename) or a refernce to a scalar (a string stored in memory), or a
-reference to a hash, which is parsed as being more than one argument
-(see next section).
-
- # Parse the file /path/to/datafile
- my $output = $tr->translate("/path/to/datafile");
-
- # Parse the data contained in the string $data
- my $output = $tr->translate(\$data);
-
-=item *
-
-More than 1 argument means its a hash of things, and it might be
-setting a parser, producer, or datasource (this key is named
-"filename" or "file" if it's a file, or "data" for a SCALAR reference.
-
- # As above, parse /path/to/datafile, but with different producers
- for my $prod ("MySQL", "XML", "Sybase") {
- print $tr->translate(
- producer => $prod,
- filename => "/path/to/datafile",
- );
- }
-
- # The filename hash key could also be:
- datasource => \$data,
-
-You get the idea.
-
-=back
-
-=head2 B<filename>, B<data>
-
-Using the B<filename> method, the filename of the data to be parsed
-can be set. This method can be used in conjunction with the B<data>
-method, below. If both the B<filename> and B<data> methods are
-invoked as mutators, the data set in the B<data> method is used.
-
- $tr->filename("/my/data/files/create.sql");
-
-or:
-
- my $create_script = do {
- local $/;
- open CREATE, "/my/data/files/create.sql" or die $!;
- <CREATE>;
- };
- $tr->data(\$create_script);
+ return $self->_args("parser", @_);
+}
-B<filename> takes a string, which is interpreted as a filename.
-B<data> takes a reference to a string, which is used as the data to be
-parsed. If a filename is set, then that file is opened and read when
-the B<translate> method is called, as long as the data instance
-variable is not set.
+sub show_warnings {
+ my $self = shift;
+ my $arg = shift;
+ if ( defined $arg ) {
+ $self->{'show_warnings'} = $arg ? 1 : 0;
+ }
+ return $self->{'show_warnings'} || 0;
+}
-=cut
# filename - get or set the filename
sub filename {
return $self->error($msg);
} elsif (-f _ && -r _) {
$self->{'filename'} = $filename;
- $self->debug("Got filename: $self->{'filename'}");
+ $self->debug("Got filename: '$self->{'filename'}'\n");
} else {
my $msg = "Cannot use '$filename' as input source: ".
"file does not exist or is not readable.";
$self->{'filename'};
}
-# data - get or set the data
+# ----------------------------------------------------------------------
+# data([$data])
+#
# if $self->{'data'} is not set, but $self->{'filename'} is, then
-# $self->{'filename'} is opened and read, whith the results put into
+# $self->{'filename'} is opened and read, with the results put into
# $self->{'data'}.
+# ----------------------------------------------------------------------
sub data {
my $self = shift;
- # Set $self->{'data'} to $_[0], if it is provided.
+ # Set $self->{'data'} based on what was passed in. We will
+ # accept a number of things; do our best to get it right.
if (@_) {
my $data = shift;
if (isa($data, "SCALAR")) {
$self->{'data'} = $data;
}
- elsif (! ref $data) {
+ else {
+ if (isa($data, 'ARRAY')) {
+ $data = join '', @$data;
+ }
+ elsif (isa($data, 'GLOB')) {
+ local $/;
+ $data = <$data>;
+ }
+ elsif (! ref $data && @_) {
+ $data = join '', $data, @_;
+ }
$self->{'data'} = \$data;
}
}
# If we have a filename but no data yet, populate.
if (not $self->{'data'} and my $filename = $self->filename) {
- $self->debug("Opening '$filename' to get contents...");
+ $self->debug("Opening '$filename' to get contents.\n");
local *FH;
local $/;
my $data;
unless (open FH, $filename) {
- return $self->error("Can't open $filename for reading: $!");
+ return $self->error("Can't read file '$filename': $!");
}
$data = <FH>;
$self->{'data'} = \$data;
unless (close FH) {
- return $self->error("Can't close $filename: $!");
+ return $self->error("Can't close file '$filename': $!");
}
}
return $self->{'data'};
}
-# translate
-sub translate {
+
+sub trace {
my $self = shift;
- my ($args, $parser, $parser_type, $producer, $producer_type);
- my ($parser_output, $producer_output);
+ my $arg = shift;
+ if ( defined $arg ) {
+ $self->{'trace'} = $arg ? 1 : 0;
+ }
+ return $self->{'trace'} || 0;
+}
- # Parse arguments
+# ----------------------------------------------------------------------
+# translate([source], [\%args])
+#
+# translate does the actual translation. The main argument is the
+# source of the data to be translated, which can be a filename, scalar
+# reference, or glob reference.
+#
+# Alternatively, translate takes optional arguements, which are passed
+# to the appropriate places. Most notable of these arguments are
+# parser and producer, which can be used to set the parser and
+# producer, respectively. This is the applications last chance to set
+# these.
+#
+# translate returns a string.
+# ----------------------------------------------------------------------
+sub translate { my $self = shift; my ($args, $parser, $parser_type,
+$producer, $producer_type); my ($parser_output, $producer_output);
+
+ # Parse arguments
if (@_ == 1) {
# Passed a reference to a hash?
if (isa($_[0], 'HASH')) {
# yep, a hashref
- $self->debug("translate: Got a hashref");
+ $self->debug("translate: Got a hashref\n");
$args = $_[0];
}
+ # Passed a GLOB reference, i.e., filehandle
+ elsif (isa($_[0], 'GLOB')) {
+ $self->debug("translate: Got a GLOB reference\n");
+ $self->data($_[0]);
+ }
+
# Passed a reference to a string containing the data
elsif (isa($_[0], 'SCALAR')) {
# passed a ref to a string
- $self->debug("translate: Got a SCALAR reference (string)");
+ $self->debug("translate: Got a SCALAR reference (string)\n");
$self->data($_[0]);
}
# Not a reference; treat it as a filename
elsif (! ref $_[0]) {
# Not a ref, it's a filename
- $self->debug("translate: Got a filename");
+ $self->debug("translate: Got a filename\n");
$self->filename($_[0]);
}
return $producer_output;
}
+# ----------------------------------------------------------------------
+# list_parsers()
+#
+# Hacky sort of method to list all available parsers. This has
+# several problems:
+#
+# - Only finds things in the SQL::Translator::Parser namespace
+#
+# - Only finds things that are located in the same directory
+# as SQL::Translator::Parser. Yeck.
+#
+# This method will fail in several very likely cases:
+#
+# - Parser modules in different namespaces
+#
+# - Parser modules in the SQL::Translator::Parser namespace that
+# have any XS componenets will be installed in
+# arch_lib/SQL/Translator.
+#
+# ----------------------------------------------------------------------
+sub list_parsers {
+ return _list("parsers");
+}
+
+# ----------------------------------------------------------------------
+# list_producers()
+#
+# See notes for list_parsers(), above; all the problems apply to
+# list_producers as well.
+# ----------------------------------------------------------------------
+sub list_producers {
+ return _list("producers");
+}
+
+
+# ======================================================================
+# Private Methods
+# ======================================================================
+
+# ----------------------------------------------------------------------
+# _args($type, \%args);
+#
+# Gets or sets ${type}_args. Called by parser_args and producer_args.
+# ----------------------------------------------------------------------
+sub _args {
+ my $self = shift;
+ my $type = shift;
+ $type = "${type}_args" unless $type =~ /_args$/;
+
+ unless (defined $self->{$type} && isa($self->{$type}, 'HASH')) {
+ $self->{$type} = { };
+ }
+
+ if (@_) {
+ # If the first argument is an explicit undef (remember, we
+ # don't get here unless there is stuff in @_), then we clear
+ # out the producer_args hash.
+ if (! defined $_[0]) {
+ shift @_;
+ %{$self->{$type}} = ();
+ }
+
+ my $args = isa($_[0], 'HASH') ? shift : { @_ };
+ %{$self->{$type}} = (%{$self->{$type}}, %$args);
+ }
+
+ $self->{$type};
+}
+
+
+# ----------------------------------------------------------------------
+# _list($type)
+# ----------------------------------------------------------------------
+sub _list {
+ my $type = ucfirst lc $_[0] || return ();
+
+ load("SQL::Translator::$type");
+ my $path = catfile(dirname($INC{'SQL/Translator/$type.pm'}), $type);
+ my $dh = IO::Dir->new($path);
+
+ return map { join "::", "SQL::Translator::$type", $_ }
+ grep /\.pm$/, $dh->read;
+}
+
+# ----------------------------------------------------------------------
+# load($module)
+#
+# Loads a Perl module. Short circuits if a module is already loaded.
+# ----------------------------------------------------------------------
sub load {
my $module = do { my $m = shift; $m =~ s[::][/]g; "$m.pm" };
return 1 if $INC{$module};
return 1;
}
-sub isa { UNIVERSAL::isa($_[0], $_[1]) }
+# ----------------------------------------------------------------------
+# isa($ref, $type)
+#
+# Calls UNIVERSAL::isa($ref, $type). I think UNIVERSAL::isa is ugly,
+# but I like function overhead.
+# ----------------------------------------------------------------------
+sub isa($$) {
+ my ($ref, $type) = @_;
+ return UNIVERSAL::isa($ref, $type);
+}
1;
-
-__END__
#-----------------------------------------------------
# Rescue the drowning and tie your shoestrings.
# Henry David Thoreau
#-----------------------------------------------------
+__END__
+
+=head1 NAME
+
+SQL::Translator - convert schema from one database to another
+
+=head1 SYNOPSIS
+
+ use SQL::Translator;
+
+ my $translator = SQL::Translator->new(
+ xlate => $xlate || {}, # Overrides for field translation
+ debug => $debug, # Print debug info
+ trace => $trace, # Print Parse::RecDescent trace
+ no_comments => $no_comments, # Don't include comments in output
+ show_warnings => $show_warnings, # Print name mutations, conflicts
+ add_drop_table => $add_drop_table, # Add "drop table" statements
+ );
+
+ my $output = $translator->translate(
+ from => "MySQL",
+ to => "Oracle",
+ filename => $file,
+ ) or die $translator->error;
+
+ print $output;
+
+=head1 DESCRIPTION
+
+This module attempts to simplify the task of converting one database
+create syntax to another through the use of Parsers (which understand
+the source format) and Producers (which understand the destination
+format). The idea is that any Parser can be used with any Producer in
+the conversion process. So, if you wanted Postgres-to-Oracle, you
+would use the Postgres parser and the Oracle producer.
+
+=head1 CONSTRUCTOR
+
+The constructor is called B<new>, and accepts a optional hash of options.
+Valid options are:
+
+=over 4
+
+=item parser (aka from)
+
+=item parser_args
+
+=item producer (aka to)
+
+=item producer_args
+
+=item filename (aka file)
+
+=item data
+
+=item debug
+
+=back
+
+All options are, well, optional; these attributes can be set via
+instance methods. Internally, they are; no (non-syntactical)
+advantage is gained by passing options to the constructor.
+
+=head1 METHODS
+
+=head2 B<add_drop_table>
+
+Toggles whether or not to add "DROP TABLE" statements just before the
+create definitions.
+
+=head2 B<custom_translate>
+
+Allows the user to override default translation of fields. For example,
+if a MySQL "text" field would normally be converted to a "long" for Oracle,
+the user could specify to change it to a "CLOB." Accepts a hashref where
+keys are the "from" value and values are the "to," returns the current
+value of the field.
+
+=head2 B<no_comments>
+
+Toggles whether to print comments in the output. Accepts a true or false
+value, returns the current value.
+
+=head2 B<producer>
+
+The B<producer> method is an accessor/mutator, used to retrieve or
+define what subroutine is called to produce the output. A subroutine
+defined as a producer will be invoked as a function (I<not a method>)
+and passed 2 parameters: its container SQL::Translator instance and a
+data structure. It is expected that the function transform the data
+structure to a string. The SQL::Transformer instance is provided for
+informational purposes; for example, the type of the parser can be
+retrieved using the B<parser_type> method, and the B<error> and
+B<debug> methods can be called when needed.
+
+When defining a producer, one of several things can be passed
+in: A module name (e.g., My::Groovy::Producer), a module name
+relative to the SQL::Translator::Producer namespace (e.g., MySQL), a
+module name and function combination (My::Groovy::Producer::transmogrify),
+or a reference to an anonymous subroutine. If a full module name is
+passed in (for the purposes of this method, a string containing "::"
+is considered to be a module name), it is treated as a package, and a
+function called "produce" will be invoked: $modulename::produce. If
+$modulename cannot be loaded, the final portion is stripped off and
+treated as a function. In other words, if there is no file named
+My/Groovy/Producer/transmogrify.pm, SQL::Translator will attempt to load
+My/Groovy/Producer.pm and use transmogrify as the name of the function,
+instead of the default "produce".
+
+ my $tr = SQL::Translator->new;
+
+ # This will invoke My::Groovy::Producer::produce($tr, $data)
+ $tr->producer("My::Groovy::Producer");
+
+ # This will invoke SQL::Translator::Producer::Sybase::produce($tr, $data)
+ $tr->producer("Sybase");
+
+ # This will invoke My::Groovy::Producer::transmogrify($tr, $data),
+ # assuming that My::Groovy::Producer::transmogrify is not a module
+ # on disk.
+ $tr->producer("My::Groovy::Producer::transmogrify");
+
+ # This will invoke the referenced subroutine directly, as
+ # $subref->($tr, $data);
+ $tr->producer(\&my_producer);
+
+There is also a method named B<producer_type>, which is a string
+containing the classname to which the above B<produce> function
+belongs. In the case of anonymous subroutines, this method returns
+the string "CODE".
+
+Finally, there is a method named B<producer_args>, which is both an
+accessor and a mutator. Arbitrary data may be stored in name => value
+pairs for the producer subroutine to access:
+
+ sub My::Random::producer {
+ my ($tr, $data) = @_;
+ my $pr_args = $tr->producer_args();
+
+ # $pr_args is a hashref.
+
+Extra data passed to the B<producer> method is passed to
+B<producer_args>:
+
+ $tr->producer("xSV", delimiter => ',\s*');
+
+ # In SQL::Translator::Producer::xSV:
+ my $args = $tr->producer_args;
+ my $delimiter = $args->{'delimiter'}; # value is ,\s*
+
+=head2 B<parser>
+
+The B<parser> method defines or retrieves a subroutine that will be
+called to perform the parsing. The basic idea is the same as that of
+B<producer> (see above), except the default subroutine name is
+"parse", and will be invoked as $module_name::parse($tr, $data).
+Also, the parser subroutine will be passed a string containing the
+entirety of the data to be parsed.
+
+ # Invokes SQL::Translator::Parser::MySQL::parse()
+ $tr->parser("MySQL");
+
+ # Invokes My::Groovy::Parser::parse()
+ $tr->parser("My::Groovy::Parser");
+
+ # Invoke an anonymous subroutine directly
+ $tr->parser(sub {
+ my $dumper = Data::Dumper->new([ $_[1] ], [ "SQL" ]);
+ $dumper->Purity(1)->Terse(1)->Deepcopy(1);
+ return $dumper->Dump;
+ });
+
+There is also B<parser_type> and B<parser_args>, which perform
+analogously to B<producer_type> and B<producer_args>
+
+=head2 B<show_warnings>
+
+Toggles whether to print warnings of name conflicts, identifier
+mutations, etc. Probably only generated by producers to let the user
+know when something won't translate very smoothly (e.g., MySQL "enum"
+fields into Oracle). Accepts a true or false value, returns the
+current value.
+
+=head2 B<translate>
+
+The B<translate> method calls the subroutines referenced by the
+B<parser> and B<producer> data members (described above). It accepts
+as arguments a number of things, in key => value format, including
+(potentially) a parser and a producer (they are passed directly to the
+B<parser> and B<producer> methods).
+
+Here is how the parameter list to B<translate> is parsed:
+
+=over
+
+=item *
+
+1 argument means it's the data to be parsed; which could be a string
+(filename) or a refernce to a scalar (a string stored in memory), or a
+reference to a hash, which is parsed as being more than one argument
+(see next section).
+
+ # Parse the file /path/to/datafile
+ my $output = $tr->translate("/path/to/datafile");
+
+ # Parse the data contained in the string $data
+ my $output = $tr->translate(\$data);
+
+=item *
+
+More than 1 argument means its a hash of things, and it might be
+setting a parser, producer, or datasource (this key is named
+"filename" or "file" if it's a file, or "data" for a SCALAR reference.
+
+ # As above, parse /path/to/datafile, but with different producers
+ for my $prod ("MySQL", "XML", "Sybase") {
+ print $tr->translate(
+ producer => $prod,
+ filename => "/path/to/datafile",
+ );
+ }
+
+ # The filename hash key could also be:
+ datasource => \$data,
+
+You get the idea.
+
+=back
+
+=head2 B<filename>, B<data>
+
+Using the B<filename> method, the filename of the data to be parsed
+can be set. This method can be used in conjunction with the B<data>
+method, below. If both the B<filename> and B<data> methods are
+invoked as mutators, the data set in the B<data> method is used.
+
+ $tr->filename("/my/data/files/create.sql");
+
+or:
+
+ my $create_script = do {
+ local $/;
+ open CREATE, "/my/data/files/create.sql" or die $!;
+ <CREATE>;
+ };
+ $tr->data(\$create_script);
+
+B<filename> takes a string, which is interpreted as a filename.
+B<data> takes a reference to a string, which is used as the data to be
+parsed. If a filename is set, then that file is opened and read when
+the B<translate> method is called, as long as the data instance
+variable is not set.
+
+=pod
+
+=head2 B<trace>
+
+Turns on/off the tracing option of Parse::RecDescent.
+
+=pod
+
=head1 AUTHORS
-Ken Y. Clark, E<lt>kclark@logsoft.comE<gt>,
-darren chamberlain E<lt>darren@cpan.orgE<gt>
+Ken Y. Clark, E<lt>kclark@cpan.org<gt>,
+darren chamberlain E<lt>darren@cpan.orgE<gt>,
+Chris Mungall E<lt>cjm@fruitfly.orgE<gt>
=head1 COPYRIGHT
=head1 SEE ALSO
-L<perl>, L<Parse::RecDescent>
+L<perl>,
+L<SQL::Translator::Parser>,
+L<SQL::Translator::Producer>,
+L<Parse::RecDescent>
-=cut