Object.pm

# -*- Mode: perl; indent-tabs-mode: nil -*-
#
# The contents of this file are subject to the Mozilla Public
# License Version 1.1 (the "License"); you may not use this file
# except in compliance with the License. You may obtain a copy of
# the License at http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS
# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
# implied. See the License for the specific language governing
# rights and limitations under the License.
#
# The Original Code is the Bugzilla Bug Tracking System.
#
# Contributor(s): Max Kanat-Alexander <mkanat@bugzilla.org>

use strict;

package Bugzilla::Object;

use Bugzilla::Util;
use Bugzilla::Error;

use constant LIST_ORDER => 'name';

###############################
####    Initialization     ####
###############################

sub new {
    my $invocant = shift;
    my $class    = ref($invocant) || $invocant;
    my $object   = $class->_init(@_);
    bless($object, $class) if $object;
    return $object;
}

sub _init {
    my $class = shift;
    my ($param) = @_;
    my $dbh = Bugzilla->dbh;
    my $columns = join(',', $class->DB_COLUMNS);
    my $table   = $class->DB_TABLE;

    my $id = $param unless (ref $param eq 'HASH');
    my $object;

    if (defined $id) {
        detaint_natural($id)
          || ThrowCodeError('param_must_be_numeric',
                            {function => $class . '::_init'});

        $object = $dbh->selectrow_hashref(qq{
            SELECT $columns FROM $table
             WHERE id = ?}, undef, $id);
    } elsif (defined $param->{'name'}) {
        trick_taint($param->{'name'});
        $object = $dbh->selectrow_hashref(qq{
            SELECT $columns FROM $table
             WHERE name = ?}, undef, $param->{'name'});
    } else {
        ThrowCodeError('bad_arg',
            {argument => 'param',
             function => $class . '::_init'});
    }

    return $object;
}

sub new_from_list {
    my $class = shift;
    my ($id_list) = @_;
    my $dbh = Bugzilla->dbh;
    my $columns = join(',', $class->DB_COLUMNS);
    my $table   = $class->DB_TABLE;
    my $order   = $class->LIST_ORDER;

    my $objects;
    if (@$id_list) {
        my @detainted_ids;
        foreach my $id (@$id_list) {
            detaint_natural($id) ||
                ThrowCodeError('param_must_be_numeric',
                              {function => $class . '::new_from_list'});
            push(@detainted_ids, $id);
        }
        $objects = $dbh->selectall_arrayref(
            "SELECT $columns FROM $table WHERE id IN (" 
            . join(',', @detainted_ids) . ") ORDER BY $order", {Slice=>{}});
    } else {
        return [];
    }

    foreach my $object (@$objects) {
        bless($object, $class);
    }
    return $objects;
}

###############################
####      Accessors      ######
###############################

sub id                { return $_[0]->{'id'};          }
sub name              { return $_[0]->{'name'};        }

###############################
####      Subroutines    ######
###############################

sub get_all {
    my $class = shift;
    my $dbh = Bugzilla->dbh;
    my $table = $class->DB_TABLE;
    my $order = $class->LIST_ORDER;

    my $ids = $dbh->selectcol_arrayref(qq{
        SELECT id FROM $table ORDER BY $order});

    my $objects = $class->new_from_list($ids);
    return @$objects;
}

1;

__END__

=head1 NAME

Bugzilla::Object - A base class for objects in Bugzilla.

=head1 SYNOPSIS

 my $object = new Bugzilla::Object(1);
 my $object = new Bugzilla::Object({name => 'TestProduct'});

 my $id          = $object->id;
 my $name        = $object->name;

=head1 DESCRIPTION

Bugzilla::Object is a base class for Bugzilla objects. You never actually
create a Bugzilla::Object directly, you only make subclasses of it.

Basically, Bugzilla::Object exists to allow developers to create objects
more easily. All you have to do is define C<DB_TABLE>, C<DB_COLUMNS>,
and sometimes C<LIST_ORDER> and you have a whole new object.

You should also define accessors for any columns other than C<name>
or C<id>.

=head1 CONSTANTS

Frequently, these will be the only things you have to define in your
subclass in order to have a fully-functioning object. C<DB_TABLE>
and C<DB_COLUMNS> are required.

=over

=item C<DB_TABLE>

The name of the table that these objects are stored in. For example,
for C<Bugzilla::Keyword> this would be C<keyworddefs>.

=item C<DB_COLUMNS>

The names of the columns that you want to read out of the database
and into this object. This should be an array.

=item C<LIST_ORDER>

The order that C<new_from_list> and C<get_all> should return objects
in. This should be the name of a database column. Defaults to
C<name>.

=back

=head1 METHODS

=over

=item C<new($param)>

 Description: The constructor is used to load an existing object
              from the database, by id or by name.

 Params:      $param - If you pass an integer, the integer is the
                       id of the object, from the database, that we 
                       want to read in. If you pass in a hash with 
                       C<name> key, then the value of the name key 
                       is the name of the object from the DB.

 Returns:     A fully-initialized object.

=item C<new_from_list(\@id_list)>

 Description: Creates an array of objects, given an array of ids.

 Params:      \@id_list - A reference to an array of numbers, database ids.
                          If any of these are not numeric, the function
                          will throw an error. If any of these are not
                          valid ids in the database, they will simply 
                          be skipped.

 Returns:     A reference to an array of objects.

=back

=head1 SUBROUTINES

=over

=item C<get_all>

 Description: Returns all objects in this table from the database.

 Params:      none.

 Returns:     A list of objects, or an empty list if there are none.

 Notes:       Note that you must call this as C<$class->get_all>. For 
              example, C<Bugzilla::Keyword->get_all>. 
              C<Bugzilla::Keyword::get_all> will not work.

=back

=cut