File Coverage

blib/lib/Mandel/Relationship/ListOf.pm

Criterion	Covered	Total	%
statement	27	111	24.3
branch	0	50	0.0
condition	0	20	0.0
subroutine	8	22	36.3
pod	1	1	100.0
total	36	204	17.6

package Mandel::Relationship::ListOf;

=head1 NAME

Mandel::Relationship::ListOf - A field points to many other MongoDB documents

=head1 DESCRIPTION

L is a class used to describe the relationship
where one document has a list of DBRefs that point to other documents.
The connection between the documents is described in the database using
L.

This relationship is EXPERIMENTAL. Let me of you are using it or don't like it.

=head1 DATABASE STRUCTURE

A "person" that has I "cats" will look like this in the database:

  mongodb> db.persons.find();
  {
    "_id" : ObjectId("5353ab13800fac3a0a8d5049"),
    "kittens" : [
      DBRef("cats", ObjectId("5353ab13c5483e16a1010000")),
      DBRef("cats", ObjectId("5353ab13c5483e16a1020000"))
    ]
  }

  mongodb> db.cats.find();
  { "_id" : ObjectId("5353ab13c5483e16a1010000") }
  { "_id" : ObjectId("5353ab13c5483e16a1020000") }

=head1 SYNOPSIS

=head2 Using DSL

  package MyModel::Person;
  use Mandel::Document;
  list_of cats => 'MyModel::Cat';

=head2 Using object oriented interface

  MyModel::Person->model->relationship(
    "list_of",
    "cats",
    "MyModel::Cat",
  );

See also L.

=head2 Methods generated

  # non-blocking
  $person = MyModel::Person->new->push_cats($bson_oid, $pos, sub {
              my($person, $err, $cat_obj) = @_;
              # Note! This $cat_obj has only "id()" set
              # ...
            });

Add the C<$bson_oid> to the "cats" list in C<$person>.

  $person = MyModel::Person->new->push_cats(\%constructor_args, $pos, sub {
              my($person, $err, $cat_obj) = @_;
              # ...
            });

Pushing a new cat with C<%constructor_args> will also insert a new cat object
into the database.

  $person = MyModel::Person->new->push_cats($cat_obj, $pos, sub {
              my($person, $err, $cat_obj) = @_;
              # ...
            });

C<$pos> is optional. When omitted, C will add the new element
to the end of list. See
L
for details.

  $person = MyModel::Cat->new->remove_cats($bson_oid, sub {
              my($self, $err) = @_;
              # Note! This $cat_obj has only "id()" set
            });

  $person = MyModel::Cat->new->remove_cats($cat_obj, sub {
              my($self, $err) = @_;
              # ...
            });

Calling C will only remove the link, and not the related
object.

  $person = MyModel::Cat->new->cats(sub {
              my($self, $err, $array_of_cats) = @_;
              # ...
            });

Retrieve all the related cat objects.

  # blocking
  $cat_obj = MyModel::Person->new->push_cats($bson_oid);
  $cat_obj = MyModel::Person->new->push_cats(\%args);
  $cat_obj = MyModel::Person->new->push_cats($cat_obj);
  $person = MyModel::Person->new->remove_cats($bson_oid);
  $person = MyModel::Person->new->remove_cats($cat_obj);
  $array_of_cats = MyModel::Person->new->cats;

  $cat_collection = MyModel::Person->new->search_cats;

Note! C does not guaranty the order of the results, like C
does.

=cut

use Mojo::Base 'Mandel::Relationship';
use Mojo::Util;
use Mango::BSON 'bson_dbref';

=head1 ATTRIBUTES

L inherits all attributes from
L and implements the following new ones.

=head2 push_method_name

The name of the method used to add another document to the relationship.

=head2 remove_method_name

The name of the method used to remove an item from the list.

=head2 search_method_name

The name of the method used to search related documents.

=cut

has push_method_name   => sub { sprintf 'push_%s',   shift->accessor };
has remove_method_name => sub { sprintf 'remove_%s', shift->accessor };
has search_method_name => sub { sprintf 'search_%s', shift->accessor };

=head1 METHODS

L inherits all methods from
L and implements the following new ones.

=head2 monkey_patch

Add methods to L.

=cut

sub monkey_patch {
  shift->_monkey_patch_all_method->_monkey_patch_push_method->_monkey_patch_remove_method->_monkey_patch_search_method;
}

sub _monkey_patch_all_method {
  my $self     = shift;
  my $accessor = $self->accessor;
  my $search   = $self->search_method_name;

  Mojo::Util::monkey_patch(
    $self->document_class,
    $accessor,
    sub {
      my ($doc, $cb) = @_;
      my $cached = delete $doc->{fresh} ? undef : $doc->_cache($accessor);

      # Blocking
      unless ($cb) {
        return $cached if $cached;
        my %lookup = map { $_->id, $_ } @{$doc->$search->all};
        return $doc->_cache($accessor => [map { $lookup{$_->{'$id'}} } @{$doc->data->{$accessor} || []}]);
      }

      # Non-blocking
      if ($cached) {
        $doc->$cb('', $cached);
      }
      else {
        $doc->$search->all(
          sub {
            my ($collection, $err, $objs) = @_;
            my %lookup = map { $_->id, $_ } @$objs;
            $doc->$cb($err, $doc->_cache($accessor => [map { $lookup{$_->{'$id'}} } @{$doc->data->{$accessor} || []}]));
          }
        );
      }

      return $doc;
    }
  );

  return $self;
}

sub _monkey_patch_push_method {
  my $self     = shift;
  my $accessor = $self->accessor;

  Mojo::Util::monkey_patch(
    $self->document_class,
    $self->push_method_name,
    sub {
      my $cb = ref $_[-1] eq 'CODE' ? pop : undef;
      my ($doc, $obj, $pos) = @_;
      my ($dbref, $push_ref, @update);
      my $cached = $doc->_cache($accessor);

      if (ref $obj eq 'HASH') {
        $obj = $self->_related_model->new_collection($doc->connection)->create($obj);
      }
      elsif (UNIVERSAL::isa($obj, 'Mango::BSON::ObjectID')) {
        $obj = $self->_related_model->new_collection($doc->connection)->create({id => $obj});
        $obj->_mark_stored_clean;    # prevent save() from actually doing something below
      }

      $dbref = bson_dbref $obj->model->collection_name, $obj->id;

      @update = (
        {_id     => $doc->id},
        {'$push' => {$accessor => {'$each' => [$dbref], defined $pos ? ('$position' => $pos + 0) : ()}}},
        {upsert  => 1},
      );

      $push_ref = sub {
        my $list = $doc->data->{$accessor} ||= [];

        if (defined $pos and $pos < @$list) {
          splice @$cached, $pos, 0, $obj if $cached;
          splice @$list, $pos, 0, $dbref;
        }
        else {
          push @$cached, $obj if $cached;
          push @$list, $dbref;
        }

        $doc->in_storage(1);
      };

      # Blocking
      unless ($cb) {
        $obj->save;
        $doc->_storage_collection->update(@update);
        $push_ref->();
        return $obj;
      }

      # Non-blocking
      Mojo::IOLoop->delay(
        sub {
          my ($delay) = @_;
          $obj->save($delay->begin);
          $doc->_storage_collection->update(@update, $delay->begin);
        },
        sub {
          my ($delay, $o_err, $d_err, $updated) = @_;
          my $err = $o_err || $d_err;
          $err ||= 'Document was not stored. Unknown error' unless $updated and $updated->{n};
          $push_ref->() unless $err;
          $doc->$cb($err // '', $obj);
        },
      );

      return $doc;
    }
  );

  return $self;
}

sub _monkey_patch_remove_method {
  my $self     = shift;
  my $accessor = $self->accessor;

  Mojo::Util::monkey_patch(
    $self->document_class,
    $self->remove_method_name,
    sub {
      my ($doc, $obj, $cb) = @_;
      my $cached = $doc->_cache($accessor);
      my @update;

      unless (UNIVERSAL::isa($obj, 'Mandel::Document')) {
        $obj = $self->_related_model->new_collection($doc->connection)->create({_id => $obj});
      }

      @update = ({_id => $doc->id}, {'$pull' => {$accessor => bson_dbref($obj->model->collection_name, $obj->id)}});

      # Blocking
      unless ($cb) {
        $doc->_storage_collection->update(@update);
        $doc->data->{$accessor} = [grep { $_->{'$id'} ne $obj->id } @{$doc->data->{$accessor} || []}];
        @$cached = grep { $_->id ne $obj->id } @$cached if $cached;
        return $doc;
      }

      # Non-blocking
      Mojo::IOLoop->delay(
        sub {
          my ($delay) = @_;
          $doc->_storage_collection->update(@update, $delay->begin);
        },
        sub {
          my ($delay, $err, $updated) = @_;
          $doc->data->{$accessor} = [grep { $_->{'$id'} ne $obj->id } @{$doc->data->{$accessor} || []}] unless $err;
          @$cached = grep { $_->id ne $obj->id } @$cached if $cached and !$err;
          $doc->$cb($err);
        },
      );

      return $obj;
    }
  );

  return $self;
}

sub _monkey_patch_search_method {
  my $self     = shift;
  my $accessor = $self->accessor;

  Mojo::Util::monkey_patch(
    $self->document_class,
    $self->search_method_name,
    sub {
      my ($doc, $query, $extra) = @_;
      my $related_model = $self->_related_model;

      return $related_model->new_collection(
        $doc->connection,
        extra => $extra || {},
        query => {%{$query || {}}, _id => {'$in' => [map { $_->{'$id'} } @{$doc->data->{$accessor} || []}]}},
      );
    }
  );

  return $self;
}

=head1 SEE ALSO

L, L, L

=head1 AUTHOR

Jan Henning Thorsen - C

=cut

1;