[Dbix-class] $self->related_resultset( 'user_role' ) returning App::DB::ResultSet

[Bill Moseley]

Ok, I have an explanation.

We did a release and App::DB::ResultSet::UserRole is a new class.   But, we
cache User objects in Memcached (as a DBIC row).

And the old code did this:

    $user->search_related( 'user_role', { ... } );

which then populated $user->{related_resultsets}{user_role} with the
(default?) App::DB::Result class instance (and saved it in Memcached).

So, when we rolled out the new code it was using cached $user objects so
$user->{related_resultsets}{user_role} was the base ResultSet object which
didn't have the "my_method" method.

So, it may be as simple as delete $user->{related_resultsets} after
fetching the $user object from cache.   Can't be that expensive to look up
the relationships.

Or we could be disruptive and blow away the cache at release time.   But,
it's not a problem that happens very often.


I wonder if it makes sense for DBIC to not save related_resultset in
objects if there isn't a specific one -- which would have prevented this.
Seems like quite an edge-case.



On Wed, Jul 15, 2015 at 4:45 PM, Bill Moseley <moseley at hank.org> wrote:

>
>
> On Wed, Jul 15, 2015 at 3:15 PM, Francisco Obispo <francisco at obispo.link>
> wrote:
>
>> The result of
>>
>> $self->related_resultset( 'user_role' )
>>
>> is a App::DB::ResultSet
>>
>
> But it should return an App::DB::ResultSet::UserRole object.  "my_method"
> is in the App::DB::ResultSet::UserRole class.
>
> return $self->related_resultset( 'user_role' )->my_method->count > 0;
>
>
> When I printed Dumper $self->{related_resultsets} (in the
> related_resultset() method) when it was NOT working I was getting:
>
> *Note the class:*
>
>           'user_role' => bless( {
>                                   'pager' => undef,
>                                   'attrs' => {
>                                                'is_depends_on' => 0,
>                                                'cascade_copy' => 0,
>                                                'accessor' => 'multi',
>                                                'alias' => 'me',
>                                                'bind' =>
> 'ARRAY(0x7fdf9ac59198)',
>                                                'join_type' => 'LEFT',
>                                                'where' =>
> 'HASH(0x7fdf9ac58fd0)',
>                                                'cascade_delete' => 0
>                                              },
>                                   'cond' =>
> $VAR1->{'user_role'}{'attrs'}{'where'},
>                                   '_result_class' =>
> 'App::DB::Result::UserRole',
>                                   'result_source' => bless( {
>                                                               '_columns'
> => 'HASH(0x7fdf85857f40)',
>                                                               'schema' =>
> $VAR1->{'user_pref'}{'result_source'}{'schema'},
>
> '_unique_constraints' => 'HASH(0x7fdf9696ffc8)',
>
> '_relationships' => 'HASH(0x7fdf8585b0f8)',
>
> 'result_class' => 'Appi::DB::Result::UserRole',
>
> 'source_name' => 'UserRole',
>
> 'resultset_class' => 'App::DB::ResultSet::UserRole',
>
> '_columns_info_loaded' => 0,
>
> 'resultset_attributes' => 'HASH(0x7fdf85857a48)',
>                                                               '_primaries'
> => 'ARRAY(0x7fdf93dcb030)',
>
> '_ordered_columns' => 'ARRAY(0x7fdf858417e8)',
>                                                               'name' =>
> 'user_role'
>                                                             },
> 'DBIx::Class::ResultSource::Table' )
>                                 }, '*App::DB::ResultSet*' )
>
>
>
> And then when it is working correctly the Dump shows this:
>
>           'user_role' => bless( {
>                                   'result_source' => bless( {
>
> 'source_name' => 'UserRole',
>                                                               'name' =>
> 'user_role',
>
> '_columns_info_loaded' => 0,
>                                                               '_primaries'
> => 'ARRAY(0x4ceaea0)',
>                                                               'schema' =>
> 'App::DB=HASH(0x2c458d0)',
>
> 'result_class' => 'App::DB::Result::UserRole',
>
> '_relationships' => 'HASH(0x783f628)',
>
> 'resultset_attributes' => 'HASH(0x7834010)',
>
> 'resultset_class' => 'App::DB::ResultSet::UserRole',
>
> '_ordered_columns' => 'ARRAY(0x7825410)',
>                                                               '_columns'
> => 'HASH(0x7837d20)',
>
> '_unique_constraints' => 'HASH(0x4d17b40)'
>                                                             },
> 'DBIx::Class::ResultSource::Table' ),
>                                   'attrs' => {
>                                                'bind' =>
> 'ARRAY(0x7b1ace0)',
>                                                'cascade_delete' => 0,
>                                                'accessor' => 'multi',
>                                                'cascade_copy' => 0,
>                                                'is_depends_on' => 0,
>                                                'alias' => 'me',
>                                                'where' =>
> 'HASH(0x7b71fe0)',
>                                                'join_type' => 'LEFT'
>                                              },
>                                   'pager' => undef,
>                                   '_result_class' =>
> 'App::DB::Result::UserRole',
>                                   'cond' =>
> $VAR1->{'user_role'}{'attrs'}{'where'}
>                                 }, '*App::DB::ResultSet::UserRole*' )
>         };
>
> --
> Bill Moseley
> moseley at hank.org
>



-- 
Bill Moseley
moseley at hank.org
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