[Dbix-class] Passing values to a custom join condition

[Peter Rabbitson]

On Sun, Jan 05, 2014 at 09:44:13PM +0000, Andrew Beverley wrote:
> I'm using add_relationship to create a custom join condition, as
> described at
> https://metacpan.org/pod/DBIx::Class::Relationship::Base#condition
> 
> In a similar vein to the example in the manual, I have created the
> following relationship:
> 
> __PACKAGE__->has_many(
>   "site_single_tasks",
>   "Lenio::Schema::Result::SiteTask",
>   sub {
>       my $args = shift;
>       return {
>         "$args->{foreign_alias}.task_id" =>
>             { -ident => "$args->{self_alias}.id" },
>         "$args->{foreign_alias}.site_id" =>
>             { '=', "100" },
>       };
>   },
>   { cascade_copy => 0, cascade_delete => 0 },
> );
> 
> My question: is it possible for the value "100" in my code above to be a
> variable, with the value passed from ->search (or otherwise). I can't
> see anything in the args that are passed to the function that could be
> used.
> 
> The reason I'd like to do this, is that in my join I only want certain
> values from the table being joined; I want the missing ones to have a
> value of NULL, which would not be possible with a simple WHERE
> condition.
> 

Sorry for the late reply. The current recommended way to do this is to 
have the coderef in question refer to a global variable (and throw if 
the variable has not been local()-set to something before the search() 
condition is executed).

The long term solution hinges on this being implemented: 
http://lists.scsys.co.uk/pipermail/dbix-class/2014-January/011565.html

Cheers!