Connecting two Repositories to the same DB table

questions
1

Hey, i’m writing app in Hanami 1.3 and have hard time trying to connect two repositories to the same table.

Is it doable in Hanami 1.3?

I dug a little bit and it looks to me that either rom in version 3 doesn’t support this, or it’s some missing feature in Hanami-model.
I tried to hack around, and managed to connect two Repository classes using the same relation (had to make some changes in ROM gem), but i still cannot make second repository to map data to different Entity.

Again, does anyone know if it is doable? :slight_smile:

2

@synu could you please share the relevant code and what error you see? Thanks.

3

@jodosha sure, here you go :slight_smile:

class DepositRepository < Hanami::Repository
end

module Imports
  class DepositRepository < Hanami::Repository
    self.relation = 'deposits'
  end
end

class Deposit < Hanami::Entity
end

module Imports
  class Deposit < Hanami::Entity
  end
end

Then i get error from ROM

Relation with `register_as :deposits` registered more than once

I managed to get rid of this issue by changing code in /home/pawel/.rvm/gems/ruby-2.7.2/gems/rom-3.3.3/lib/rom/setup/finalize/finalize_relations.rb

      def run!
        RelationRegistry.new do |registry, relations|
          @relation_classes.uniq! { |relation| relation.name } # <=== THIS IS THE LINE I ADDED
          @relation_classes.each do |klass|
            relation = build_relation(klass, registry)

            key = relation.name.to_sym

            if registry.key?(key)
              raise RelationAlreadyDefinedError,
                    "Relation with `register_as #{key.inspect}` registered more " \
                    "than once"
            end
            ...

But then, when i call Imports::DepositRepository.new.last i get instance of Deposit entity, and for now i failed to make it Imports::Deposit.

4

i dig a little and i think it’s missing functionality in Hanami-model.
From what i found out, i guess there are two missing pieces for this to work:

  1. We call configuration.relation(relation) in Hanami::Repository##define_relation which is delegated to ROM and which registers Relation class for given relation, and it is not checking if this relation was already registered
  2. We register mappings in Hanami::Repository##define_mapping with relation as a key and this doesn’t allow us to have different Entity mapping for the same relation

So, i think for now it’s simply impossible to do that :frowning:

5

for the record - i managed to connect hanami 1.3 with ROM 5.2, it’s doable, it works, only thing is due to some dependencies i also had to upgrade hanami-validations to 2.0.0.alpha :slight_smile: