Feature: Display additional fields when attaching a record to another

app/controllers/avo/associations_controller.rb

@@ -12,6 +12,7 @@ class AssociationsController < BaseController
     before_action :set_attachment_class, only: [:show, :index, :new, :create, :destroy]
     before_action :set_attachment_resource, only: [:show, :index, :new, :create, :destroy]
     before_action :set_attachment_record, only: [:create, :destroy]
+    before_action :set_extra_fields, only: [:new, :create]
     before_action :authorize_index_action, only: :index
     before_action :authorize_attach_action, only: :new
     before_action :authorize_detach_action, only: :destroy
@@ -67,6 +68,7 @@ def create
               notice: t("avo.attachment_class_attached", attachment_class: @related_resource.name)
           }
         else
+          flash[:error] = t("avo.attachment_failed", attachment_class: @related_resource.name)
           format.turbo_stream {
             render turbo_stream: turbo_stream.append("alerts", partial: "avo/partials/all_alerts")
           }
@@ -78,7 +80,13 @@ def create_association
       association_name = BaseResource.valid_association_name(@record, association_from_params)
 
       perform_action_and_record_errors do
-        if has_many_reflection?
+        if through_reflection?
+          if additional_params?
+            new_join_record.save
+          else
+            @record.send(association_name) << @attachment_record
+          end
+        elsif has_many_reflection?
           @record.send(association_name) << @attachment_record
         else
           @record.send(:"#{association_name}=", @attachment_record)
@@ -194,5 +202,40 @@ def has_many_reflection?
         ActiveRecord::Reflection::HasAndBelongsToManyReflection
       ]
     end
+
+    def through_reflection?
+      reflection.instance_of? ActiveRecord::Reflection::ThroughReflection
+    end
+
+    def additional_params?
+      additional_params.keys.count >= 1
+    end
+
+    def additional_params
+      params[:fields].except("related_id")
+    end
+
+    def set_extra_fields
+      @extra = if @field.extra.present?
+        Avo::FieldsExecutionContext.new(target: @field.extra, parent: @record)
+          .detect_fields
+          .items_holder
+          .items
+      end
+    end
+
+    def new_join_record
+      field_names = Avo::FieldsExecutionContext.new(target: @field.extra, parent: @resource)
+        .detect_fields
+        .items
+        .map { |field| field.name.tr(" ", "_").downcase }
+
+      @resource.fill_join_record(
+        record: reflection.through_reflection.klass.new,
+        fields: @extra,
+        params: additional_params.permit(field_names).merge({source_foreign_key => @attachment_record.id, through_foreign_key => @record.id}),
+        extra_params: [source_foreign_key, through_foreign_key]
+      )
+    end
   end
 end

app/views/avo/associations/new.html.erb

@@ -41,6 +41,9 @@
                 class: input_classes('w-full'),
               }
             %>
+          <% @extra&.each_with_index do |ex, index| %>
+            <%= render(Avo::Items::SwitcherComponent.new(resource: @related_resource, item: ex, index: index + 1, view: @view, form: form, field_component_extra_args: {stacked: true})) %>
+          <% end %>
           </div>
         <% end %>
       </div>

lib/avo/fields/has_base_field.rb

@@ -13,6 +13,7 @@ class HasBaseField < BaseField
       attr_accessor :discreet_pagination
       attr_accessor :hide_search_input
       attr_reader :link_to_child_resource
+      attr_reader :extra
 
       def initialize(id, **args, &block)
         super(id, **args, &block)
@@ -27,6 +28,7 @@ def initialize(id, **args, &block)
         @link_to_child_resource = args[:link_to_child_resource] || false
         @reloadable = args[:reloadable].present? ? args[:reloadable] : false
         @linkable = args[:linkable].present? ? args[:linkable] : false
+        @extra = args[:extra].present? ? args[:extra] : nil
       end
 
       def field_resource

lib/avo/fields_execution_context.rb

@@ -0,0 +1,13 @@
+module Avo
+  class FieldsExecutionContext < Avo::ExecutionContext
+    include Avo::Concerns::HasItems
+
+    def detect_fields
+      self.items_holder = Avo::Resources::Items::Holder.new(parent: self)
+
+      instance_exec(&target) if target.present? && target.respond_to?(:call)
+
+      self
+    end
+  end
+end

lib/avo/resources/base.rb

@@ -285,14 +285,16 @@ def detect_fields
         self
       end
 
-      VIEW_METHODS_MAPPING = {
-        index: [:index_fields, :display_fields],
-        show: [:show_fields, :display_fields],
-        edit: [:edit_fields, :form_fields],
-        update: [:edit_fields, :form_fields],
-        new: [:new_fields, :form_fields],
-        create: [:new_fields, :form_fields]
-      } unless defined? VIEW_METHODS_MAPPING
+      unless defined? VIEW_METHODS_MAPPING
+        VIEW_METHODS_MAPPING = {
+          index: [:index_fields, :display_fields],
+          show: [:show_fields, :display_fields],
+          edit: [:edit_fields, :form_fields],
+          update: [:edit_fields, :form_fields],
+          new: [:new_fields, :form_fields],
+          create: [:new_fields, :form_fields]
+        }
+      end
 
       def fetch_fields
         possible_methods_for_view = VIEW_METHODS_MAPPING[view.to_sym]
@@ -334,12 +336,12 @@ def divider(label = nil)
         end
 
         # def get_actions / def get_filters / def get_scopes
-        define_method "get_#{plural_entity}" do
+        define_method :"get_#{plural_entity}" do
           return entity_loader(entity).bag if entity_loader(entity).present?
 
           # ex: @actions_loader = Avo::Loaders::ActionsLoader.new
           instance_variable_set(
-            "@#{plural_entity}_loader",
+            :"@#{plural_entity}_loader",
             "Avo::Loaders::#{plural_entity.humanize}Loader".constantize.new
           )
 
@@ -349,8 +351,8 @@ def divider(label = nil)
         end
 
         # def get_action_arguments / def get_filter_arguments / def get_scope_arguments
-        define_method "get_#{entity}_arguments" do |entity_class|
-          klass = send("get_#{plural_entity}").find { |entity| entity[:class].to_s == entity_class.to_s }
+        define_method :"get_#{entity}_arguments" do |entity_class|
+          klass = send(:"get_#{plural_entity}").find { |entity| entity[:class].to_s == entity_class.to_s }
 
           raise "Couldn't find '#{entity_class}' in the 'def #{plural_entity}' method on your '#{self.class}' resource." if klass.nil?
 
@@ -359,7 +361,7 @@ def divider(label = nil)
       end
 
       def hydrate(...)
-        super(...)
+        super
 
         if @record.present?
           hydrate_model_with_default_values if @view&.new?
@@ -395,7 +397,7 @@ def record_title
         return name if @record.nil?
 
         # Get the title from the record if title is not set, try to get the name, title or label, or fallback to the id
-        return @record.try(:name) || @record.try(:title) || @record.try(:label) || @record.id  if title.nil?
+        return @record.try(:name) || @record.try(:title) || @record.try(:label) || @record.id if title.nil?
 
         # If the title is a symbol, get the value from the record else execute the block/string
         case title
@@ -462,6 +464,25 @@ def fill_record(record, params, extra_params: [])
         record
       end
 
+      def fill_join_record(record:, fields:, params:, extra_params:)
+        # Write the field values
+        params.each do |key, value|
+          field = fields.find { |f| f.id == key.to_sym }
+
+          next unless field.present?
+
+          record = field.fill_field record, key, value, params
+        end
+
+        # Write the user configured extra params to the record
+        if extra_params.present?
+          # Let Rails fill in the rest of the params
+          record.assign_attributes params.permit(extra_params)
+        end
+
+        record
+      end
+
       def authorization(user: nil)
         current_user = user || Avo::Current.user
         Avo::Services::AuthorizationService.new(current_user, record || model_class, policy_class: authorization_policy)
@@ -601,7 +622,7 @@ def description_attributes
       end
 
       def entity_loader(entity)
-        instance_variable_get("@#{entity.to_s.pluralize}_loader")
+        instance_variable_get(:"@#{entity.to_s.pluralize}_loader")
       end
     end
   end

spec/dummy/app/avo/resources/store.rb

@@ -11,5 +11,16 @@ def fields
       # Example for error message when resource is missing
       field :location, as: :has_one
     end
+
+    field :patrons, as: :has_many, through: :patronships,
+      translation_key: "patrons",
+      extra: -> {
+        if ENV["TEST_FILL_JOIN_RECORD"]
+          field :review, as: :text,
+            update_using: -> { ">> #{value} <<" }
+        else
+          field :review, as: :text
+        end
+      }
   end
 end

spec/dummy/app/models/store.rb

@@ -10,4 +10,7 @@
 #
 class Store < ApplicationRecord
   has_one :location
+
+  has_many :patronships, class_name: :StorePatron
+  has_many :patrons, through: :patronships, class_name: :User, source: :user
 end

spec/dummy/app/models/store_patron.rb

@@ -0,0 +1,6 @@
+class StorePatron < ApplicationRecord
+  belongs_to :store
+  belongs_to :user
+
+  validates :review, presence: true
+end

spec/dummy/config/locales/avo.en.yml

@@ -16,6 +16,7 @@ en:
     attach_item: Attach %{item}
     attachment_class_attached: "%{attachment_class} attached."
     attachment_class_detached: "%{attachment_class} detached."
+    attachment_failed: "Failed to attach %{attachment_class}"
     attachment_destroyed: Attachment destroyed
     cancel: Cancel
     choose_a_country: Choose a country

spec/dummy/db/migrate/20240724090242_create_store_patrons.rb

@@ -0,0 +1,11 @@
+class CreateStorePatrons < ActiveRecord::Migration[6.1]
+  def change
+    create_table :store_patrons do |t|
+      t.integer :store_id
+      t.integer :user_id
+      t.string :review
+
+      t.timestamps
+    end
+  end
+end

spec/dummy/db/schema.rb

@@ -171,7 +171,7 @@
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.integer "price_cents", default: 0, null: false
-    t.string "price_currency", default: "'USD'::character varying", null: false
+    t.string "price_currency", default: "USD", null: false
   end
 
   create_table "projects", force: :cascade do |t|
@@ -208,6 +208,14 @@
     t.index ["user_id"], name: "index_reviews_on_user_id"
   end
 
+  create_table "store_patrons", force: :cascade do |t|
+    t.integer "store_id"
+    t.integer "user_id"
+    t.string "review"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
   create_table "stores", force: :cascade do |t|
     t.string "name"
     t.string "size"

spec/system/avo/attach_with_additional_fields_spec.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe "Attach with extra fields", type: :system do
+  let!(:store) { create(:store) }
+  let!(:user) { create :user }
+  let!(:url) { "/admin/resources/stores/#{store.id}/patrons/new?view=show" }
+
+  it "allows to pass in data for extra fields" do
+    visit url
+    expect(page).to have_selector "input#fields_review"
+    expect(page).to have_selector "select#fields_related_id"
+
+    select user.name
+
+    expect {
+      click_button "Attach"
+    }.not_to change(StorePatron, :count)
+
+    expect(page).to_not have_text "Failed to attach User"
+
+    select user.name
+    fill_in id: "fields_review", with: "Toilet paper is phenomenal here."
+
+    expect {
+      click_button "Attach"
+    }.to change(StorePatron, :count).by 1
+    expect(page).to have_text "User attached"
+  end
+
+  it "saves attachment adhering to options like update_using" do
+    ENV["TEST_FILL_JOIN_RECORD"] = "1"
+    visit url
+    expect(page).to have_selector "input#fields_review"
+    expect(page).to have_selector "select#fields_related_id"
+
+    select user.name
+    fill_in id: "fields_review", with: "Toilet paper is phenomenal here."
+
+    expect {
+      click_button "Attach"
+    }.to change(StorePatron, :count)
+    expect(store.patronships.first.review).to eq ">> Toilet paper is phenomenal here. <<"
+  end
+end