Add support for Ransack 4

`extend` your class with `Alchemy::SearchableResource` to
provide necessary methods for Ransack to allow searching
and sorting attributes and associations.

By default it allows all string and text attributes to be searched
and all columns to be sorted. No association are allowed by default.

Existing `searchable_alchemy_resource_attributes` and
`alchemy_resource_relations` definitions are respected.

app/models/alchemy/base_record.rb

@@ -5,6 +5,8 @@ def self.table_name_prefix
   end
 
   class BaseRecord < ActiveRecord::Base
+    extend Alchemy::SearchableResource
+
     self.abstract_class = true
   end
 end

lib/alchemy/searchable_resource.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+module Alchemy
+  # Defines the methods that are needed to
+  # make a model searchable in Alchemy's admin search by Ransack.
+  module SearchableResource
+    SEARCHABLE_COLUMN_TYPES = %i[string text]
+
+    # Allow all string and text attributes to be searchable by Ransack.
+    def ransackable_attributes(_auth_object = nil)
+      searchable_alchemy_resource_attributes
+    end
+
+    # Allow all attributes to be sortable by Ransack.
+    def ransortable_attributes(_auth_object = nil)
+      columns.map(&:name)
+    end
+
+    # Allow all associations defined in +alchemy_resource_relations+ to be searchable by Ransack.
+    def ransackable_associations(_auth_object = nil)
+      searchable_alchemy_resource_associations
+    end
+
+    protected
+
+    def searchable_alchemy_resource_attributes
+      columns.select { |c| c.type.in?(SEARCHABLE_COLUMN_TYPES) }.map(&:name)
+    end
+
+    def searchable_alchemy_resource_associations
+      if respond_to?(:alchemy_resource_relations)
+        alchemy_resource_relations.keys.map!(&:to_s)
+      else
+        []
+      end
+    end
+  end
+end

lib/alchemy_cms.rb

@@ -51,6 +51,7 @@
 require_relative "alchemy/paths"
 require_relative "alchemy/permissions"
 require_relative "alchemy/resource"
+require_relative "alchemy/searchable_resource"
 require_relative "alchemy/tinymce"
 require_relative "alchemy/taggable"
 require_relative "alchemy/version"

spec/dummy/app/models/booking.rb

@@ -1,4 +1,5 @@
 # frozen_string_literal: true
 
 class Booking < ActiveRecord::Base
+  extend Alchemy::SearchableResource
 end

spec/dummy/app/models/event.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 class Event < ActiveRecord::Base
+  extend Alchemy::SearchableResource
   include Alchemy::Taggable
 
   validates_presence_of :name

spec/dummy/app/models/location.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 class Location < ActiveRecord::Base
+  extend Alchemy::SearchableResource
   include Alchemy::Taggable
   has_many :events
 end