Merge pull request #2670 from semenovDL/feature/allow_multiple_config…

…uration_blocks

Feature/allow multiple configuration blocks

lib/rails_admin/config.rb

@@ -226,11 +226,9 @@ def model(entity, &block)
  end
  end
 
- if block
- @registry[key] = RailsAdmin::Config::LazyModel.new(entity, &block)
- else
- @registry[key] ||= RailsAdmin::Config::LazyModel.new(entity)
- end
+ @registry[key] ||= RailsAdmin::Config::LazyModel.new(entity)
+ @registry[key].add_deferred_block(&block) if block
+ @registry[key]
  end
 
  def default_hidden_fields=(fields)

lib/rails_admin/config/lazy_model.rb

@@ -5,13 +5,53 @@ module Config
  class LazyModel < BasicObject
  def initialize(entity, &block)
  @entity = entity
- @deferred_block = block
+ @deferred_blocks = [*block]
+ @existing_blocks = []
+ end
+
+ def add_deferred_block(&block)
+ @deferred_blocks << block
  end
 
  def target
- unless @model
- @model = ::RailsAdmin::Config::Model.new(@entity)
- @model.instance_eval(&@deferred_block) if @deferred_block
+ @model ||= ::RailsAdmin::Config::Model.new(@entity)
+ # When evaluating multiple configuration blocks, the order of
+ # execution is important. As one would expect (in my opinion),
+ # options defined within a resource should take precedence over
+ # more general options defined in an initializer. This way,
+ # general settings for a number of resources could be specified
+ # in the initializer, while models could override these settings
+ # later, if required.
+ #
+ # CAVEAT: It cannot be guaranteed that blocks defined in an initializer
+ # will be loaded (and adde to @deferred_blocks) first. For instance, if
+ # the initializer references a model class before defining
+ # a RailsAdmin configuration block, the configuration from the
+ # resource will get added to @deferred_blocks first:
+ #
+ # # app/models/some_model.rb
+ # class SomeModel
+ # rails_admin do
+ # :
+ # end
+ # end
+ #
+ # # config/initializers/rails_admin.rb
+ # model = 'SomeModel'.constantize # blocks from SomeModel get loaded
+ # model.config model do # blocks from initializer gets loaded
+ # :
+ # end
+ #
+ # Thus, sort all blocks to excute for a resource by Proc.source_path,
+ # to guarantee that blocks from 'config/initializers' evaluate before
+ # blocks defined within a model class.
+ unless @deferred_blocks.empty?
+ @existing_blocks += @deferred_blocks
+ @existing_blocks.
+ partition { |block| block.source_location.first =~ %r{config\/initializers} }.
+ flatten.
+ each { |block| @model.instance_eval(&block) }
+ @deferred_blocks = []
  end
  @model
  end

spec/rails_admin/config_spec.rb

@@ -270,6 +270,47 @@ class RecursivelyEmbedsMany
  expect(RailsAdmin.config.parent_controller).to eq 'TestController'
  end
  end
+
+ describe '.model' do
+ let(:fields) { described_class.model(Team).fields }
+ before do
+ described_class.model Team do
+ field :players do
+ visible false
+ end
+ end
+ end
+ context 'when model expanded' do
+ before do
+ described_class.model(Team) do
+ field :fans
+ end
+ end
+ it 'execute all passed blocks' do
+ expect(fields.map(&:name)).to match_array %i(players fans)
+ end
+ end
+ context 'when expand redefine behavior' do
+ before do
+ described_class.model Team do
+ field :players
+ end
+ end
+ it 'execute all passed blocks' do
+ expect(fields.find { |f| f.name == :players }.visible).to be true
+ end
+ end
+ context 'when model expanded in config' do
+ let(:block) { proc { field :players } }
+ before do
+ allow(block).to receive(:source_location).and_return(['config/initializers/rails_admin.rb'])
+ described_class.model(Team, &block)
+ end
+ it 'executes first' do
+ expect(fields.find { |f| f.name == :players }.visible).to be false
+ end
+ end
+ end
 end
 
 module ExampleModule