Use Orm Adapter gem to handle conditions/order from associations

Gemfile.lock

@@ -4,6 +4,7 @@ PATH
     simple_form (3.0.0.beta1)
       actionpack (>= 4.0.0.rc1, < 4.1)
       activemodel (>= 4.0.0.rc1, < 4.1)
+      orm_adapter (~> 0.4.0)
 
 GEM
   remote: https://rubygems.org/
@@ -31,6 +32,7 @@ GEM
     json (1.7.7)
     minitest (4.7.4)
     multi_json (1.7.2)
+    orm_adapter (0.4.0)
     rack (1.5.2)
     rack-test (0.6.2)
       rack (>= 1.0)

lib/simple_form.rb

@@ -1,4 +1,5 @@
 require 'action_view'
+require 'orm_adapter'
 require 'simple_form/action_view_extensions/form_helper'
 require 'simple_form/action_view_extensions/builder'
 require 'active_support/core_ext/hash/slice'

lib/simple_form/form_builder.rb

@@ -180,7 +180,7 @@ module SimpleForm
 
       options[:as] ||= :select
       options[:collection] ||= options.fetch(:collection) {
-        reflection.klass.all(reflection.options.slice(:conditions, :order))
+        reflection.klass.to_adapter.find_all(reflection.options.slice(:conditions, :order))
       }
 
       attribute = case reflection.macro

simple_form.gemspec

@@ -22,4 +22,5 @@ Gem::Specification.new do |s|
 
   s.add_dependency('activemodel', '>= 4.0.0.rc1', '< 4.1')
   s.add_dependency('actionpack', '>= 4.0.0.rc1', '< 4.1')
+  s.add_dependency('orm_adapter', '~> 0.4.0')
 end

test/support/models.rb

@@ -1,3 +1,15 @@
+Adapter = Struct.new(:all) do
+  def find_all(options)
+    if options[:conditions]
+      [all.first]
+    elsif options[:order]
+      [all.last]
+    else
+      all
+    end
+  end
+end
+
 Association = Struct.new(:klass, :name, :macro, :options)
 
 Column = Struct.new(:name, :type, :limit) do
@@ -12,15 +24,11 @@ Company = Struct.new(:id, :name) do
   include ActiveModel::Conversion
 
   def self.all(options={})
-    all = (1..3).map { |i| Company.new(i, "Company #{i}") }
+    (1..3).map { |i| new(i, "#{name} #{i}") }
+  end
 
-    if options[:conditions]
-      [all.first]
-    elsif options[:order]
-      [all.last]
-    else
-      all
-    end
+  def self.to_adapter
+    Adapter.new all
   end
 
   def persisted?
@@ -28,11 +36,7 @@ Company = Struct.new(:id, :name) do
   end
 end
 
-class Tag < Company
-  def self.all(options={})
-    (1..3).map { |i| Tag.new(i, "Tag #{i}") }
-  end
-end
+class Tag < Company; end
 
 TagGroup = Struct.new(:id, :name, :tags)