Make numeric fields work with validates_numericality_of using symbols and procs

lib/simple_form/inputs/numeric_input.rb

@@ -35,7 +35,7 @@ module SimpleForm
 
       def minimum_value(validator_options)
         if integer? && validator_options.key?(:greater_than)
-          validator_options[:greater_than] + 1
+          sanitize_validator_option(validator_options[:greater_than]) + 1
         else
           validator_options[:greater_than_or_equal_to]
         end
@@ -43,7 +43,7 @@ module SimpleForm
 
       def maximum_value(validator_options)
         if integer? && validator_options.key?(:less_than)
-          validator_options[:less_than] - 1
+          sanitize_validator_option(validator_options[:less_than]) - 1
         else
           validator_options[:less_than_or_equal_to]
         end
@@ -52,6 +52,14 @@ module SimpleForm
       def find_numericality_validator
         attribute_validators.find { |v| ActiveModel::Validations::NumericalityValidator === v }
       end
+
+      private
+
+      def sanitize_validator_option(option)
+        return option if option.is_a?(Numeric)
+        return object.send(option) if option.is_a?(Symbol)
+        return option.call(object) if option.respond_to?(:call)
+      end
     end
   end
 end

test/inputs_test.rb

@@ -204,6 +204,22 @@ class InputTest < ActionView::TestCase
     assert_select 'input[min=18]'
   end
 
+  test 'input should infer min value from integer attributes with greater than validation using symbol' do
+    with_input_for @validating_user, :amount, :float
+    assert_no_select 'input[min]'
+
+    with_input_for @validating_user, :amount, :integer
+    assert_select 'input[min=11]'
+  end
+
+  test 'input should infer min value from integer attributes with greater than validation using proc' do
+    with_input_for @other_validating_user, :amount, :float
+    assert_no_select 'input[min]'
+
+    with_input_for @other_validating_user, :amount, :integer
+    assert_select 'input[min=20]'
+  end
+
   test 'input should infer max value from attributes with less than validation' do
     with_input_for @other_validating_user, :age, :float
     assert_no_select 'input[max]'
@@ -212,6 +228,22 @@ class InputTest < ActionView::TestCase
     assert_select 'input[max=99]'
   end
 
+  test 'input should infer max value from attributes with less than validation using symbol' do
+    with_input_for @validating_user, :amount, :float
+    assert_no_select 'input[max]'
+
+    with_input_for @validating_user, :amount, :integer
+    assert_select 'input[max=99]'
+  end
+
+  test 'input should infer max value from attributes with less than validation using proc' do
+    with_input_for @other_validating_user, :amount, :float
+    assert_no_select 'input[max]'
+
+    with_input_for @other_validating_user, :amount, :integer
+    assert_select 'input[max=118]'
+  end
+
   test 'input should infer step value only from integer attribute' do
     with_input_for @validating_user, :age, :float
     assert_no_select 'input[step]'

test/support/models.rb

@@ -40,7 +40,8 @@ class User
 
   attr_accessor :id, :name, :company, :company_id, :time_zone, :active, :description, :created_at, :updated_at,
     :credit_limit, :age, :password, :delivery_time, :born_at, :special_company_id, :country, :url, :tag_ids,
-    :avatar, :home_picture, :email, :status, :residence_country, :phone_number, :post_count, :lock_version
+    :avatar, :home_picture, :email, :status, :residence_country, :phone_number, :post_count, :lock_version,
+    :amount
 
   def initialize(options={})
     options.each do |key, value|
@@ -72,6 +73,7 @@ class User
       when :updated_at    then :timestamp
       when :lock_version  then :integer
       when :home_picture  then :string
+      when :amount        then :integer
     end
     Column.new(attribute, column_type, limit)
   end
@@ -124,6 +126,18 @@ class ValidatingUser < User
     :greater_than_or_equal_to => 18,
     :less_than_or_equal_to => 99,
     :only_integer => true
+  validates_numericality_of :amount,
+    :greater_than => :min_amount,
+    :less_than => :max_amount,
+    :only_integer => true
+
+  def min_amount
+    10
+  end
+
+  def max_amount
+    100
+  end
 end
 
 class OtherValidatingUser < User
@@ -132,4 +146,8 @@ class OtherValidatingUser < User
     :greater_than => 17,
     :less_than => 100,
     :only_integer => true
+  validates_numericality_of :amount,
+    :greater_than => Proc.new { |user| user.age },
+    :less_than => Proc.new { |user| user.age + 100},
+    :only_integer => true
 end

test/test_helper.rb

@@ -58,6 +58,7 @@ class ActionView::TestCase
       :description => 'Hello!',
       :created_at => Time.now,
       :age => 19,
+      :amount => 15,
       :company => 1
     }.merge(options))