Support nullable boolean field. Closes #3145

app/assets/stylesheets/rails_admin/ra.widgets.scss

@@ -20,6 +20,15 @@ iframe.wysihtml5-sandbox, .wysihtml5-editor{
   display: none;
 }
 
+.form-group.boolean_type {
+  .success.active {
+    @extend .btn-success
+  }
+  .danger.active {
+    @extend .btn-danger
+  }
+}
+
 .links .inline.list-inline .disabled span {
   color: $gray-light;
 }

app/views/rails_admin/main/_form_boolean.html.haml

@@ -1,3 +1,10 @@
-.checkbox
-  %label{ style: 'display: block;' }
-    = form.send field.view_helper, field.method_name, field.html_attributes.reverse_merge({ value: field.form_value, checked: field.form_value.in?([true, '1']), required: field.required})
+- if field.nullable?
+  .btn-group{'data-toggle': 'buttons'}
+    - {'1': true, '0': false, '': nil}.each do |text, value|
+      %label.btn.btn-default{class: [field.css_classes[value], ("active" if field.form_value == value)]}
+        = form.radio_button field.method_name, text, field.html_attributes.reverse_merge({ checked: field.form_value == value, required: field.required})
+        = field.labels[value].html_safe
+- else
+  .checkbox
+    %label{ style: 'display: block;' }
+      = form.send field.view_helper, field.method_name, field.html_attributes.reverse_merge({ value: field.form_value, checked: field.form_value.in?([true, '1']), required: field.required})

lib/rails_admin/config/fields/types/boolean.rb

@@ -6,19 +6,32 @@ class Boolean < RailsAdmin::Config::Fields::Base
           # Register field type for the type loader
           RailsAdmin::Config::Fields::Types.register(self)
 
+          register_instance_option :labels do
+            {
+              true => %(<span class="icon icon-ok"></span>),
+              false => %(<span class="icon icon-remove"></span>),
+              nil => %(<span class="icon icon-minus"></span>),
+            }
+          end
+
+          register_instance_option :css_classes do
+            {
+              true => 'success',
+              false => 'danger',
+              nil => 'default',
+            }
+          end
+
+          register_instance_option :nullable? do
+            properties&.nullable?
+          end
+
           register_instance_option :view_helper do
             :check_box
           end
 
           register_instance_option :pretty_value do
-            case value
-            when false
-              %(<span class='label label-danger'>&#x2718;</span>)
-            when true
-              %(<span class='label label-success'>&#x2713;</span>)
-            else
-              %(<span class='label label-default'>&#x2012;</span>)
-            end.html_safe
+            %(<span class="label label-#{css_classes[form_value]}">#{labels[form_value]}</span>).html_safe
           end
 
           register_instance_option :export_value do
@@ -29,10 +42,21 @@ class Boolean < RailsAdmin::Config::Fields::Base
             :form_boolean
           end
 
+          def form_value
+            case value
+            when true, false
+              value
+            end
+          end
+
           # Accessor for field's help text displayed below input field.
           def generic_help
             ''
           end
+
+          def parse_input(params)
+            params[name] = params[name].presence if params.key?(name)
+          end
         end
       end
     end

spec/integration/actions/edit_spec.rb

@@ -833,7 +833,9 @@ class HelpTest < Tableless
     it 'is updatable without any error' do
       RailsAdmin.config FieldTest do
         edit do
-          field :open
+          field :open do
+            nullable false
+          end
         end
       end
       record = FieldTest.create

spec/integration/authorization/cancancan_spec.rb

@@ -135,7 +135,7 @@ def initialize(user)
     it 'POST /admin/player/new with unauthorized attribute value should raise access denied' do
       visit new_path(model_name: 'player')
       fill_in 'player[name]', with: 'Jackie Robinson'
-      uncheck 'player[suspended]'
+      choose name: 'player[suspended]', option: '0'
       expect { click_button 'Save' }.to raise_error(CanCan::AccessDenied)
     end
 
@@ -173,7 +173,7 @@ def initialize(user)
     it 'PUT /admin/player/new with unauthorized attribute value should raise access denied' do
       @player = FactoryBot.create :player
       visit edit_path(model_name: 'player', id: @player.id)
-      check 'player[retired]'
+      choose name: 'player[retired]', option: '1'
       expect { click_button 'Save' }.to raise_error(CanCan::AccessDenied)
     end
 

spec/integration/authorization/pundit_spec.rb

@@ -105,7 +105,7 @@
     it 'POST /admin/player/new with unauthorized attribute value should raise access denied' do
       visit new_path(model_name: 'player')
       fill_in 'player[name]', with: 'Jackie Robinson'
-      uncheck 'player[suspended]'
+      choose name: 'player[suspended]', option: '0'
       expect { click_button 'Save' }.to raise_error(Pundit::NotAuthorizedError)
     end
   end
@@ -118,7 +118,7 @@
     it 'PUT /admin/player/new with unauthorized attribute value should raise access denied' do
       @player = FactoryBot.create :player
       visit edit_path(model_name: 'player', id: @player.id)
-      check 'player[retired]'
+      choose name: 'player[retired]', option: '1'
       expect { click_button 'Save' }.to raise_error(Pundit::NotAuthorizedError)
     end
   end

spec/integration/fields/boolean_spec.rb

@@ -0,0 +1,59 @@
+require 'spec_helper'
+
+RSpec.describe 'Boolean field', type: :request do
+  subject { page }
+  let(:field_test) { FactoryBot.create :field_test }
+
+  context 'if nullable' do
+    before do
+      RailsAdmin.config FieldTest do
+        field :boolean_field
+      end
+    end
+
+    it 'shows 3 radio buttons' do
+      visit new_path(model_name: 'field_test')
+      is_expected.to have_content 'New Field test'
+      expect(all('[name="field_test[boolean_field]"]').map { |e| e['value'] }).to eq ['1', '0', '']
+    end
+
+    it 'can be updated' do
+      visit edit_path(model_name: 'field_test', id: field_test.id)
+      find('.boolean_type .icon-ok').sibling('input').click
+      click_button 'Save and edit'
+      expect(field_test.reload.boolean_field).to be true
+      find('.boolean_type .icon-remove').sibling('input').click
+      click_button 'Save and edit'
+      expect(field_test.reload.boolean_field).to be false
+      find('.boolean_type .icon-minus').sibling('input').click
+      click_button 'Save and edit'
+      expect(field_test.reload.boolean_field).to be nil
+    end
+  end
+
+  context 'if not nullable' do
+    before do
+      RailsAdmin.config FieldTest do
+        field :boolean_field do
+          nullable false
+        end
+      end
+    end
+
+    it 'shows a checkbox' do
+      visit new_path(model_name: 'field_test')
+      is_expected.to have_content 'New Field test'
+      is_expected.to have_css '[type="checkbox"][name="field_test[boolean_field]"]'
+    end
+
+    it 'can be updated' do
+      visit edit_path(model_name: 'field_test', id: field_test.id)
+      find('.boolean_type input').check
+      click_button 'Save and edit'
+      expect(field_test.reload.boolean_field).to be true
+      find('.boolean_type input').uncheck
+      click_button 'Save and edit'
+      expect(field_test.reload.boolean_field).to be false
+    end
+  end
+end

spec/rails_admin/config/fields/types/boolean_spec.rb

@@ -11,9 +11,9 @@
 
   describe '#pretty_value' do
     {
-      false => %(<span class='label label-danger'>&#x2718;</span>),
-      true => %(<span class='label label-success'>&#x2713;</span>),
-      nil => %(<span class='label label-default'>&#x2012;</span>),
+      false => %(<span class="label label-danger"><span class="icon icon-remove"></span></span>),
+      true => %(<span class="label label-success"><span class="icon icon-ok"></span></span>),
+      nil => %(<span class="label label-default"><span class="icon icon-minus"></span></span>),
     }.each do |field_value, expected_result|
       context "when field value is '#{field_value.inspect}'" do
         let(:test_object) { FieldTest.new(boolean_field: field_value) }