Allow actions to be shown disabled instead of completely hidden

Closes #1765

Author: mshibuya

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

@@ -18,4 +18,8 @@ iframe.wysihtml5-sandbox, .wysihtml5-editor{
 
 .form-group.hidden_type {
   display: none;
+}
+
+.links .inline.list-inline .disabled span {
+  color: $gray-light;
 }

app/helpers/rails_admin/application_helper.rb

@@ -142,15 +142,23 @@ def menu_for(parent, abstract_model = nil, object = nil, only_icon = false) # pe
       actions = actions(parent, abstract_model, object).select { |a| a.http_methods.include?(:get) && a.show_in_menu }
       actions.collect do |action|
         wording = wording_for(:menu, action)
-        %(
-          <li title="#{wording if only_icon}" rel="#{'tooltip' if only_icon}" class="icon #{action.key}_#{parent}_link #{'active' if current_action?(action)}">
-            <a class="#{action.pjax? ? 'pjax' : ''}" href="#{rails_admin.url_for(action: action.action_name, controller: 'rails_admin/main', model_name: abstract_model.try(:to_param), id: (object.try(:persisted?) && object.try(:id) || nil))}">
-              <i class="#{action.link_icon}"></i>
-              <span#{only_icon ? " style='display:none'" : ''}>#{wording}</span>
-            </a>
-          </li>
-        )
-      end.join.html_safe
+        li_class = ['icon', "#{action.key}_#{parent}_link"].
+                   concat(current_action?(action) ? ['active'] : []).
+                   concat(action.enabled? ? [] : ['disabled'])
+        content_tag(:li, {class: li_class}.merge(only_icon ? {title: wording, rel: 'tooltip'} : {})) do
+          label = content_tag(:i, '', {class: action.link_icon}) + content_tag(:span, wording, (only_icon ? {style: 'display:none'} : {}))
+          if action.enabled? || !only_icon
+            href = if action.enabled?
+                     rails_admin.url_for(action: action.action_name, controller: 'rails_admin/main', model_name: abstract_model.try(:to_param), id: (object.try(:persisted?) && object.try(:id) || nil))
+                   else
+                     'javascript:void(0)'
+                   end
+            content_tag(:a, label, {href: href}.merge(action.pjax? ? {class: ['pjax']} : {}))
+          else
+            content_tag(:span, label)
+          end
+        end
+      end.join(' ').html_safe
     end
 
     def bulk_menu(abstract_model = @abstract_model)

spec/integration/actions/base_spec.rb

@@ -44,5 +44,28 @@
         end
       end
     end
+
+    context 'when used with #visible?' do
+      let!(:player) { FactoryBot.create(:player) }
+      before do
+        RailsAdmin.config do |config|
+          config.actions do
+            index
+            show
+            edit do
+              enabled false
+              visible true
+            end
+          end
+        end
+      end
+
+      it 'allows disabled links to be shown' do
+        visit index_path(model_name: 'player')
+        is_expected.to have_css('.edit_member_link.disabled span', text: /Edit/, visible: false)
+        visit show_path(model_name: 'player', id: player.id)
+        is_expected.to have_css('.edit_member_link.disabled a[href*="void(0)"]')
+      end
+    end
   end
 end