Display custom buttons after comming from relationship table

The code displays the custom buttons if the previous screen was a
provider screen ('@record') and displayed item ('@ display') is from the list
of classes supported by custom buttons ('APPLIES_TO_CLASS_BASE_MODELS')

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1635738

app/controllers/application_controller/buttons.rb

@@ -1,5 +1,6 @@
 module ApplicationController::Buttons
   extend ActiveSupport::Concern
+  include ApplicationHelper::Toolbar::Mixins::CustomButtonToolbarMixin
 
   included do
     include Mixins::PlaybookOptions
@@ -262,28 +263,6 @@ def open_url_after_dialog
   private
 
   BASE_MODEL_EXPLORER_CLASSES = [MiqGroup, MiqTemplate, Service, Switch, Tenant, User, Vm].freeze
-  APPLIES_TO_CLASS_BASE_MODELS = %w(AvailabilityZone CloudNetwork CloudObjectStoreContainer CloudSubnet CloudTenant
-                                    CloudVolume ContainerGroup ContainerImage ContainerNode ContainerProject
-                                    ContainerTemplate ContainerVolume EmsCluster ExtManagementSystem
-                                    GenericObject GenericObjectDefinition Host LoadBalancer
-                                    MiqGroup MiqTemp MiqTemplate NetworkRouter OrchestrationStack SecurityGroup Service
-                                    ServiceTemplate Storage Switch Tenant User Vm VmOrTemplate).freeze
-  def applies_to_class_model(applies_to_class)
-    # TODO: Give a better name for this concept, including ServiceTemplate using Service
-    # This should probably live in the model once this concept is defined.
-    unless APPLIES_TO_CLASS_BASE_MODELS.include?(applies_to_class)
-      raise ArgumentError, "Received: #{applies_to_class}, expected one of #{APPLIES_TO_CLASS_BASE_MODELS}"
-    end
-
-    case applies_to_class
-    when "ServiceTemplate"
-      Service
-    when "GenericObjectDefinition"
-      GenericObject
-    else
-      applies_to_class.constantize
-    end
-  end
 
   def custom_button_done
     url = SystemConsole.find_by(:vm => params[:id]).try(:url)
@@ -321,7 +300,7 @@ def sync_playbook_dialog(button)
 
   def custom_buttons(ids = nil, display_options = {})
     button = CustomButton.find(params[:button_id])
-    cls = applies_to_class_model(button.applies_to_class)
+    cls = custom_button_class_model(button.applies_to_class)
     @explorer = true if BASE_MODEL_EXPLORER_CLASSES.include?(cls)
     ids ||= params[:id]
     if ids.to_s == 'LIST'

app/controllers/mixins/custom_buttons.rb

@@ -1,5 +1,6 @@
 module Mixins::CustomButtons
   extend ActiveSupport::Concern
+  include ApplicationHelper::Toolbar::Mixins::CustomButtonToolbarMixin
 
   def custom_toolbar
     return nil unless self.class.instance_eval { @custom_buttons }
@@ -24,6 +25,8 @@ def custom_toolbar_simple
       Mixins::CustomButtons::Result.new(:single)
     elsif @lastaction == "show_list"
       Mixins::CustomButtons::Result.new(:list)
+    elsif relationship_table_screen?
+      Mixins::CustomButtons::Result.new(:list)
     elsif @display == 'generic_objects'
       @lastaction == 'generic_object' ? Mixins::CustomButtons::Result.new(:single) : Mixins::CustomButtons::Result.new(:list)
     end

app/helpers/application_helper/toolbar/mixins/custom_button_toolbar_mixin.rb

@@ -0,0 +1,49 @@
+module ApplicationHelper::Toolbar::Mixins::CustomButtonToolbarMixin
+  APPLIES_TO_CLASS_BASE_MODELS = %w(AvailabilityZone CloudNetwork CloudObjectStoreContainer CloudSubnet CloudTenant
+                                    CloudVolume ContainerGroup ContainerImage ContainerNode ContainerProject
+                                    ContainerTemplate ContainerVolume EmsCluster ExtManagementSystem
+                                    GenericObject GenericObjectDefinition Host LoadBalancer
+                                    MiqGroup MiqTemp MiqTemplate NetworkRouter OrchestrationStack SecurityGroup Service
+                                    ServiceTemplate Storage Switch Tenant User Vm VmOrTemplate).freeze
+
+  def custom_button_appliable_class?(model)
+    APPLIES_TO_CLASS_BASE_MODELS.include?(model)
+  end
+
+  def custom_button_class_model(applies_to_class)
+    # TODO: Give a better name for this concept, including ServiceTemplate using Service
+    # This should probably live in the model once this concept is defined.
+    unless custom_button_appliable_class?(applies_to_class)
+      raise ArgumentError, "Received: #{applies_to_class}, expected one of #{APPLIES_TO_CLASS_BASE_MODELS}"
+    end
+
+    case applies_to_class
+    when "ServiceTemplate"
+      Service
+    when "GenericObjectDefinition"
+      GenericObject
+    else
+      applies_to_class.constantize
+    end
+  end
+
+  # Indicates, whether the user has came from providers relationship screen
+  # or not
+  #
+  # Used to indicate if the custom buttons should be rendered
+  def relationship_table_screen?
+    return false if @display.nil? || @record.nil?
+
+    display_model = @display.camelize.singularize
+    providers = (EmsCloud.descendants +
+                 EmsInfra.descendants +
+                 EmsPhysicalInfra.descendants +
+                 ManageIQ::Providers::ContainerManager.descendants)
+
+    custom_button_model = custom_button_appliable_class?(display_model)
+    provider_screen = providers.any? { |provider| @record.instance_of?(provider) }
+    show_action = @lastaction == "show"
+
+    custom_button_model && provider_screen && show_action
+  end
+end

app/helpers/application_helper/toolbar_builder.rb

@@ -1,6 +1,7 @@
 class ApplicationHelper::ToolbarBuilder
   include MiqAeClassHelper
   include RestfulControllerMixin
+  include ApplicationHelper::Toolbar::Mixins::CustomButtonToolbarMixin
 
   def call(toolbar_name)
     build_toolbar(toolbar_name)
@@ -283,6 +284,8 @@ def custom_toolbar_class(toolbar_result)
     if @display == 'generic_objects'
       model = GenericObjectDefinition
       record = GenericObject.find_by(:id => @sb[:rec_id])
+    elsif relationship_table_screen?
+      model = @display.camelize.singularize.constantize
     else
       model = @record ? @record.class : model_for_custom_toolbar
     end