Evaluate visibility expressions for CustomButtons

app/models/custom_button.rb

@@ -140,6 +140,12 @@ def evaluate_enablement_expression_for(object)
     enablement_expression.lenient_evaluate(object)
   end
 
+  def evaluate_visibility_expression_for(object)
+    return true unless visibility_expression
+    return false if visibility_expression && !object # object == nil, method is called for list of objects
+    visibility_expression.lenient_evaluate(object)
+  end
+
   # End - Helper methods to support moving automate columns to resource_actions table
 
   def self.parse_uri(uri)

app/models/custom_button_set.rb

@@ -26,6 +26,41 @@ def self.applies_to_all_instances(class_name)
     applies_to_class(class_name).where("set_data not like ?", "%:applies_to_id%")
   end
 
+  # Params:
+  #   custom_button_sets: <Array>CustomButtonSet
+  #   object: for this object are evaluated visibility_expression of CustomButtons
+  #           one CustomButtonSet contains any CustomButtons,
+  #           CustomButtonSet has stored this ids of CustomButtons in array CustomButton#set_data[:button_order]
+  # Returns:
+  #   <Array>CustomButtonSet
+  #
+  # example:
+  # let's have:
+  # custom_buttons_set =
+  #   <Array> [<CustomButtonSet> id: 10000000000075,
+  #     set_data:
+  #       {:button_order=> [1, 2]}, list ids of custom buttons in custom button set (group of buttons in UI)
+  # ... ]
+  # object = Vm.first
+  #
+  # then CustomButtonSet.filter_with_visibility_expression(custom_button_sets, object) returns:
+  #  - same custom_button_sets array when all visibility expressions are not populated(CustomButton#visibility_expression = nil)
+  #  - same custom_button_sets array but with filtered list custom buttons ids in each custom button set from
+  #    custom_button_sets when any visibility expression is evaluated to true
+  #    - ids of custom buttons with visibility expression which are evaluated to false are removed from CustomButtonSet#set_data[:button_order]
+  #  - filtered custom_button_sets array when all visibilty expression custom buttons have been evaluated to false
+  def self.filter_with_visibility_expression(custom_button_sets, object)
+    custom_button_sets.each_with_object([]) do |custom_button_set, ret|
+      custom_button_from_set = CustomButton.where(:id => custom_button_set.set_data[:button_order]).select(:id, :visibility_expression)
+      filtered_ids = custom_button_from_set.select { |x| x.evaluate_visibility_expression_for(object) }.pluck(:id)
+      if filtered_ids.present?
+        custom_button_set.set_data[:button_order] = filtered_ids
+        ret << custom_button_set
+      end
+      ret
+    end
+  end
+
   def deep_copy(options)
     raise ArgumentError, "options[:owner] is required" if options[:owner].blank?
 

spec/models/custom_button_set_spec.rb

@@ -21,6 +21,40 @@
     end
   end
 
+  describe '.filter_with_visibility_expression' do
+    let(:vm_1)              { FactoryGirl.create(:vm_vmware, :name => 'vm_1') }
+    let(:custom_button_1)   { FactoryGirl.create(:custom_button, :applies_to => vm_1) }
+    let(:miq_expression)    { MiqExpression.new('EQUAL' => {'field' => 'Vm-name', 'value' => "vm_1"}) }
+    let(:custom_button_2)   { FactoryGirl.create(:custom_button, :applies_to => vm_1, :visibility_expression => miq_expression) }
+    let(:set_data)          { {:applies_to_class => "Vm", :button_order => [custom_button_1.id, custom_button_2.id]} }
+    let(:custom_button_set) { FactoryGirl.create(:custom_button_set, :name => "set_1", :set_data => set_data) }
+
+    context 'when all CustomButtons#visibility_expression=nil' do
+      let(:miq_expression) { nil }
+
+      it 'returns same array CustomButtonSet as input' do
+        expect(described_class.filter_with_visibility_expression([custom_button_set], vm_1)).to eq([custom_button_set])
+      end
+    end
+
+    context 'when any visibility_expression is evaluated to false and any to true' do
+      let(:miq_expression_false) { MiqExpression.new('EQUAL' => {'field' => 'Vm-name', 'value' => "vm_2"}) }
+      let(:custom_button_1)      { FactoryGirl.create(:custom_button, :applies_to => vm_1, :visibility_expression => miq_expression_false) }
+
+      it 'returns filtered array of CustomButtonSet and CustomButtons' do
+        set = described_class.filter_with_visibility_expression([custom_button_set], vm_1).first
+        expect(set.set_data[:button_order]).to eq([custom_button_2.id])
+      end
+
+      context 'all CustomButtons#visibility_expression are evaluated to false' do
+        let(:miq_expression)    { MiqExpression.new('EQUAL' => {'field' => 'Vm-name', 'value' => 'vm_2'}) }
+        it 'returns empty array of CustomButtonSet' do
+          expect(described_class.filter_with_visibility_expression([custom_button_set], vm_1)).to be_empty
+        end
+      end
+    end
+  end
+
   it "#deep_copy" do
     service_template1 = FactoryGirl.create(:service_template)
     service_template2 = FactoryGirl.create(:service_template)