diff --git a/.rubocop.yml b/.rubocop.yml
index ee6079d0..e82b7c35 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -4,13 +4,16 @@ inherit_gem:
 
 inherit_from: .rubocop_todo.yml
 
+inherit_mode:
+  merge:
+    - Exclude
+
 Layout/ArgumentAlignment:
   EnforcedStyle: with_fixed_indentation
   IndentationWidth: 2
 
 Rails/SkipsModelValidations:
   Exclude:
-    - 'db/migrate/**/*'
     - 'db/migrate_foreman/**/*'
 
 Style/FormatStringToken:
diff --git a/app/controllers/concerns/foreman_puppet_enc/extensions/hostgroups_controller_extensions.rb b/app/controllers/concerns/foreman_puppet_enc/extensions/hostgroups_controller_extensions.rb
new file mode 100644
index 00000000..7a35fcae
--- /dev/null
+++ b/app/controllers/concerns/foreman_puppet_enc/extensions/hostgroups_controller_extensions.rb
@@ -0,0 +1,38 @@
+module ForemanPuppetEnc
+  module Extensions
+    module HostgroupsControllerExtensions
+      extend ActiveSupport::Concern
+
+      PUPPET_AJAX_REQUESTS = %w[environment_selected puppetclass_parameters].freeze
+
+      included do
+        alias_method :ajax_request_for_puppet_hostgroup_extensions, :ajax_request
+        alias_method :taxonomy_scope_for_puppet_hostgroup_extensions, :taxonomy_scope
+
+        before_action :ajax_request_for_puppet_hostgroup_extensions, only: PUPPET_AJAX_REQUESTS
+        before_action :taxonomy_scope_for_puppet_hostgroup_extensions, only: PUPPET_AJAX_REQUESTS
+
+        helper ForemanPuppetEnc::HostsAndHostgroupsHelper
+      end
+
+      def environment_selected
+        env_id = params[:environment_id] || params[:hostgroup][:environment_id]
+        return not_found if env_id.to_i.positive? && !(@environment = Environment.find(env_id))
+
+        refresh_hostgroup
+        @hostgroup.environment = @environment if @environment
+
+        @hostgroup.puppetclasses = Puppetclass.where(id: params[:hostgroup][:puppetclass_ids])
+        @hostgroup.config_groups = ConfigGroup.where(id: params[:hostgroup][:config_group_ids])
+        render partial: 'hosts/form_puppet_enc_tab', locals: { obj: @hostgroup, resource_type: :hostgroup }
+      end
+
+      def puppetclass_parameters
+        Taxonomy.as_taxonomy @organization, @location do
+          render partial: 'foreman_puppet_enc/puppetclasses/classes_parameters',
+                 locals: { obj: refresh_hostgroup }
+        end
+      end
+    end
+  end
+end
diff --git a/app/controllers/concerns/foreman_puppet_enc/extensions/hosts_controller_extensions.rb b/app/controllers/concerns/foreman_puppet_enc/extensions/hosts_controller_extensions.rb
index 1664b9c5..74cf1e15 100644
--- a/app/controllers/concerns/foreman_puppet_enc/extensions/hosts_controller_extensions.rb
+++ b/app/controllers/concerns/foreman_puppet_enc/extensions/hosts_controller_extensions.rb
@@ -24,7 +24,7 @@ module HostsControllerExtensions
 
         set_callback :set_class_variables, :after, :set_puppet_class_variables
 
-        helper ForemanPuppetEnc::HostsHelper
+        helper ForemanPuppetEnc::HostsAndHostgroupsHelper
       end
 
       def hostgroup_or_environment_selected
@@ -32,7 +32,7 @@ def hostgroup_or_environment_selected
         set_class_variables(@host)
         Taxonomy.as_taxonomy @organization, @location do
           if @environment || @hostgroup
-            render partial: 'puppetclasses/class_selection', locals: { obj: @host, resource_type: :host }
+            render partial: 'hosts/form_puppet_enc_tab', locals: { obj: @host, resource_type: :host }
           else
             logger.info 'environment_id or hostgroup_id is required to render puppetclasses'
           end
@@ -41,7 +41,7 @@ def hostgroup_or_environment_selected
 
       def puppetclass_parameters
         Taxonomy.as_taxonomy @organization, @location do
-          render partial: 'puppetclasses/classes_parameters', locals: { obj: refresh_host }
+          render partial: 'foreman_puppet_enc/puppetclasses/classes_parameters', locals: { obj: refresh_host }
         end
       end
 
diff --git a/app/helpers/foreman_puppet_enc/hosts_and_hostgroups_helper.rb b/app/helpers/foreman_puppet_enc/hosts_and_hostgroups_helper.rb
new file mode 100644
index 00000000..dfacf7c9
--- /dev/null
+++ b/app/helpers/foreman_puppet_enc/hosts_and_hostgroups_helper.rb
@@ -0,0 +1,84 @@
+module ForemanPuppetEnc
+  module HostsAndHostgroupsHelper
+    UI.register_host_description do
+      multiple_actions_provider :puppet_host_multiple_actions
+    end
+
+    # TODO: remove me - prevents the puppetclass tab duplication
+    def puppetclasses_tab(puppetclasses_receiver)
+    end
+
+    def puppet_host_multiple_actions
+      if ForemanPuppetEnc.extracted_from_core?
+        [{ action: [_('Change Environment'), foreman_puppet_enc.select_multiple_environment_hosts_path], priority: 200 }]
+      else
+        []
+      end
+    end
+
+    def host_puppet_environment_field(form, select_options = {}, html_options = {})
+      select_options = {
+        include_blank: true,
+        disable_button: _(::HostsAndHostgroupsHelper::INHERIT_TEXT),
+        disable_button_enabled: inherited_by_default?(:environment_id, form.object),
+        user_set: user_set?(:environment_id),
+      }.deep_merge(select_options)
+
+      html_options = {
+        data: {
+          host: {
+            id: form.object.id,
+          },
+        },
+      }.deep_merge(html_options)
+
+      puppet_environment_field(
+        form,
+        accessible_resource(form.object, :environment),
+        select_options,
+        html_options
+      )
+    end
+
+    def hostgroup_puppet_environment_field(form, select_options = {}, html_options = {})
+      select_options = {
+        include_blank: blank_or_inherit_f(form, :environment),
+      }.deep_merge(select_options)
+
+      puppet_environment_field(
+        form,
+        accessible_resource(form.object, :environment),
+        select_options,
+        html_options
+      )
+    end
+
+    def puppet_environment_field(form, environments_choice, select_options = {}, html_options = {})
+      html_options = {
+        onchange: 'tfm.puppetEnc.hostForm.updatePuppetclasses(this)',
+        help_inline: :indicator,
+      }.deep_merge(html_options)
+
+      select_f(
+        form,
+        :environment_id,
+        environments_choice,
+        :id,
+        :to_label,
+        select_options,
+        html_options
+      )
+    end
+
+    def puppetclasses_with_parameters_for(obj)
+      classes = obj.all_puppetclasses
+      ids = classes.reorder(nil).pluck(:id)
+      class_vars = ForemanPuppetEnc::PuppetclassLookupKey.reorder(nil)
+                                                         .joins(:environment_classes)
+                                                         .where(EnvironmentClass.arel_table[:puppetclass_id].in(ids))
+                                                         .distinct
+                                                         .pluck('environment_classes.puppetclass_id')
+      classes.where(id: class_vars)
+    end
+  end
+end
diff --git a/app/helpers/foreman_puppet_enc/hosts_helper.rb b/app/helpers/foreman_puppet_enc/hosts_helper.rb
deleted file mode 100644
index df827d4f..00000000
--- a/app/helpers/foreman_puppet_enc/hosts_helper.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-module ForemanPuppetEnc
-  module HostsHelper
-    UI.register_host_description do
-      multiple_actions_provider :puppet_host_multiple_actions
-    end
-
-    def puppet_host_multiple_actions
-      if ForemanPuppetEnc.extracted_from_core?
-        [{ action: [_('Change Environment'), foreman_puppet_enc.select_multiple_environment_hosts_path], priority: 200 }]
-      else
-        []
-      end
-    end
-  end
-end
diff --git a/app/views/hosts/_form_puppet_enc_tab.html.erb b/app/views/hosts/_form_puppet_enc_tab.html.erb
index b0682ab9..3aebbe2a 100644
--- a/app/views/hosts/_form_puppet_enc_tab.html.erb
+++ b/app/views/hosts/_form_puppet_enc_tab.html.erb
@@ -1,14 +1,23 @@
-<% obj = local_assigns[pagelet.opts[:resource_type]] %>
+<% resource_type ||= pagelet.opts[:resource_type] %>
+<% obj ||= local_assigns[resource_type] %>
+<% if resource_type == :host %>
+<span id="puppet_klasses_reload_url" data-url="<%= foreman_puppet_enc.hostgroup_or_environment_selected_hosts_path %>"></span>
+<% elsif resource_type == :hostgroup %>
+<span id="puppet_klasses_reload_url" data-url="<%= foreman_puppet_enc.environment_selected_hostgroups_path %>"></span>
+<% end %>
 <% if @environment.present? || obj.environment.present? %>
   <% if accessible_resource_records(:config_group).exists? %>
-    <%= render 'foreman_puppet_enc/config_groups/config_groups_selection', obj: obj, resource_type: pagelet.opts[:resource_type] %>
+    <%= render 'foreman_puppet_enc/config_groups/config_groups_selection', obj: obj, resource_type: resource_type %>
   <% end %>
 
-  <%= render 'foreman_puppet_enc/puppetclasses/class_selection', obj: obj, resource_type: pagelet.opts[:resource_type] %>
+  <%= render 'foreman_puppet_enc/puppetclasses/class_selection', obj: obj, resource_type: resource_type %>
 <% else %>
   <%= alert(class: alert_class(:info),
             header: _('Notice'),
             text: _('Please select an environment first')) %>
 <% end %>
 
-
+<fieldset id="puppet_klasses_parameters" data-url="<%= foreman_puppet_enc.url_for(action: :puppetclass_parameters, only_path: true) %>">
+  <h2><%= _('Puppet Class Parameters') %></h2>
+  <%= render 'foreman_puppet_enc/puppetclasses/classes_parameters', obj: obj %>
+</fieldset>
diff --git a/app/views/hosts/foreman_puppet_enc/_form_main_tab_fields.html.erb b/app/views/hosts/foreman_puppet_enc/_form_main_tab_fields.html.erb
new file mode 100644
index 00000000..75f43036
--- /dev/null
+++ b/app/views/hosts/foreman_puppet_enc/_form_main_tab_fields.html.erb
@@ -0,0 +1 @@
+<%= public_send("#{pagelet.opts[:resource_type]}_puppet_environment_field", form) %>
diff --git a/config/routes.rb b/config/routes.rb
index b58e8460..89cbfb44 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -26,10 +26,19 @@
 
   resources :hosts, only: [], controller: '/hosts' do
     collection do
+      post 'hostgroup_or_environment_selected'
+      post 'puppetclass_parameters'
       match 'select_multiple_environment', via: %i[get post]
       post 'update_multiple_environment'
     end
   end
+
+  resources :hostgroups, only: [], controller: '/hostgroups' do
+    collection do
+      post 'environment_selected'
+      post 'puppetclass_parameters'
+    end
+  end
 end
 
 Foreman::Application.routes.draw do
diff --git a/lib/foreman_puppet_enc/engine.rb b/lib/foreman_puppet_enc/engine.rb
index 5cbcfccd..8ae3c6c0 100644
--- a/lib/foreman_puppet_enc/engine.rb
+++ b/lib/foreman_puppet_enc/engine.rb
@@ -26,6 +26,7 @@ class Engine < ::Rails::Engine
       # To stay
       LookupValue.include ForemanPuppetEnc::PuppetLookupValueExtensions
       HostsController.include ForemanPuppetEnc::Extensions::HostsControllerExtensions
+      HostgroupsController.include ForemanPuppetEnc::Extensions::HostgroupsControllerExtensions
     end
 
     rake_tasks do
diff --git a/lib/foreman_puppet_enc/register.rb b/lib/foreman_puppet_enc/register.rb
index bf2af488..1ecff2b5 100644
--- a/lib/foreman_puppet_enc/register.rb
+++ b/lib/foreman_puppet_enc/register.rb
@@ -143,17 +143,32 @@
     end
   end
 
+  unless ForemanPuppetEnc.extracted_from_core?
+    Rails.application.config.after_initialize do
+      list = Pagelets::Manager.instance.instance_variable_get(:@pagelets)['hosts/_form'][:main_tabs]
+      core_pagelet = list.detect { |pagelet| pagelet.opts[:id] == :puppet_klasses }
+      list.delete(core_pagelet)
+    end
+  end
+
   # extend host(group) form with puppet ENC Tab
   %i[host hostgroup].each do |resource_type|
     host_onlyif = ->(host, context) { context.send(:accessible_resource, host, :smart_proxy, :name, association: :puppet_proxy).present? }
     extend_page("#{resource_type}s/_form") do |context|
       context.add_pagelet :main_tabs,
-        id: :puppet_klasses,
+        id: :puppet_enc_tab,
         name: N_('Puppet ENC'),
         partial: 'hosts/form_puppet_enc_tab',
         resource_type: resource_type,
         priority: 100,
         onlyif: (host_onlyif if resource_type == :host)
+
+      if ForemanPuppetEnc.extracted_from_core?
+        context.add_pagelet :main_tab_fields,
+          partial: 'hosts/foreman_puppet_enc/form_main_tab_fields',
+          resource_type: resource_type,
+          priority: 100
+      end
     end
   end
 end
diff --git a/test/controllers/foreman_puppet_enc/hostgroups_controller_test.rb b/test/controllers/foreman_puppet_enc/hostgroups_controller_test.rb
new file mode 100644
index 00000000..c329fd50
--- /dev/null
+++ b/test/controllers/foreman_puppet_enc/hostgroups_controller_test.rb
@@ -0,0 +1,73 @@
+require 'test_puppet_enc_helper'
+
+module ForemanPuppetEnc
+  class HostgroupsControllerTest < ActionController::TestCase
+    tests ::HostgroupsController
+
+    setup do
+      @routes = ForemanPuppetEnc::Engine.routes
+    end
+
+    describe '#environment_selected' do
+      setup do
+        @environment = FactoryBot.create(:environment)
+        @puppetclass = FactoryBot.create(:puppetclass)
+        @hostgroup = FactoryBot.create(:hostgroup, environment: @environment)
+        @params = {
+          id: @hostgroup.id,
+          hostgroup: {
+            name: @hostgroup.name,
+            environment_id: '',
+            puppetclass_ids: [@puppetclass.id],
+          },
+        }
+      end
+
+      test 'should return the selected puppet classes on environment change' do
+        assert_equal 0, @hostgroup.puppetclasses.length
+
+        post :environment_selected, params: @params, session: set_session_user, xhr: true
+        assert_equal(1, assigns(:hostgroup).puppetclasses.length)
+        assert_include assigns(:hostgroup).puppetclasses, @puppetclass
+      end
+
+      context 'environment_id param is set' do
+        test 'it will take the hostgroup params environment_id' do
+          other_environment = FactoryBot.create(:environment)
+          @params[:hostgroup][:environment_id] = other_environment.id
+
+          post :environment_selected, params: @params, session: set_session_user, xhr: true
+          assert_equal assigns(:environment), other_environment
+        end
+      end
+
+      test 'should not escape lookup values on environment change' do
+        skip 'Needs fully extracted puppet' unless ForemanPuppetEnc.extracted_from_core?
+        hostgroup = FactoryBot.create(:hostgroup, environment: @environment, puppetclass_ids: [@puppetclass.id])
+        lookup_key = FactoryBot.create(:puppetclass_lookup_key, :array, default_value: %w[a b],
+                                                                        override: true,
+                                                                        puppetclass: @puppetclass,
+                                                                        overrides: { "hostgroup=#{hostgroup.name}" => %w[c d] })
+        lookup_value = lookup_key.lookup_values.first
+        FactoryBot.create(:environment_class, puppetclass: @puppetclass, environment: @environment, puppetclass_lookup_key: lookup_key)
+
+        # sending exactly what the host form would send which is lookup_value.value_before_type_cast
+        lk = { 'lookup_values_attributes' => { lookup_key.id.to_s => { 'value' => lookup_value.value_before_type_cast,
+                                                                       'id' => lookup_value.id,
+                                                                       'lookup_key_id' => lookup_key.id,
+                                                                       '_destroy' => false } } }
+
+        params = {
+          hostgroup_id: hostgroup.id,
+          hostgroup: hostgroup.attributes.merge(lk),
+        }
+
+        # environment change calls puppetclass_parameters which caused the extra escaping
+        post :puppetclass_parameters, params: params, session: set_session_user, xhr: true
+
+        # if this was escaped during refresh_host the value in response.body after unescapeHTML would include "[\\\"c\\\",\\\"d\\\"]"
+        assert_includes CGI.unescapeHTML(response.body), '["c","d"]'
+      end
+    end
+  end
+end
diff --git a/test/controllers/foreman_puppet_enc/hosts_controller_test.rb b/test/controllers/foreman_puppet_enc/hosts_controller_test.rb
index 1fc2e816..1e9901a7 100644
--- a/test/controllers/foreman_puppet_enc/hosts_controller_test.rb
+++ b/test/controllers/foreman_puppet_enc/hosts_controller_test.rb
@@ -18,8 +18,8 @@ class HostsControllerTest < ActionController::TestCase
     let(:environment2) { FactoryBot.create(:environment, organizations: [org], locations: [loc]) }
     let(:hostgroup) { FactoryBot.create(:hostgroup, environment: environment2, organizations: [org], locations: [loc]) }
     let(:host_defaults) { { hostgroup: hostgroup, environment: environment1, organization: org, location: loc } }
-    let(:host1) { FactoryBot.create(:host, host_defaults) }
-    let(:host2) { FactoryBot.create(:host, host_defaults) }
+    let(:host1) { FactoryBot.create(:host, :with_puppetclass, host_defaults) }
+    let(:host2) { FactoryBot.create(:host, :with_puppetclass, host_defaults) }
 
     test 'user with edit host rights with update environments should change environments' do
       @request.env['HTTP_REFERER'] = '/hosts'
@@ -43,5 +43,78 @@ class HostsControllerTest < ActionController::TestCase
       assert_equal hostgroup.environment_id, host1.reload.environment_id
       assert_equal hostgroup.environment_id, host2.reload.environment_id
     end
+
+    describe '#edit' do
+      setup { @routes = Rails.application.routes }
+
+      test 'lookup value and description should be html escaped' do
+        skip 'Needs complete migration to be done' unless ForemanPuppetEnc.extracted_from_core?
+        host = FactoryBot.create(:host, :with_puppetclass)
+        FactoryBot.create(:puppetclass_lookup_key,
+          default_value: "<script>alert('hacked!');</script>",
+          description: "<script>alert('hacked!');</script>",
+          puppetclass: host1.puppetclasses.first)
+        get :edit, params: { id: host.to_param }, session: set_session_user
+        assert_not response.body.include?('<script>alert(')
+        assert_includes response.body, '&lt;script&gt;alert('
+        assert_equal 2, response.body.scan('&lt;script&gt;alert(').count
+      end
+    end
+
+    describe '#hostgroup_or_environment_selected' do
+      let(:hostgroup) { FactoryBot.create(:hostgroup, organizations: [org], locations: [loc]) }
+
+      test 'choosing only one of hostgroup or environment renders classes' do
+        post :hostgroup_or_environment_selected, params: {
+          host_id: nil,
+          host: {
+            environment_id: environment1.id,
+          },
+        }, session: set_session_user, xhr: true
+        assert_response :success
+        assert_template partial: 'hosts/_form_puppet_enc_tab'
+      end
+
+      test 'choosing both hostgroup and environment renders classes' do
+        post :hostgroup_or_environment_selected, params: {
+          host_id: host1.id,
+          host: {
+            environment_id: environment1.id,
+            hostgroup_id: hostgroup.id,
+          },
+        }, session: set_session_user, xhr: true
+        assert_response :success
+        assert_template partial: 'hosts/_form_puppet_enc_tab'
+      end
+
+      test 'should not escape lookup values on environment change' do
+        host = FactoryBot.create(:host, :with_environment, :with_puppetclass)
+
+        host.environment.locations = [host.location]
+        host.environment.organizations = [host.organization]
+
+        lookup_key = FactoryBot.create(:puppetclass_lookup_key, :array, default_value: %w[a b],
+                                                                        override: true,
+                                                                        puppetclass: host.puppetclasses.first,
+                                                                        overrides: { "fqdn=#{host.fqdn}" => %w[c d] })
+        lookup_value = lookup_key.lookup_values.first
+
+        # sending exactly what the host form would send which is lookup_value.value_before_type_cast
+        lk_params = { 'lookup_values_attributes' => { lookup_key.id.to_s => { 'value' => lookup_value.value_before_type_cast,
+                                                                              'id' => lookup_value.id,
+                                                                              'lookup_key_id' => lookup_key.id,
+                                                                              '_destroy' => false } } }
+        params = {
+          host_id: host.id,
+          host: host.attributes.merge(lk_params),
+        }
+
+        # environment change calls puppetclass_parameters which caused the extra escaping
+        post :puppetclass_parameters, params: params, session: set_session_user, xhr: true
+
+        # if this was escaped during refresh_host the value in response.body after unescapeHTML would include "[\\\"c\\\",\\\"d\\\"]"
+        assert_includes CGI.unescapeHTML(response.body), '["c","d"]'
+      end
+    end
   end
 end
diff --git a/test/helpers/foreman_puppet_enc/hosts_and_hostgroups_helper_test.rb b/test/helpers/foreman_puppet_enc/hosts_and_hostgroups_helper_test.rb
new file mode 100644
index 00000000..7050611c
--- /dev/null
+++ b/test/helpers/foreman_puppet_enc/hosts_and_hostgroups_helper_test.rb
@@ -0,0 +1,60 @@
+require 'test_puppet_enc_helper'
+
+module ForemanPuppetEnc
+  class HostsAndHostgroupsHelperTest < ActionView::TestCase
+    include ::ApplicationHelper
+    include ::FormHelper
+    include ::HostsHelper
+
+    include HostsAndHostgroupsHelper
+
+    describe 'puppet environment field' do
+      setup do
+        @host = mock('host')
+        @host.stubs(:hostgroup)
+        @host.stubs(:id).returns(999)
+        @f = mock('f')
+        @f.stubs(:object).returns(@host)
+      end
+
+      test 'it adds new first level attributes' do
+        @f.expects(:collection_select).with do |*attrs|
+          select_options, html_options = extract_collection_options(attrs)
+          select_options[:test_select_option] == 'test_value1' &&
+            html_options[:test_html_option] == 'test_value2'
+        end
+
+        host_puppet_environment_field(@f, { test_select_option: 'test_value1' }, { test_html_option: 'test_value2' })
+      end
+
+      test 'it adds new data attributes' do
+        @f.expects(:collection_select).with do |*attrs|
+          select_options, html_options = extract_collection_options(attrs)
+          select_options[:test_select_option] == 'test_value1' &&
+            html_options[:data][:test] == 'test_value2'
+        end
+
+        host_puppet_environment_field(@f, { test_select_option: 'test_value1' }, { data: { test: 'test_value2' } })
+      end
+
+      test 'it overrides existing attributes' do
+        @f.expects(:collection_select).with do |*attrs|
+          html_options = attrs.pop
+          html_options[:data][:test] == 'some_test_value' &&
+            html_options[:data][:url] == '/test/url'
+        end.returns('')
+
+        html = host_puppet_environment_field(@f, { disable_button: false }, { data: { url: '/test/url', test: 'some_test_value' } })
+
+        assert_no_match(/btn/, html)
+      end
+    end
+
+    private
+
+    def extract_collection_options(attrs)
+      html_opts = attrs.pop
+      [attrs.pop, html_opts]
+    end
+  end
+end
diff --git a/test/integration/foreman_puppet_enc/host_js_test.rb b/test/integration/foreman_puppet_enc/host_js_test.rb
index 99c198d7..66a337a2 100644
--- a/test/integration/foreman_puppet_enc/host_js_test.rb
+++ b/test/integration/foreman_puppet_enc/host_js_test.rb
@@ -1,8 +1,317 @@
 require 'test_puppet_enc_helper'
 require 'integration_test_helper'
+require 'integration/shared/host_finders'
+require 'integration/shared/host_orchestration_stubs'
 
 module ForemanPuppetEnc
   class HostJSTest < IntegrationTestWithJavascript
+    include HostFinders
+    include HostOrchestrationStubs
+
+    let(:host) { FactoryBot.create(:host, :with_puppet, :managed) }
+    let(:org) { Organization.find_by(name: 'Organization 1') }
+    let(:loc) { Location.find_by(name: 'Location 1') }
+
+    describe 'new host page' do
+      test 'choosing a hostgroup overrides other host attributes' do
+        original_hostgroup = FactoryBot
+                             .create(:hostgroup, environment: FactoryBot.create(:environment))
+        overridden_hostgroup = FactoryBot
+                               .create(:hostgroup, environment: FactoryBot.create(:environment))
+
+        visit new_host_path
+        select2(original_hostgroup.name, from: 'host_hostgroup_id')
+        wait_for_ajax
+        click_on_inherit('environment')
+        select2(overridden_hostgroup.name, from: 'host_hostgroup_id')
+        assert page.find('#s2id_host_environment_id .select2-chosen').has_text? overridden_hostgroup.environment.name
+      end
+
+      test 'sets fields to "inherit" when hostgroup is selected' do
+        env1 = FactoryBot.create(:environment, organizations: [org], locations: [loc])
+        env2 = FactoryBot.create(:environment, organizations: [org], locations: [loc])
+        hg = FactoryBot.create(:hostgroup, environment: env2)
+        os = FactoryBot.create(:ubuntu14_10, :with_associations)
+        disable_orchestration
+        visit new_host_path
+
+        fill_in 'host_name', with: 'myhost1'
+        select2 'Organization 1', from: 'host_organization_id'
+        wait_for_ajax
+        select2 'Location 1', from: 'host_location_id'
+        wait_for_ajax
+        select2 env1.name, from: 'host_environment_id'
+        select2 hg.name, from: 'host_hostgroup_id'
+        wait_for_ajax
+
+        click_link 'Operating System'
+        select2 os.architectures.first.name, from: 'host_architecture_id'
+        select2 os.title, from: 'host_operatingsystem_id'
+        uncheck('host_build')
+
+        select2 os.media.first.name, from: 'host_medium_id'
+        select2 os.ptables.first.name, from: 'host_ptable_id'
+        fill_in 'host_root_pass', with: '12345678'
+
+        switch_form_tab_to_interfaces
+        click_button 'Edit'
+        select2 domains(:mydomain).name, from: 'host_interfaces_attributes_0_domain_id'
+        fill_in 'host_interfaces_attributes_0_mac', with: '00:11:11:11:11:11'
+        fill_in 'host_interfaces_attributes_0_ip', with: '2.3.4.44'
+
+        close_interfaces_modal
+
+        click_on_submit
+
+        host = Host::Managed.search_for('name ~ "myhost1"').first
+        assert_equal env2.name, host.environment.name
+      end
+
+      test 'saves correct values for inherited fields without hostgroup' do
+        env = FactoryBot.create(:environment, organizations: [org], locations: [loc])
+        os = FactoryBot.create(:ubuntu14_10, :with_associations)
+        Nic::Managed.any_instance.stubs(:dns_conflict_detected?).returns(true)
+        visit new_host_path
+
+        fill_in 'host_name', with: 'myhost1'
+        select2 'Organization 1', from: 'host_organization_id'
+        wait_for_ajax
+        select2 'Location 1', from: 'host_location_id'
+        wait_for_ajax
+        select2 env.name, from: 'host_environment_id'
+
+        click_link 'Operating System'
+        wait_for_ajax
+        select2 os.architectures.first.name, from: 'host_architecture_id'
+        select2 os.title, from: 'host_operatingsystem_id'
+        uncheck('host_build')
+        select2 os.media.first.name, from: 'host_medium_id'
+        select2 os.ptables.first.name, from: 'host_ptable_id'
+        fill_in 'host_root_pass', with: '12345678'
+
+        switch_form_tab_to_interfaces
+        click_button 'Edit'
+        select2 domains(:mydomain).name, from: 'host_interfaces_attributes_0_domain_id'
+        fill_in 'host_interfaces_attributes_0_mac', with: '00:11:11:11:11:11'
+        fill_in 'host_interfaces_attributes_0_ip', with: '1.1.1.1'
+        close_interfaces_modal
+        click_on_submit
+        find('#host-show') # wait for host details page
+
+        host = Host::Managed.search_for('name ~ "myhost1"').first
+        assert_equal env.name, host.environment.name
+      end
+    end
+
+    describe 'edit page' do
+      test 'environment is not inherited on edit' do
+        env1 = FactoryBot.create(:environment, organizations: [org], locations: [loc])
+        env2 = FactoryBot.create(:environment, organizations: [org], locations: [loc])
+        hg = FactoryBot.create(:hostgroup, environment: env2)
+        host = FactoryBot.create(:host, :with_puppet, hostgroup: hg)
+        visit edit_host_path(host)
+
+        select2 env1.name, from: 'host_environment_id'
+        click_on_submit
+
+        host.reload
+        assert_equal env1.name, host.environment.name
+      end
+
+      test 'choosing a hostgroup does not override other host attributes' do
+        original_hostgroup = FactoryBot
+                             .create(:hostgroup, environment: FactoryBot.create(:environment),
+                                                 puppet_proxy: FactoryBot.create(:puppet_smart_proxy))
+
+        # Make host inherit hostgroup environment
+        host.attributes = host.apply_inherited_attributes(
+          'hostgroup_id' => original_hostgroup.id
+        )
+        host.save
+
+        overridden_hostgroup = FactoryBot
+                               .create(:hostgroup, environment: FactoryBot.create(:environment))
+
+        visit edit_host_path(host)
+        select2(original_hostgroup.name, from: 'host_hostgroup_id')
+
+        assert_equal original_hostgroup.puppet_proxy.name, find('#s2id_host_puppet_proxy_id .select2-chosen').text
+
+        click_on_inherit('puppet_proxy')
+        select2(overridden_hostgroup.name, from: 'host_hostgroup_id')
+
+        assert find('#s2id_host_environment_id .select2-chosen').has_text? original_hostgroup.environment.name
+
+        # On host group change, the disabled select will be reset to an empty value - disabled select2 is invisible on chrome
+        assert find('#s2id_host_puppet_proxy_id .select2-chosen', visible: :all).has_text? ''
+      end
+
+      context 'has inherited Puppetclasses' do
+        test 'has the hostgroup inherited parameters visible' do
+          hostgroup = FactoryBot.create(:hostgroup, :with_puppetclass)
+          host = FactoryBot.create(:host, hostgroup: hostgroup, environment: hostgroup.environment)
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+
+          header_element = page.find('#puppet_enc_tab .panel h3 a')
+          assert header_element.text =~ /#{hostgroup.name}$/
+          header_element.click
+
+          class_element = page.find('#inherited_ids > li')
+          assert_equal hostgroup.puppetclasses.first.name, class_element.text
+        end
+      end
+
+      describe 'Puppetclass Params' do
+        let(:host) { FactoryBot.create(:host, :with_puppet, :with_puppetclass) }
+
+        test 'shows errors on invalid lookup values' do
+          lookup_key = FactoryBot.create(:puppetclass_lookup_key,
+            key_type: 'real', default_value: true, path: "fqdn\ncomment",
+            puppetclass: host.puppetclasses.first, overrides: { host.lookup_value_matcher => false })
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert page.has_no_selector?('#puppet_klasses_parameters td.has-error')
+
+          fill_in "host_lookup_values_attributes_#{lookup_key.id}_value", with: 'invalid'
+          click_button('Submit')
+          assert page.has_selector?('#puppet_klasses_parameters td.has-error')
+        end
+
+        test 'correctly show hash type overrides' do
+          FactoryBot.create(:puppetclass_lookup_key, :hash,
+            default_value: 'a: b', path: "fqdn\ncomment",
+            puppetclass: host.puppetclasses.first,
+            overrides: { host.lookup_value_matcher => 'a: c' })
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert_equal("a: c\n", puppetclass_params.find('textarea').value)
+        end
+
+        test 'class parameters and overrides are displayed correctly for booleans' do
+          lookup_key = FactoryBot.create(:puppetclass_lookup_key,
+            key_type: 'boolean', default_value: 'false', path: 'fqdn',
+            puppetclass: host.puppetclasses.first, overrides: { host.lookup_value_matcher => 'false' })
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert puppetclass_params.has_selector?("a[data-tag='remove']", visible: :visible)
+          assert puppetclass_params.has_selector?("a[data-tag='override']", visible: :hidden)
+          assert_equal('false', find("#s2id_host_lookup_values_attributes_#{lookup_key.id}_value .select2-chosen").text)
+          select2 'true', from: "host_lookup_values_attributes_#{lookup_key.id}_value"
+          click_on_submit
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert_equal('true', find("#s2id_host_lookup_values_attributes_#{lookup_key.id}_value .select2-chosen").text)
+        end
+
+        test 'class parameters and overrides are displayed correctly for strings' do
+          FactoryBot.create(:puppetclass_lookup_key, default_value: 'default', path: 'fqdn',
+                                                     puppetclass: host.puppetclasses.first, overrides: { host.lookup_value_matcher => 'hostOverride' })
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert_equal('hostOverride', puppetclass_params.find('textarea').value)
+          assert puppetclass_params.find('textarea:enabled')
+          puppetclass_params.find("a[data-tag='remove']").click
+          assert puppetclass_params.find('textarea:disabled')
+          click_on_submit
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert_equal('default', puppetclass_params.find('textarea').value)
+          assert puppetclass_params.find('textarea:disabled')
+          puppetclass_params.find("a[data-tag='override']").click
+          assert puppetclass_params.find('textarea:enabled')
+          puppetclass_params.find('textarea').set('userCustom')
+          click_on_submit
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert_equal('userCustom', puppetclass_params.find('textarea').value)
+          assert puppetclass_params.find('textarea:enabled')
+        end
+
+        test 'can override puppetclass lookup values' do
+          FactoryBot.create(:puppetclass_lookup_key, default_value: 'default', path: 'fqdn',
+                                                     puppetclass: host.puppetclasses.first, overrides: { host.lookup_value_matcher => 'hostOverride' })
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert puppetclass_params.has_selector?("a[data-tag='remove']", visible: :visible)
+          assert puppetclass_params.has_selector?("a[data-tag='override']", visible: :hidden)
+          assert_equal('hostOverride', puppetclass_params.find('textarea').value)
+          assert puppetclass_params.find('textarea:enabled')
+
+          puppetclass_params.find("a[data-tag='remove']").click
+          assert puppetclass_params.has_selector?("a[data-tag='remove']", visible: :hidden)
+          assert puppetclass_params.has_selector?("a[data-tag='override']", visible: :visible)
+          assert_equal('default', puppetclass_params.find('textarea').value)
+          assert puppetclass_params.find('textarea:disabled')
+
+          puppetclass_params.find("a[data-tag='override']").click
+          assert puppetclass_params.has_selector?("a[data-tag='remove']", visible: :visible)
+          assert puppetclass_params.has_selector?("a[data-tag='override']", visible: :hidden)
+          assert_equal('default', puppetclass_params.find('textarea').value)
+          assert puppetclass_params.find('textarea:enabled')
+        end
+
+        context 'with non-admin user' do
+          test 'user without edit_params permission can save host with params' do
+            FactoryBot.create(:puppetclass_lookup_key,
+              default_value: 'string1', path: "fqdn\ncomment",
+              puppetclass: host.puppetclasses.first,
+              overrides: { host.lookup_value_matcher => 'string2' })
+            user = FactoryBot.create(:user, :with_mail, roles: roles(:viewer, :edit_hosts))
+            assert_not user.can? 'edit_params'
+            set_request_user(user)
+            visit edit_host_path(host)
+            switch_form_tab('Puppet ENC')
+            assert puppetclass_params.find('textarea').disabled?
+            click_button('Submit')
+            assert page.has_link?('Edit')
+          end
+        end
+
+        test 'selecting domain updates puppetclass parameters' do
+          skip 'Needs PuppetInfo extracted properly' unless ForemanPuppetEnc.extracted_from_core?
+          disable_orchestration
+          domain = FactoryBot.create(:domain)
+          FactoryBot.create(:puppetclass_lookup_key, path: "fqdn\ndomain\ncomment",
+                                                     puppetclass: host.puppetclasses.first, default_value: 'default',
+                                                     overrides: { "domain=#{domain.name}" => 'domain' })
+
+          visit edit_host_path(host)
+          switch_form_tab('Puppet ENC')
+          assert_equal('default', puppetclass_params.find('textarea').value)
+
+          switch_form_tab_to_interfaces
+          table.first(:button, 'Edit').click
+
+          select2 domain.name, from: 'host_interfaces_attributes_0_domain_id'
+          modal.find(:button, 'Ok').click
+
+          switch_form_tab('Puppet ENC')
+          assert_equal 'domain', puppetclass_params.find('textarea').value
+        end
+      end
+    end
+
+    describe 'clone page' do
+      test 'clones lookup values' do
+        host = FactoryBot.create(:host, :with_puppetclass)
+        lookup_key = FactoryBot.create(:puppetclass_lookup_key, puppetclass: host.puppetclasses.first,
+                                                                path: "fqdn\ncomment",
+                                                                overrides: { host.lookup_value_matcher => 'abc' })
+        visit clone_host_path(host)
+        switch_form_tab('Puppet ENC')
+        a = page.find("#host_lookup_values_attributes_#{lookup_key.id}_value")
+        assert_equal 'abc', a.value
+      end
+    end
+
     describe 'hosts index multiple actions' do
       setup do
         @entries = Setting[:entries_per_page]
@@ -47,29 +356,16 @@ class HostJSTest < IntegrationTestWithJavascript
       end
     end
 
-    describe 'Puppet Classes tab' do
-      context 'has inherited Puppetclasses' do
-        setup do
-          @hostgroup = FactoryBot.create(:hostgroup, :with_puppetclass)
-          @host = FactoryBot.create(:host, hostgroup: @hostgroup, environment: @hostgroup.environment)
-
-          visit edit_host_path(@host)
-          page.find(:link, 'Puppet Classes', href: '#puppet_klasses').click
-        end
-
-        test 'it mentions the hostgroup by name in the tooltip' do
-          page.find('#puppet_klasses .panel h3 a').click
-          class_element = page.find('#inherited_ids>li')
+    private
 
-          assert_equal @hostgroup.puppetclasses.first.name, class_element.text
-        end
-
-        test 'it shows a header mentioning the hostgroup inherited from' do
-          header_element = page.find('#puppet_klasses .panel h3 a')
+    def puppetclass_params
+      page.find('#puppet_klasses_parameters_table')
+    end
 
-          assert header_element.text =~ /#{@hostgroup.name}$/
-        end
-      end
+    # TODO: unless ForemanPuppetEnc.extracted_from_core?
+    def switch_form_tab_to_interfaces
+      switch_form_tab('Interfaces')
+      disable_interface_modal_animation
     end
   end
 end
diff --git a/test/integration/foreman_puppet_enc/hostgroup_js_test.rb b/test/integration/foreman_puppet_enc/hostgroup_js_test.rb
index c57cf47b..307bfad6 100644
--- a/test/integration/foreman_puppet_enc/hostgroup_js_test.rb
+++ b/test/integration/foreman_puppet_enc/hostgroup_js_test.rb
@@ -4,57 +4,98 @@
 module ForemanPuppetEnc
   class HostJSTest < IntegrationTestWithJavascript
     let(:hostgroup) { FactoryBot.create(:hostgroup, :with_puppetclass) }
+    let(:environment) { FactoryBot.create(:environment) }
 
-    describe 'edit form' do
+    describe 'create new page' do
+      test 'create new page' do
+        environment
+        assert_new_button(hostgroups_path, 'Create Host Group', new_hostgroup_path)
+        fill_in 'hostgroup_name', with: 'staging'
+        select2 environment.name, from: 'hostgroup_environment_id'
+        assert_submit_button(hostgroups_path)
+        assert_equal environment.id,
+          Hostgroup.find_by(name: 'staging').environment_id,
+          'Hostgroup not created or environment not set'
+      end
+    end
+
+    describe 'edit page' do
       setup do
         @another_puppetclass = FactoryBot.create(:puppetclass)
       end
 
-      context 'puppet classes are not available in the environment' do
+      describe 'changing the environment' do
         setup do
-          hostgroup.puppetclasses << @another_puppetclass
-          visit edit_hostgroup_path(hostgroup)
+          @another_environment = environment
+          @hostgroup = FactoryBot.create(:hostgroup, :with_puppetclass)
+          visit hostgroups_path
+          click_link @hostgroup.name
         end
 
-        describe 'Puppet classes tab' do
-          test 'it shows a warning' do
-            click_link 'Puppet Classes'
-            wait_for_ajax
-
-            assert page.has_selector?('#puppetclasses_unavailable_warning')
-          end
+        test 'preserves the puppetclasses' do
+          puppetclasses = @hostgroup.puppetclasses.all
 
-          test 'it marks selected classes as unavailable' do
-            click_link 'Puppet Classes'
-            wait_for_ajax
+          select2 @another_environment.name, from: 'hostgroup_environment_id'
+          assert_submit_button(hostgroups_path)
 
-            assert page.has_selector?('.selected_puppetclass.unavailable')
-          end
+          assert_equal puppetclasses, @hostgroup.puppetclasses.all
         end
       end
-    end
 
-    describe 'Form Puppet Classes tab' do
       context 'has inherited Puppetclasses' do
-        setup do
-          @child_hostgroup = FactoryBot.create(:hostgroup, parent: hostgroup)
+        test 'has the parent group inherited parameters visible' do
+          child_hostgroup = FactoryBot.create(:hostgroup, parent: hostgroup)
 
-          visit edit_hostgroup_path(@child_hostgroup)
-          page.find(:link, 'Puppet Classes', href: '#puppet_klasses').click
-        end
+          visit edit_hostgroup_path(child_hostgroup)
+          switch_form_tab('Puppet ENC')
 
-        test 'it mentions the parent hostgroup by name in the tooltip' do
-          page.find('#puppet_klasses .panel h3 a').click
-          class_element = page.find('#inherited_ids>li')
+          header_element = page.find('#puppet_enc_tab .panel h3 a')
+          assert header_element.text =~ /#{hostgroup.name}$/
+          header_element.click
 
+          class_element = page.find('#inherited_ids > li')
           assert_equal hostgroup.puppetclasses.first.name, class_element.text
         end
+      end
 
-        test 'it shows a header mentioning the hostgroup inherited from' do
-          header_element = page.find('#puppet_klasses .panel h3 a')
-          assert header_element.text =~ /#{hostgroup.name}$/
+      test 'shows errors on invalid lookup values' do
+        lookup_key = FactoryBot.create(:puppetclass_lookup_key, :integer,
+          path: 'hostgroup', puppetclass: hostgroup.puppetclasses.first,
+          overrides: { hostgroup.lookup_value_matcher => 2 })
+
+        visit edit_hostgroup_path(hostgroup)
+        switch_form_tab('Puppet ENC')
+        assert page.has_no_selector?('#puppet_klasses_parameters .input-group.has-error')
+        fill_in "hostgroup_lookup_values_attributes_#{lookup_key.id}_value", with: 'invalid'
+        click_button('Submit')
+        assert page.has_selector?('#puppet_klasses_parameters td.has-error')
+      end
+
+      context 'puppet classes are not available in the environment' do
+        test 'it shows a warning and marks as unavailable' do
+          hostgroup.puppetclasses << @another_puppetclass
+          visit edit_hostgroup_path(hostgroup)
+
+          switch_form_tab('Puppet ENC')
+
+          assert page.has_selector?('#puppetclasses_unavailable_warning')
+          assert page.has_selector?('.selected_puppetclass.unavailable')
         end
       end
     end
+
+    describe 'clone page' do
+      test 'clones lookup values' do
+        group = FactoryBot.create(:hostgroup, :with_puppetclass)
+        lookup_key = FactoryBot.create(:puppetclass_lookup_key, path: "hostgroup\ncomment",
+                                                                puppetclass: group.puppetclasses.first,
+                                                                overrides: { group.lookup_value_matcher => 'abc' })
+
+        visit clone_hostgroup_path(group)
+        switch_form_tab('Puppet ENC')
+        a = page.find("#hostgroup_lookup_values_attributes_#{lookup_key.id}_value")
+        assert_equal 'abc', a.value
+      end
+    end
   end
 end
diff --git a/webpack/__mocks__/foremanReact/components/Layout/LayoutActions.js b/webpack/__mocks__/foremanReact/components/Layout/LayoutActions.js
new file mode 100644
index 00000000..597e0575
--- /dev/null
+++ b/webpack/__mocks__/foremanReact/components/Layout/LayoutActions.js
@@ -0,0 +1,2 @@
+export const showLoading = () => jest.fn();
+export const hideLoading = () => jest.fn();
diff --git a/webpack/__mocks__/foremanReact/redux/index.js b/webpack/__mocks__/foremanReact/redux/index.js
new file mode 100644
index 00000000..d1bd5727
--- /dev/null
+++ b/webpack/__mocks__/foremanReact/redux/index.js
@@ -0,0 +1 @@
+export const store = { dispatch: jest.fn() };
diff --git a/webpack/fills_index.js b/webpack/fills_index.js
index 3ab36475..282645ad 100644
--- a/webpack/fills_index.js
+++ b/webpack/fills_index.js
@@ -1,15 +1,30 @@
-// This example for extanding foreman-core's component via slot&fill
+import $ from 'jquery';
 
-/*
-import React from 'react';
-import { addGlobalFill } from 'foremanReact/components/common/Fill/GlobalFill';
+import * as classEditor from './src/foreman_class_edit';
+import * as hostForm from './src/foreman_puppet_host_form';
 
-addGlobalFill('slotId', 'fillId', <SomeComponent key="some-key" />, 300);
+window.tfm = Object.assign(window.tfm || {}, {
+  classEditor,
+  puppetEnc: {
+    hostForm,
+  },
+});
 
-addGlobalFill(
-  'slotId',
-  'fillId',
-  { someProp: 'this is an override prop' },
-  300
-);
-*/
+// TODO: the checkForUnavailablePuppetclasses is very nasty
+$(document)
+  .on('change', '.hostgroup-select', evt => {
+    const form = $('form.host-form')[0];
+    if (form && form.dataset.id) hostForm.updatePuppetclasses(evt.target);
+  })
+  .on('change', '.interface_domain', evt => {
+    hostForm.reloadPuppetclassParams();
+  })
+  .on('change', '.host-architecture-os-select', evt => {
+    hostForm.reloadPuppetclassParams();
+  })
+  .on('ContentLoad', evt => {
+    hostForm.checkForUnavailablePuppetclasses();
+  });
+$(window).on('load', evt => {
+  hostForm.checkForUnavailablePuppetclasses();
+});
diff --git a/webpack/index.js b/webpack/index.js
index de205c74..ff5c6f98 100644
--- a/webpack/index.js
+++ b/webpack/index.js
@@ -5,9 +5,6 @@ import componentRegistry from 'foremanReact/components/componentRegistry';
 import { registerReducer } from 'foremanReact/common/MountingService';
 import reducers from './src/reducers';
 import ForemanPuppetEnc from './src/ForemanPuppetEnc';
-import * as classEditor from './src/foreman_class_edit.js';
-
-Object.assign(window.tfm, { classEditor });
 
 // register reducers
 Object.entries(reducers).forEach(([key, reducer]) =>
diff --git a/webpack/src/foreman_class_edit.js b/webpack/src/foreman_class_edit.js
index 970c4775..183f0c23 100644
--- a/webpack/src/foreman_class_edit.js
+++ b/webpack/src/foreman_class_edit.js
@@ -46,16 +46,16 @@ export function addPuppetClass(item) {
     `<input id='${type}_puppetclass_ids_' name='${type}[puppetclass_ids][]' type='hidden' value=${id}>`
   );
 
-  const link = content.children('a');
+  const linkIcon = content.children('a.glyphicon');
   const links = content.find('a');
 
   links.attr('onclick', 'tfm.classEditor.removePuppetClass(this)');
   links.attr(
     'data-original-title',
-    sprintf(__('Click to remove %s'), link.data('class-name'))
+    sprintf(__('Click to remove %s'), linkIcon.data('class-name'))
   );
   links.tooltip();
-  link.removeClass('glyphicon-plus-sign').addClass('glyphicon-minus-sign');
+  linkIcon.removeClass('glyphicon-plus-sign').addClass('glyphicon-minus-sign');
 
   $('#selected_classes').append(content);
 
@@ -64,8 +64,8 @@ export function addPuppetClass(item) {
     .addClass('selected-marker')
     .hide();
   findElementsForRemoveIcon($(`#puppetclass_${id}`));
-  // trigger load_puppet_class_parameters in host_edit.js which is fired by custom event handler called 'AddedClass'
-  $(document.body).trigger('AddedClass', link);
+
+  window.tfm.puppetEnc.hostForm.loadPuppetClassParameters(linkIcon);
 }
 
 function addGroupPuppetClass(item) {
@@ -78,12 +78,12 @@ function addGroupPuppetClass(item) {
   content.children('span').tooltip();
   content.val('');
 
-  const link = content.children('a');
+  const linkIcon = content.children('a.glyphicon');
   const links = content.find('a');
   links.attr('onclick', '');
   links.attr('data-original-title', __('belongs to config group'));
   links.tooltip();
-  link.removeClass('glyphicon-plus-sign');
+  linkIcon.removeClass('glyphicon-plus-sign');
 
   $('#selected_classes').append(content);
 
@@ -91,9 +91,9 @@ function addGroupPuppetClass(item) {
   $(`#puppetclass_${id}`)
     .addClass('selected-marker')
     .hide();
+  findElementsForRemoveIcon($(`#puppetclass_${id}`));
 
-  // trigger load_puppet_class_parameters in host_edit.js which is fired by custom event handler called 'AddedClass'
-  $(document.body).trigger('AddedClass', link);
+  window.tfm.puppetEnc.hostForm.loadPuppetClassParameters(linkIcon);
 }
 
 export function removePuppetClass(item) {
@@ -115,9 +115,9 @@ export function removePuppetClass(item) {
   $(`#selected_puppetclass_${id}`).remove();
   $(`#puppetclass_${id}_params_loading`).remove();
   $(`[id^="puppetclass_${id}_params\\["]`).remove();
-  $('#params-tab').removeClass('tab-error');
-  if ($('#params').find('.form-group.error').length > 0)
-    $('#params-tab').addClass('tab-error');
+  $('a[href="#puppet_enc_tab"]').removeClass('tab-error');
+  if ($('#puppet_enc_tab').find('.form-group.error').length > 0)
+    $('a[href="#puppet_enc_tab"]').addClass('tab-error');
 
   return false;
 }
@@ -140,7 +140,7 @@ export function addConfigGroup(item) {
   $(`#config_group_${id}`)
     .addClass('selected-marker')
     .hide();
-  const link = content.children('a');
+  const link = content.children('a.glyphicon');
   const links = content.find('a');
   link.attr('onclick', 'tfm.classEditor.removeConfigGroup(this)');
   link.attr('data-original-title', __('Click to remove config group'));
@@ -159,13 +159,13 @@ export function addConfigGroup(item) {
 
   $.each(puppetclassIds, (index, puppetclassId) => {
     const pc = $(`li#puppetclass_${puppetclassId}`);
-    const pcLink = $(`a[data-class-id='${puppetclassId}']`);
+    const pcLink = $(`#puppetclass_${puppetclassId} > a.glyphicon`);
     if (
       pcLink.length > 0 &&
       pc.length > 0 &&
       $.inArray(puppetclassId, inheritedIds) === -1
     ) {
-      if (!($(`#selected_puppetclass_${puppetclassId}`).length > 0)) {
+      if ($(`#selected_puppetclass_${puppetclassId}`).length <= 0) {
         addGroupPuppetClass(pcLink);
       }
     }
@@ -187,9 +187,11 @@ export function removeConfigGroup(item) {
 
   $.each(puppetclassIds, (index, puppetclassId) => {
     const pc = $(`#selected_puppetclass_${puppetclassId}`);
-    const pcLink = $(`a[data-class-id='${puppetclassId}']`);
+    const pcLink = $(`#puppetclass_${puppetclassId} > a.glyphicon`);
+    // do not remove if manually added - having minus icon
     if (
       pcLink.length > 0 &&
+      !pcLink.hasClass('glyphicon-minus-sign') &&
       pc.length > 0 &&
       $.inArray(puppetclassId, inheritedIds) === -1
     ) {
@@ -208,13 +210,15 @@ function findElementsForRemoveIcon(element) {
 export function expandClassList(clickedElement, toggleSelector) {
   $(toggleSelector).fadeToggle();
   $(clickedElement)
-    .find('i')
+    .find('.glyphicon')
     .toggleClass('glyphicon-plus glyphicon-minus');
   removeIconIfEmpty($(clickedElement), toggleSelector);
 }
 
 function removeIconIfEmpty(element, ulId) {
   if ($(ulId).children(':visible').length === 0) {
-    element.find('i').hide();
+    element.find('.glyphicon').hide();
+  } else {
+    element.find('.glyphicon').show();
   }
 }
diff --git a/webpack/src/foreman_puppet_host_form.js b/webpack/src/foreman_puppet_host_form.js
new file mode 100644
index 00000000..df64c16e
--- /dev/null
+++ b/webpack/src/foreman_puppet_host_form.js
@@ -0,0 +1,113 @@
+/* eslint-disable jquery/no-ajax */
+/* eslint-disable jquery/no-class */
+/* eslint-disable jquery/no-html */
+/* eslint-disable jquery/no-data */
+
+import $ from 'jquery';
+
+import { translate as __ } from 'foremanReact/common/I18n';
+import store from 'foremanReact/redux';
+import * as LayoutActions from 'foremanReact/components/Layout/LayoutActions';
+
+export function loadPuppetClassParameters(item) {
+  const id = $(item).data('class-id');
+  // host_id could be either host.id OR hostgroup.id depending on which form
+  const hostId = $('form.hostresource-form').data('id');
+  if (!hostId) return; // it is not host nor hostgroup form - probably config_group
+  if ($(`#puppetclass_${id}_params_loading`).length > 0) return; // already loading
+  if ($(`[id^="#puppetclass_${id}_params\\["]`).length > 0) return; // already loaded
+  const url = $(item).data('url');
+  let data = window.serializeForm().replace('method=patch', 'method=post');
+  if (url.match('hostgroups')) {
+    data += `&hostgroup_id=${hostId}`;
+  } else {
+    data += `&host_id=${hostId}`;
+  }
+
+  if (!url) return; // no parameters
+  const spinner = window.spinner_placeholder(__('Loading parameters...'));
+  const placeholder = $(
+    `<tr id="puppetclass_${id}_params_loading"><td colspan="5">${spinner}</td></tr>`
+  );
+  $('#puppet_klasses_parameters_table').append(placeholder);
+  $.ajax({
+    type: 'post',
+    url,
+    data,
+    success: (result, textstatus, xhr) => {
+      const params = $(result);
+      placeholder.replaceWith(params);
+      params.find('a[rel="popover"]').popover();
+      if (params.find('.error').length > 0)
+        $('#puppet_enc_tab').addClass('tab-error');
+    },
+  });
+}
+
+export function updatePuppetclasses(element) {
+  const hostId = $('form.hostresource-form').data('id');
+  const url = $('#puppet_klasses_reload_url').data('url');
+  let data = window.serializeForm().replace('method=patch', 'method=post');
+
+  if (element.value === '') return;
+  if (url.match('hostgroups')) {
+    data += `&hostgroup_id=${hostId}`;
+  } else {
+    data += `&host_id=${hostId}`;
+  }
+
+  store.dispatch(LayoutActions.showLoading());
+  window.tfm.tools.showSpinner();
+  $.ajax({
+    type: 'post',
+    url,
+    data,
+    success: request => {
+      $('#puppet_enc_tab').html(request);
+      window.tfm.tools.activateTooltips();
+      checkForUnavailablePuppetclasses();
+    },
+    complete: () => {
+      store.dispatch(LayoutActions.hideLoading());
+      // TODO do only the necessary - we know what we are loading here
+      window.reloadOnAjaxComplete(element);
+    },
+  });
+}
+
+export function reloadPuppetclassParams() {
+  const hostId = $('form.hostresource-form').data('id');
+  const url = $('#puppet_klasses_parameters').data('url');
+  let data = window.serializeForm().replace('method=patch', 'method=post');
+  if (url.match('hostgroups')) {
+    data += `&hostgroup_id=${hostId}`;
+  } else {
+    data += `&host_id=${hostId}`;
+  }
+  window.load_with_placeholder('puppet_klasses_parameters_table', url, data);
+}
+
+export function checkForUnavailablePuppetclasses() {
+  const unavailableClasses = $(
+    '#puppet_enc_tab #selected_classes .unavailable'
+  );
+  const puppetEncTab = $('#puppet_enc_tab');
+  const tab = puppetEncTab
+    .closest('form')
+    .find('.nav-tabs a[href="#puppet_enc_tab"]');
+  const warningMessage = __(
+    'Some Puppet Classes are unavailable in the selected environment'
+  );
+  const warning = `<div class="alert alert-warning" id="puppetclasses_unavailable_warning">
+      <span class="pficon pficon-warning-triangle-o"></span>
+      ${warningMessage}
+    </span>`;
+
+  if (unavailableClasses.size() > 0) {
+    tab.prepend('<span class="pficon pficon-warning-triangle-o"></span> ');
+    puppetEncTab.prepend(warning);
+  } else {
+    puppetEncTab.find('#puppetclasses_unavailable_warning').remove();
+    tab.find('.pficon-warning-triangle-o').remove();
+  }
+}
diff --git a/webpack/src/foreman_puppet_host_form.test.js b/webpack/src/foreman_puppet_host_form.test.js
new file mode 100644
index 00000000..5c4bbf9d
--- /dev/null
+++ b/webpack/src/foreman_puppet_host_form.test.js
@@ -0,0 +1,65 @@
+/* eslint-disable jquery/no-size */
+
+import $ from 'jquery';
+
+import { checkForUnavailablePuppetclasses } from './foreman_puppet_host_form';
+
+jest.unmock('jquery');
+jest.unmock('./foreman_puppet_host_form');
+
+describe('checkForUnavailablePuppetclasses', () => {
+  beforeEach(() => {
+    document.body.innerHTML = `<div>
+        <ul class="nav-tabs">
+          <li><a href="#puppet_enc_tab" data-toggle="tab">Puppet Classes</a></li>
+        </ul>
+        <div class="tab-content">
+          <form>
+            <div class="tab-pane active" id="hostgroup">
+                <div class="form-group">
+                  <div>
+                    <input id="hostgroup_environment_id"/>
+                  </div>
+                  <span class="help-block"></span>
+                </div>
+            </div>
+            <div class="tab-pane" id="puppet_enc_tab">
+              <div id="selected_classes"></div>
+            </div>
+          </form>
+        </div>
+      </div>`;
+  });
+
+  it('adds a warning if an unavailable class is found', () => {
+    $('#selected_classes').append(
+      '<li class="unavailable">Unavailable Class</li>'
+    );
+
+    checkForUnavailablePuppetclasses();
+    expect($('#puppetclasses_unavailable_warning').size()).toBe(1);
+  });
+
+  it('does not add a warning if no unavailable classes are found', () => {
+    $('#hostgroup .help-block').empty();
+    $('#selected_classes').empty();
+
+    checkForUnavailablePuppetclasses();
+    expect(
+      $('#hostgroup .help-block')
+        .first()
+        .children()
+        .size()
+    ).toBe(0);
+  });
+
+  it('adds a warning sign to the tab if unavailable classes are found', () => {
+    $('#selected_classes').append(
+      '<li class="unavailable">Unavailable Class</li>'
+    );
+    checkForUnavailablePuppetclasses();
+    setTimeout(() => {
+      expect($('a .pficon').size()).toBe(1);
+    }, 100);
+  });
+});