feat: user flash notices instead of explicit notification banners

app/controllers/organisation_relationships_controller.rb

@@ -53,7 +53,8 @@ class OrganisationRelationshipsController < ApplicationController
       return
     end
     create!(child_organisation_id:, parent_organisation_id:, relationship_type:)
-    redirect_to housing_providers_organisation_path(related_organisation_id:)
+    flash[:notice] = "#{Organisation.find(related_organisation_id).name} is now one of #{current_user.data_coordinator? ? 'your' : "this organisation's"} housing providers"
+    redirect_to housing_providers_organisation_path
   end
 
   def create_managing_agent
@@ -84,7 +85,8 @@ class OrganisationRelationshipsController < ApplicationController
   def delete_housing_provider
     organisation_relationship_to_remove = OrganisationRelationship.find_by!(child_organisation_id: @organisation.id, parent_organisation_id: target_organisation_id, relationship_type: OrganisationRelationship::OWNING)
     organisation_relationship_to_remove.destroy!
-    redirect_to housing_providers_organisation_path(removed_organisation_id: target_organisation_id)
+    flash[:notice] = "#{Organisation.find(target_organisation_id).name} is no longer one of #{current_user.data_coordinator? ? 'your' : "this organisation's"} housing providers"
+    redirect_to housing_providers_organisation_path
   end
 
 private

app/views/organisation_relationships/housing_providers.html.erb

@@ -1,45 +1,8 @@
 <% item_label = format_label(@pagy.count, "housing providers") %>
-
-<% if current_user.data_coordinator? %>
-  <% if params["related_organisation_id"] %>
-    <%= govuk_notification_banner(
-          title_text: "Success",
-          success: true, title_heading_level: 3,
-          title_id: "swanky-notifications"
-        ) do |notification_banner|
-          notification_banner.heading(text: "#{Organisation.find(params['related_organisation_id']).name} is now one of your housing providers")
-        end %>
-  <% elsif params["removed_organisation_id"] %>
-    <%= govuk_notification_banner(
-          title_text: "Success",
-          success: true, title_heading_level: 3,
-          title_id: "swanky-notifications"
-        ) do |notification_banner|
-          notification_banner.heading(text: "#{Organisation.find(params['removed_organisation_id']).name} is no longer one of your housing providers")
-        end %>
-  <% end %>
-<% end %>
 <% if current_user.support? %>
   <%= render partial: "organisations/headings", locals: { main: @organisation.name, sub: nil } %>
   <%= render SubNavigationComponent.new(items: secondary_items(request.path, @organisation.id)) %>
   <h2 class="govuk-visually-hidden">Housing Providers</h2>
-  <% if params["related_organisation_id"] %>
-    <%= govuk_notification_banner(
-          title_text: "Success",
-          success: true, title_heading_level: 3,
-          title_id: "swanky-notifications"
-        ) do |notification_banner|
-          notification_banner.heading(text: "#{Organisation.find(params['related_organisation_id']).name} is now one of this organisation's housing providers")
-        end %>
-  <% elsif params["removed_organisation_id"] %>
-    <%= govuk_notification_banner(
-          title_text: "Success",
-          success: true, title_heading_level: 3,
-          title_id: "swanky-notifications"
-        ) do |notification_banner|
-          notification_banner.heading(text: "#{Organisation.find(params['removed_organisation_id']).name} is no longer one of this organisation's housing providers")
-        end %>
-  <% end %>
   <p class="govuk-body">This organisation can submit logs for its housing providers.</p>
   <% if @total_count == 0 %>
     <p class="govuk-body">This organisation does not currently have any housing providers.</p>