Introduce flash for matchmatching groups

app/controllers/matchmaking_groups_controller.rb

@@ -10,7 +10,13 @@ def new
   end
 
   def create
-    MatchmakingGroup.create(group_params.merge(slack_user_id: @current_user.slack_user_id))
+    if MatchmakingGroup.exists?(name: group_params[:name])
+      flash[:error] = "Group already exists"
+    else
+      MatchmakingGroup.create(group_params.merge(slack_user_id: @current_user.slack_user_id))
+      flash[:notice] = "Group created"
+    end
+
     redirect_to matchmaking_groups_path
   end
 
@@ -21,7 +27,15 @@ def edit
 
   def update
     @group = MatchmakingGroup.find_by(id: params[:id])
-    @group.update(group_params)
+
+    if @group.name != group_params[:name] && MatchmakingGroup.exists?(name: group_params[:name])
+      flash[:error] = "Other group already exists with that name"
+    else
+      @group = MatchmakingGroup.find_by(id: params[:id])
+      @group.update(group_params)
+
+      flash[:notice] = "Group updated"
+    end
     redirect_to matchmaking_groups_path
   end
 

app/views/matchmaking_groups/index.html.erb

@@ -1,6 +1,10 @@
 <div class="w-full">
-  <% if notice.present? %>
-    <p class="py-2 px-3 bg-green-50 mb-5 text-green-500 font-medium inline-block" id="notice"><%= notice %></p>
+  <% if flash[:notice].present? %>
+    <p class="py-2 px-3 bg-green-50 mb-5 text-green-500 font-medium inline-block" id="notice"><%= flash[:notice] %></p>
+  <% end %>
+
+  <% if flash[:error].present? %>
+    <p class="py-2 px-3 bg-red-50 mb-5 text-red-500 font-medium inline-block" id="error"><%= flash[:error] %></p>
   <% end %>
 
   <div class="flex justify-between items-center">