Rails警告不起作用

Question

I am trying to alert a user if they are logged in or not to an app. Here is my sessions destroy action:

  def destroy
    session[:user_id] = nil
    redirect_to root_url, alert: "Logged out!"
  end

Pretty strait forward. One somebody clicks the logout button, I would like an alert to pop u saying "Logged out!".

It isn't showing up, but I also believe I am missing something in the view. What do I have to do in the views for this to show?

Answer 1

Your view template should conditionally render a flash message if one is in the session. The following snippet will display all alert flash messages:

<% if flash[:alert] %>
    <div class="alert"><%= flash[:alert] %></div>
<% end %>

UPDATE :

If, alternatively, you would like to render out any flash message type (eg, alert , notice , warning , etc.), you can use the following snippet to iterate through any and all of the flash messages in your session:

<% flash.each do |key, value| %>
    <div class="<%= key %>"><%= value %></div>
<% end %>

Assuming you utilize more than one flash message type, this latter approach is more dynamic and requires less code to handle than handling each flash message type individually.