Let flash messages disappear in the same page in rails

Question

I want to make the flash message disappear after a few seconds. So I use these codes:

$(function() {
  $('.alert').slideUp(1500);
});

.alert is the bootstrap class I add to the flash message.

And my app achieved user login/logout function only through omniauth. (with facebook and google plus) The login/logout codes listed in the end.

When I log in, the flash message disappeared like what I thought. But when I log out, the flash didn't disappear.

But if I use these codes, this function will work correctly. (but slightly different than what I want)

$(function() {
  setInterval(function(){
    $('.alert').slideUp(500);
  }, 1000);
});

login/out codes:

class SessionsController < ApplicationController
  def create
    auth_data = request.env['omniauth.auth']
    auth = Authorization.find_by( provider: auth_data['provider'], uid: auth_data['uid'] ) 
    user = auth.nil? ? User.create_with_omniauth(auth_data) : auth.user
    session[:user_id] = user.id
    if !user.email
      redirect_to edit_user_path(user), :alert => "Please enter your email address."
    else
      redirect_to root_url, :notice => "Signed in!"
    end
  end

  def destroy
    reset_session
    redirect_to root_url, :notice => "Signed out!"
  end

  def new
  end

  def failure
    redirect_to root_url, :alert => "Authentication error: #{params[:message].humanize}"
  end
end

Answer 1

try this

$(function() {
  setTimeout(function(){
    $('.alert').slideUp(500);
  }, 1000);
});