Rails - Change boolean value on link click - ruby-on-rails

Question

In my app I have user notifications where the user gets notified for certain actions. These notifications are being shown in a dropdown from the navbar (like Facebook or S.O.). All of the notifications have a boolean attribute called :read and are default set to false. I'm using bootstrap with the dropdowns (in case that helps).
I want to create a method where when the user clicks to open the dropdown, all of their unread notifications become read.
Here is what I have so far for the method.
def read_notifications
PublicActivity::Activity.where(recipient_id: current_user).where(read: false).update_all(:read => true)
end
This updates all of the current user's notifications to :read => true when the method is called. In the view here is what I had so far for the dropdown link.
<%= link_to read_notifications_path, :class => "dropdown-toggle notifications_icon", :'data-toggle' => "dropdown", :controller => "application", :action => "read_notifications", :method => :post do %><% end %>
and the routes.rb I had this.
match "/read" => "application#read_notifications", :as => "read_notifications", via: 'post'
Now I know what I have is wrong, but even so when I click the link it does switch all of the user's notifications to read, it just acts also as a link (duh) and goes to a different page.
As you know, the link on a bootstrap dropdown is "#".
Does anyone know how I can set this up properly where when the user clicks the notification link in the navbar, ALL it does is open the dropdown and change the boolean value to true for all notifications.
I know this is possible, I just haven't been able to figure it out yet.
Thanks for taking a look at it.
EDIT
JS file
$(".notifications_icon").on("click", function(){
$.post("/read", function(data){
$('.notification_badge').text("");
});
});
View
<%= link_to "#", :class => "dropdown-toggle notifications_icon", :'data-toggle' => "dropdown" do %>
<span class="notification_badge"><%= find_unread_notifications_count(current_user) %></span>
<% end %>
This is Posting to the /read to read all of the notifications but it's not updating the count

Answer 1

You want a dash of unobtrusive JS. For example, SO has a class js-inbox-button that, when clicked, triggers updates on unread counts (both client and server). I won't dig into their JS source, but it's fairly simple to build.
You seem to already have a relevant class (notifications_icon), though you might want to use something else. When the link is clicked, use jquery $.post.
$(".notifications_icon").on("click", function(){
$.post("/read", function(data){
// remove unread count
$('.notification_badge').text('');
});
});
Now this is a very basic implementation. Couple of suggestions:
Only make requests when necessary (check for unread count on page first)
Use a data attribute on the link to pass /read path. That way you can still use your path helpers instead of hardcoding a path.
Store the above JS in a separate file (unobtrusive)

Answer 2

AJAX.
By adding remote: true you're starting with AJAX. Now the call goes to your path, and nothing happens! yay!
You want something to happen, though. So in your controller (I wouldn't do it in the application_controller, if I were you... activities_controller.rb maybe?):
controllers/activities_controller.rb
def read_notifications
PublicActivity::Activity.where(recipient_id: current_user).where(read: false).update_all(:read => true)
respond_to do |format|
format.js
end
end
You're on your way to Asynchronous loading! Now you need a js file to match it. So, since you've already moved this action to the activites, in your view, you'll have a new js.erb file to create (notice that it's in the same folder in the views as the controller name, and the file is named after the action):
views/activities/read_notifications.js.erb
$('#your_menu_div').html("<%= j render partial: 'activities/notifications' %>");
Now you create a partial (views/activities/_notifications.html.erb) that gets rendered into your pulldown menu.
Clear as mud?