added JS for following/unfollowing

app/assets/javascripts/application.js.erb.coffee

@@ -72,7 +72,6 @@ $(document).on "click", "button[name=ib-answer]", ->
       btn.button "reset"
       $("textarea[name=ib-answer][data-id=#{iid}]").removeAttr "readonly"
 
-# TODO
 $(document).on "click", "button[name=ab-destroy]", ->
   btn = $(this)
   btn.button "loading"
@@ -92,6 +91,49 @@ $(document).on "click", "button[name=ab-destroy]", ->
     complete: (jqxhr, status) ->
       btn.button "reset"
 
+$(document).on "click", "button[name=user-action]", ->
+  btn = $(this)
+  btn.button "loading"
+  target = btn[0].dataset.target
+  action = btn[0].dataset.action
+  count = Number($("h4.entry-text#follower-count").html())
+
+  target_url = switch action
+    when 'follow'
+      count++
+      '/ajax/create_friend'
+    when 'unfollow'
+      count--
+      '/ajax/destroy_friend'
+
+  success = false
+
+  $.ajax
+    url: target_url
+    type: 'POST'
+    data:
+      screen_name: target
+    success: (data, status, jqxhr) ->
+      success = data.success
+      if data.success
+        $("h4.entry-text#follower-count").html(count)
+      showNotification data.message, data.success
+    error: (jqxhr, status, error) ->
+      console.log jqxhr, status, error
+      showNotification "An error occurred, a developer should check the console for details", false
+    complete: (jqxhr, status) ->
+      btn.button "reset"
+      if success
+        switch action
+          when 'follow'
+            btn[0].dataset.action = 'unfollow'
+            btn.attr 'class', 'btn btn-default btn-block'
+            btn.html 'Unfollow'
+          when 'unfollow'
+            btn[0].dataset.action = 'follow'
+            btn.attr 'class', 'btn btn-primary btn-block'
+            btn.html 'Follow'
+
 $(document).on "click", "button#create-account", ->
   Turbolinks.visit "/sign_up"