render a partial on ajax:success in coffeescript in rails 5 - ruby-on-rails

Question

I am trying to render a partial after ajax call using coffee script but could not make it.
Controller which is called on AJAX request
def unfollow
#user = User.find(params[:follow][:followed_id])
current_user.unfollow!(#user)
render json: {result: "success"}
end
partial: User/follow.html.erb
<div id="follow_button">
<%=form_for(:follow,url: follow_users_path,remote:true) do |f| %>
<%= f.hidden_field :followed_id, value: #user.id %>
<%= f.submit "Follow", id: "Follow_button", class: "btn btn-primary" %>
<% end %>
</div>
Ajax:success function
$ ->
$('#unfollow_button').on "ajax:success", (e,data,status,xhr) ->
$('#follow_unfollow_button').html("<%= escape_javascript( render partial: 'users/follow') %>")
HTML which is on That place
<div id="unfollow_button">
<%=form_for(:follow,url: unfollow_users_path,remote:true) do |f| %>
<%= f.hidden_field :followed_id, value: #user.id %>
<%= f.submit "Unfollow", id: "unfollow_button", class: "btn btn-primary" %>
<% end %>
</div>
I am not getting any value from the server I just want to render it when ajax success. But it render like this
<%= escape_javascript( render partial: 'users/follow') %>
How to solve this? what am I missing?

Answer 1

Yeah you can't render an erb partial inside javascript from a json response like that. Here's how to fix
1) remove this line from the controller
render json: {result: "success"}
2) In views/users/ create a file called unfollow.js.coffee with the following code
$('#follow_unfollow_button').html("<%= j render('users/follow') %>")
3) You no longer need to bind to ajax success function so delete this code completely from wherever you had it
$ ->
$('#unfollow_button').on "ajax:success", (e,data,status,xhr) ->
$('#follow_unfollow_button').html("<%= escape_javascript( render partial: 'users/follow') %>")

Answer 2

Don't try to render it from the coffeescript in this case. Instead, render the result from controller and return that as data to ajax.
1) Change controller method to
def unfollow
#user = User.find(params[:follow][:followed_id])
current_user.unfollow!(#user)
render 'users/follow', :layout => false
end
2) Change JS function to
$ ->
$('#unfollow_button').on "ajax:success", (e,data,status,xhr) ->
$('#follow_unfollow_button').html(data)
As your controller will return something (and not an error), the ajax:success will fire up and instead of trying to render it in JS/coffeescript, just render it in controller and that way, you also don't need to render something just for the sake of returning information to client.