Question

Basically I have a follow button and when click the page refreshes and I show an unfollow button in place. Below is the code I use to render the particular form needed:

follow_forms partial:

<% unless current_user?(@user) %>
  <% if current_user.following?(@user) %>
    <%= render 'relationships/partials/unfollow' %>
  <% else %>
    <%= render 'relationships/partials/follow' %>
  <% end %>
<% end %>

Any I changed the form to an ajax form because I don’t want the page refresh and on success of the form submission I’d like to replace the follow button/form with an unfollow button/form. This isn’t straight forward because only 1 form shows at a time so I can’t use my jquery selector to find this form anyway.

What I decided to do was create a new action that renders the follow_form partial this way the appropriate form will be available for me to manipulate with my jquery selector.

The new action:

class RelationshipsController < ApplicationController

  def get_follow_form
    respond_to do |format|
      format.html { render :partial => 'relationships/partials/follow_form_ajax' }
    end
  end
end

The problem now is that I don’t have access to the @user instance variable. That doesn’t matter to much because I can get the user who was just followed via the jquery success data then pass that as data in the new ajax call to get_follow_form_url and then pass that info into the partial as a local variable.

I still have an issue with the @user instance variable not being available. Which brings me to my question.

How can I make another value be used if the instance variable isn’t nil/doesn’t exist?

The form for following:

<%= form_for current_user.relationships.build(:followed_id => @user.id), :remote => true do |f| %>
<%= f.hidden_field :followed_id %>
<%= f.submit "Follow", :class => 'followButton' %>
<% end %>

Can I do something like this

 :followed_id => @user.id <-if this doesn't exist use this-> user.id 

There are other ways around this like creating new partials that are only used for this whole situation or creating some messy if statements but I feel like creating duplicate forms should be my very very very last option.

I look forward to you solutions thanks

Kind regards

Answer 1

There’s a very simple way to do this, assuming you have your ‘fallback’ ID:

:followed_id => @user.present? ? @user.id : fallback_id