Using Ajax requests in rails - ruby-on-rails

Question

Hi I want to build an app using Ajax. Whenever a user visits an other user page he can add him as a friend by clicking add friend link. This is my current code in users/show page
<% if current_user.friend?(current_user,#user) %>
<%= link_to "Unfriend", relation_path(#relation), user: #user, method: :delete, data: { confirm: 'Are you sure? This action cannot be undone' }, class: 'btn btn-default' %>
<% elsif #user != current_user %>
<%= link_to "Add Friend", friendships_path(:friend_id => user), :method => :post, class: 'btn btn-default' %>
<% end %>
My code in relations controller
def create
if params[:friend_id]
if Relation.where(user_id: current_user.id, friend_id: params[:friend_id]).present?
redirect_to user_path(params[:friend_id]), notice: "Already friends"
elsif current_user.id == params[:friend_id]
redirect_to user_path(params[:friend_id]), alert: "Invalid Request"
else
#relation = current_user.relations.new(friend_id: params[:friend_id], subject: Constants::Subject::MAKE)
if #relation.save
friend = User.find(params[:friend_id])
friend.relations.create!(friend_id: current_user.id, subject: Constants::Subject::MAKE)
redirect_to user_path(params[:friend_id]), notice: "Added as friend"
else
redirect_to user_path(params[:friend_id]), alert: "Could not add as friend"
end
end
else
redirect_to current_user, notice: "Invalid Request"
end
end
I am following this Ryan Bates rails casts. How can I make the link_to add friend Ajax request instead of html request. The current code is working fine. I want to add Ajax functionality for this. I have seen a lot of questions but I could not understand what exactly to be done. Please help.

Answer 1

Add remote: true to the link_to tag. There is more information in the guides abou rails and ajax. You will need a respond_to block to handle the response.
Start with adding remote: true and use the console to see the call being made and what the response is. Then you can figure out how to handle the response.
<%= link_to "Add Friend", friendships_path(:friend_id => user), :method => :post, remote: true, class: 'btn btn-default' %>

Answer 2

Please take a look:
Move your buttons into a partial
Render it inside a div with ID = "actions"
Update your controller response with format js
Add field create.js.erb which render your buttons by javascript
Render your flashes box by javascript by the same way (if needed)
your view_file.erb
<div id="actions">
<%= render "views/realtions/actions", relation: #relation, friend: #user %>
</div>
views/realtions/_actions.html.erb
<% if current_user.friend?(current_user, friend) %>
<%= link_to "Unfriend", relation_path(relation), user: friend, method: :delete, remote: true, data: { confirm: 'Are you sure? This action cannot be undone' }, class: 'btn btn-default' %>
<% elsif friend != current_user %>
<%= link_to "Add Friend", friendships_path(friend_id: friend.id), method: :post, remote: true, class: 'btn btn-default' %>
<% end %>
views/realtions/create.js.erb
<%- if #friend.present? %>
$("#actions").html("<%= j render 'views/realtions/actions', relation: #relation, friend: #friend %>")
<%- end %>
// render your flashes to DOM here!
controllers/relations_controller.rb
def create
if params[:friend_id]
#friend = User.find(params[:friend_id])
if Relation.where(user_id: current_user.id, friend_id: #friend.id).present?
flash[:notice] = "Already friends"
elsif current_user.id == params[:friend_id]
flash[:error] = "Invalid Request"
else
#relation = current_user.relations.new(friend_id: params[:friend_id], subject: Constants::Subject::MAKE)
if #relation.save
#friend.relations.create!(friend_id: current_user.id, subject: Constants::Subject::MAKE)
flash[:notice] = "Added as friend"
else
flash[:error] = "Could not add as friend"
end
end
else
flash[:notice] = "Invalid Request"
end
respond_to do |format|
format.js
end
end
Hope this help