undefined method paypal_url in Rails -

i have piece of code in rails,

def create   @registration = registration.new(registration_params)   if @registration.save     redirect_to @registration.paypal_url(registration_path(@registration))   else     render :new   end end 

i took tutorial. need in line:

@registration.paypal_url(registration_path(@registration)) 

now, own controller, feed_controller, where

def create   @feed = feed.new(check_params) end 

in view erb file put:

@feed.paypal_url(feed_path(@feed)) 

in feed.rb (model):

def paypal_url(return_path)   values = {     business: "merchant@gotealeaf.com",     cmd: "_xclick",     upload: 1,     return: "#{rails.application.secrets.app_host}#{return_path}",     invoice: id,     amount: course.price,     item_name: course.name,     item_number: course.id,     quantity: '1'   }   "#{rails.application.secrets.paypal_host}/cgi-bin/webscr?" + values.to_query end 

rake routes:

feed        /:locale/feed(.:format)                     feed#index feed#create     post       /:locale/feed/create(.:format) feed#new        feed_new        /:locale/feed/new(.:format) feed#destroy    feed_destroy        /:locale/feed/destroy(.:format) feed#edit      feed_edit        /:locale/feed/edit(.:format) feed#update    feed_update        /:locale/feed/update(.:format)  

but prints next error:

undefined method `paypal_url' <#feed::activerecord_relation:0x007fee24f5fc98>

how can fix it? problem?

update

def index   @current_user_is = current_user.email   session[:email] = @current_user_is   session[:id] = current_user.id    unless (current_user.member.present?)     @member = member.new(:user_id => current_user.id)     @member.save()     redirect_to '/feed'   else     @new_feed = feed.new     @feed = feed.where(:member_id => current_user.member.id)     @category = category.all     render 'home/uploads'   end end 

simply use def self.paypal_url(return_path) instead of def paypal_url(return_path).

explanation

you ran problem defining class method instead of instance method, there's other posts discussing this.

the basic difference is, when defining:

def self.get_some_url   # code return url of instance end 

you can desired url of objects, in view:

<% @feeds.each |feed| %>   <%= feeds.get_some_url %> <% end %> 

now calling feed.get_some_url on class make no sense. url of thousands call?

but there lot of use class methods (where define method without self did)

def get_top_5   # code return top 5 viewed feeds end 

since has nothing single instance, define entire class. leading call: feed.get_top_5, makes sense.

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the second problem not understanding difference between where & find, this post out that.