Understanding before and after_filter - ruby-on-rails-3

I have the following code right after my controller class declaration
before_filter :load_form, :except => [:create, :update, :delete]
after_filter :load_form, :only => [:create, :update, :delete]
def load_form
#severities = Severity.all
#severity = Severity.new
end
I get the list of severities when the page loads just fine, meaning that the before_filter is working. However after calling a method such as create the list of severities always comes back as nil. I think I am probably just missing some fundamental thing about filters. Can anyone help me understand why the after_filter does not work?

If you were expecting to see variables in your view that were assigned in your 'after' filter, that won't work because the filter is not executed until after your view has been completely processed.

Related

Issue with helper_methods from views rails

I have a very frustrating issue.
I can't call any helper method from my views in rails.This is what I have:
ApplicationController.rb
class ApplicationController < ActionController::Base
protect_from_forgery
def current_user
#current_user ||= User.find(session[:user_id]) if session[:user_id]
end
helper_method :current_user
helper_method :all
end
/app/views/welcome/_navi_bar.haml:
%ul.nav.nav-pills.pull-right
%li.pull-right
- if current_user
%a.btn-small{"data-toggle" => "modal", :href => log_out_path, :role => "button"}
%i.icon-user.icon-white
%strong
Log Out
- else
%a.btn-small{"data-toggle" => "modal", :href => "#LoginBox", :role => "button"}
%i.icon-user.icon-white
%strong
Login
This is what I get as error:
undefined local variable or method `current_user' for #<#<Class:0x007ff0a0544668>:0x007ff0a05414b8>
I really don't get what the problem is. Please help !
You have written your code in application controller instead of application helper
That is the reason why your method is not getting called
if you want to check if current user is logged in or not
you may just use before filter in application controller and call the method
whenever you dont need to check the method add skip before filter in that place

How to invoke a rails sweeper in this scenario?

As you can see from code below. I am caching the show action. I also have the following method in the show action View.create_for(#song).
I would like to make it so, when View.create_for(#song) is called, it clears out the respective cache.
How would I go about this? Do I have to manually invoke the rails sweeper in the View model? If so, how?
My controller:
class SongsController < ApplicationController
caches_action :show, :cache_path => (proc do
song_path(params[:id], :user_id => user_signed_in? ? current_user.id : nil)
end)
# I tried with the following line, but this is not what I want. I only want to call the sweeper when `View.create_for(#song)` is called:
# cache_sweeper :views_sweeper, :only => [:show]
def show
#song = Song.find(params[:id])
View.create_for(#song)
end
end
My Sweeper:
class SongsSweeper < ActionController::Caching::Sweeper
observe Song
def after_save(song)
expire_fragment(/songs\/#{song.id}\/.*?/)
end
end
I think you should be referring to the songs_sweeper, not the views_sweeper:
cache_sweeper :songs_sweeper, :only => [:show]
I'm not sure of your requirements, but you could also be more specific in your SongsSweeper by changing after_save to after_create:
class SongsSweeper < ActionController::Caching::Sweeper
observe Song
def after_create(song)
expire_fragment(/songs\/#{song.id}\/.*?/)
end
end

Rails 3 recursive polymorphic comments model, how to do redirect to top-most parent

I'm still earning my stripes in Rails and have ran into a problem I can use some help on. I'm building an app that has various models (stories, photos, artwork, etc.) that a user can comment on, as well as the comments themselves. I have 98-99% of the functionality working but am stuck on getting the redirect to redirect to the top-most parent (a story, photo, etc.) after the comment has been created.
My comment model look like this:
# /app/models/comment.rb
class Comment < ActiveRecord::Base
belongs_to :commentable, :polymorphic => true
has_many :comments, :as => :commentable
end
...I have several models that a user can comment on, for example a story model:
# /app/models/story.rb
class Story < ActiveRecord::Base
has_many :comments, :as => :commentable
end
My comments controller looks like this at this point:
# /app/controllers/comments_controller.rb
class CommentsController < ApplicationController
def index
#commentable = find_commentable
#comments = #commentable.comments
end
def new
#commentable = find_commentable
end
def create
#commentable = find_commentable
#comment = #commentable.comments.build(params[:comment])
if #comment.save
redirect_to :back
else
render :action => 'new'
end
end
protected
def find_commentable
params.each do |name, value|
if name =~ /(.+)_id$/
return $1.classify.constantize.find(value)
end
end
nil
end
end
...And of course my routes look like this:
# /config/routes.rb
resources :comments do
resources :comments
end
resources :stories do
resources :comments
end
The particular line I need to change is the redirect_to :back line (everything else, the polymorphism, the recursion of comments, etc. works fine). The current code works as intended when a user is commenting on a story but it's not ideal when a user is commenting on a comment because the form for that functionality is not on the story "show" page (perhaps it needs to be?).
What I have tried to do (and what I suspect the solution might be) is a method that finds the parent object and recurses when that object is a comment. My previous attempts at doing this has not been clean at all and I have yet to get a working prototype working.
I used this railscasts episode to base the majority of my code but the redirect_to :id => nil doesn't work for me as the create comment method is somehow called and it results in a NilClass error when it attempts to build comments (perhaps something is wrong with my routing as I don't see how the index action would call create?).
So Rails experts, what am I doing wrong? What do I need to do here to get this working? I feel like I'm 99% there but that last 1% is driving me crazy.
Thanks in advance...
OK i had to read this a couple times...
#comment.commentable
would return an instance of Story or whatever object that did the comment.
Solved this...It's probably not the cleanest but it works:
I first added a method in comments controller...
def get_master
#parent = #comment.commentable
if #parent.respond_to?('commentable_type')
#comment = #parent
get_master
else
return #parent
end
end
Then I changed my redirect_to to call this method in the create controller.
The key was understanding that #object.respond_to? was what I needed to do check if a method is defined.
Here's a full example of how it works: http://t.co/N6WIGzuW

Posting with Nested Resources

I have nested my resources (see below) and when I try to create a new entity, I get the following error. Does anyone know why I'm getting this error and how to solve it?
undefined method `applications' for nil:NilClass
resources careers do
resources applications
end
Within the 'Applications' controller I have:
before_filter [[:authenticate, :except => :new], :load_career]
def create
# The following line is where the error originates
#application = #career.applications.new(params[:application])
respond_to do |format|
...
end
end
private
def load_career
#career = Career.find(params[:career_id])
end
The Career and Application models have has_many :applications and belongs_to :career respectively.
And the '*_create_applications' migration has a career_id field.
I have never seen before_filters defined that way. I just tried it in Rails 3 and it doesn't seem to do anything. I would give each callback it's own before_filter call:
before_filter :authenticate, :except => :new
before_filter :load_career

NoMethodError - undefined method

I'm having problems displaying data from a separate controller. I have a number of users, each with many pages. I've followed this tutorial with a few minor adjustments.
The error that keeps appearing is:
NoMethodError in SitesController#show
undefined method `page' for #<ActionDispatch::Request:0x00000102452d30>
My routes.rb is as follows:
devise_for :users
resources :users, :only => [:index, :show] do
resources :pages, :shallow => true
end
match '/' => 'sites#show', :constraints => { :subdomain => /.+/ }
root :to => "home#index"
And I have a sites controller:
class SitesController < ApplicationController
def show
#site = Site.find_by_name!(request.page)
end
end
I've also tried:
def show
#site = Site.find_by_name!(params[:site])
end
Which gives a different error.
Am totally stuck trying to figure this out!
Looking forward to your assistance.
Bob
The problem is here: request.page
The request object is of the class ActionDispatch::Request, which does not have a page method.
To track down errors like this, you can try either looking at the docs or messing around in the debugger.
Try running your controller with --debugger enabled.
If you are running Ruby 1.8, install the ruby-debug gem.
If you are running Ruby 1.9, install the ruby-debug19 gem.
Add a debugger call here:
class SitesController < ApplicationController
def show
debugger
#site = Site.find_by_name!(request.page)
end
end
Run your server with the --debugger option.
See what p request.page does. I bet it will have an "undefined method" error, just you see when you try to view that controller action.
If you do a p request.class you can find out what class the object is, and then look up the docs to see how to use it.