Preserving form submission through log in / sign up in Rails - ruby-on-rails

Say I have a site like this (generic Q&A site) in Rails and I wanted this "ask" page w/ a text box to be the first page a user sees, even if he's not logged in. He enters a question, and on the 'new' method I check that he's not logged in, and bounced him to /session/new, where he can either log in or create a new account. Question is, how do I (and what is the best way to) preserve that question that he initially asked all through this process?

I'm understanding the flow of action described in the question to be
user is presented with a form
user is redirected to log in page on submit
user is redirected back to form on successful log in
repopulate form on load (Question asks how to do this step)
user finally submits their form.
With steps 2-4 omitted if the user is logged in.
I'm sorry, but I see your question more as a symptom of an underlying UI issue than a rails question.
If only logged in users can post questions, then why display the text box?
If a user is going to have log in any way, why not get that out of the way first. An even better solution is to integrate the log in and form.
Something like this in the view:
<% form_for :question do |form| %>
<% unless logged_in? %>
<% fields_for :session do |session_form|%>
<%= session_form.label :login %>
<%= session_form.text_field :login %>
<%= session_form.label :password %>
<%= session_form.password_field :password %>
<%end%>
<%end%>
<%= form.text_area :question %>
<%end%>
And in the controller
def new
...
unless params[:session].nil?
self.current_user = User.authenticate(params[:session][:login], params[:session][:password])
end
if logged_in?
flash[:notice] = "Logged in successfully"
else
flash[:error] = "Incorrect username and or password."
end
if logged_in? && #question.save
.... process successful entry
else
... process unsuccessful entry
end
end
Edit: Mohamad's raises the question of reusing this pattern across multiple controllers and forms. So the answer was updated to address reuse of this pattern.
To simplify this for reuse, you could put this block in a helper function that is referenced in the before_filter for actions that require it.
def login
unless params[:session].nil?
self.current_user = User.authenticate(params[:session][:login], params[:session][:password])
if logged_in?
flash[:notice] = "Logged in successfully"
else
flash[:error] = "Incorrect username and or password."
end
end
end
as in:
before_filter :login => :only [:new , :edit, :update, :delete]
On the view side, it shouldn't be too hard to construct a new variant of form_for that embeds the session parameters. Maybe form_for_with_session?
As for handling an unsuccessful response, I would suggest helper function that takes a block of code. Sorry I don't have time to write out or test one for you.

You keep it in the session. So after logging in, when the user goes back to asking his question, you see there's already something in session.
And you can directly display it.

def create
if current_user # Implement this method in your auth framework
#question = Question.new(params[:question] || session.delete[:question])
# (the usual stuff you'd do to save)
else
session[:question] = params[:question]
redirect_to :controller => :sessions, :action => "new"
end
end
Then, after your user creation and authentication stuff is all done in your login action, just make sure you POST back to this create action if session[:question] is defined.

Related

Ruby No Method Error on a Model for Current User when Logged Out

I'm building a rails app that has a lot of things that change based on whether or not the user has completed certain quizzes. Everything works fine when a user is logged in, but I just tried logging out and I got a NoMethodErroron this line of code:
<% if current_user.per_quiz.nil? %>
Basically, if the user has completed per_quiz they go to one page (the edit view), if they haven't they go to a different page (the new view). The only thing that changed was the fact that I logged out, so I can only assume that is what caused the error. Do I need to add some kind of if statement to account for a state in which no user is logged in? How should I fix this error in accordance with Ruby best practices?
You just need to check to see if current_user is set before checking per_quiz. You can handle checking for the login state easily in a view by querying current_user.nil?:
<% if !current_user %>
<p> You must be logged in to do anything useful. Please go login</p>
<% elsif !current_user.per_quiz %>
<p>Cool quiz stuff goes here...</p>
<% else %>
What you probably really want is to have a logged out user go elsewhere, such as the home page or signin page. To do that, you need to do a couple of simple things to your controller. I'm going to assume that the controller is called 'QuizzesController' since you hadn't included your controller code in the question.
Here's how to do it:
class QuizzesController < ApplicationController
# Other devise authentication logic goes here...
before_action :authorize_user!
# Your actions go here...
private
def authorize_user!
if !current_user
redirect_to '/', notice: "You must be logged in to access to this page"
end
end
end
What this does is install a "before_action" handler that will check that the user is logged in before letting them do anything in this controller. If they are not logged in, you can redirect them wherever you wish.
Note that sometimes, only certain actions need this kind of treatment. In that case, you can use an :only or :except option to specify which action(s) are or are not handled. It looks like this:
before_action :authorize_user!, only: [ :new, :edit, :create ]
or like this:
before_action :authorize_user!, except: :list
This will give you greater flexibility in managing the authorization part of the equation, where devise handles the authentication part.
That's because current_user is nil when no user logged in. And if you will cal some method on nil it will throw NoMethodError.
I assume that have code you provided in the view. So, you can check if user is logged in.
<% if user_signed_in? %>
# do smth with user quizzes
<% else %>
# do something else
<% end %>
But the best way is to use before filter in the controller and not allow to anonymous to see that page.
Here is the example application with Rails and devise. https://github.com/RailsApps/rails-devise
Hope that helps.
I'm not sure if this is the "correct" Ruby way to do this, but the way I eventually found was to change it to an if/elsif/else statement:
<% if current_user.nil? %>
...
<% elsif current_user.bal_quiz.nil? %>
...
<% else %>
...
<% end %>
Probably should have figured this out before I posted the question, but I was (and still am) interested to see if there's a better or "more Ruby" way of doing this.

How to pass information from one controller to another via view rails

I am working on a reservation project and after login I want to pass the current user information from the Sessions Controller to a Reservations Controller via a home page. How can I do that? I have been following Michael Hartl's Rails Tutorial for the login. Here's what I have tried in the create section of the Sessions Controller
render home_path :local_variables[:id => user_id]
and in the home_path(users#home)
<%= link_to new_reservation_path(:user_id => :id) %>
but it shows me an undefined method error. My Reservation model has a user_id column.I am confused regarding this matter. What should I do?
render home_path :local_variables[:id => user_id]
Seems weird to me to pass locals that way (don't even know if it's possible, never seen locals used outside of rendering views/partials).
I think the best way is to redirect instead and set the user in the sessions once they have been logged in successfully, so in your login action:
user = User.find_by_email(params[:user][:email]) # or however you are finding the person trying to login
session[:user] = user
redirect_to home_path
then in users#home
#user = session[:user]
and finally, in the view:
<%= link_to new_reservation_path(:user_id => #user.id) %>
EDIT
Actually, probably not a good idea to store an object in the session, instead of
session[:user] = user
You could try:
session[:user_id] = user.id
and then to find the user:
#user = User.find(session[:user_id])
If you still get an undefined error then it's probably because the user is nil (unless the User model actually has no id attribute, which would be strange) so there might be an issue with the login part, it's hard to say without knowing what that looks like.
If you need the logged in user on every page, you could abstract the functionality out into the application controller:
before_filter :check_user
def check_user
#user = User.find(session[:user_id]) if session[:user_id]
end
Then, you can use the #user instance variable anywhere in your app.

Why won't debug work in this situation?

I'm using the gem called omniauth-facebook, with which I succeeded at implementing facebook login auth.
It looks fine but it won't pass data of the whole object to the view. It just says nil.
It should show an array of things when using 'debug' or 'inspect'. It shows the content of session[:name] fine somehow.
Controller
class SessionsController < ApplicationController
def create
#auth = request.env["omniauth.auth"]
session[:oauth_token] = #auth.credentials.token
session[:username] = #auth.extra.raw_info.username
session[:name] = #auth.extra.raw_info.name
redirect_to bookd_url, :notice => "Signed in!"
end
end
View
<% if signed_in? %>
<%= #auth.inspect %>
<%= debug #auth %><br />
<%= session[:name] %>
<% end %>
Output HTML
nil
---
...
John
Your create controller action does a redirect. After the redirect, the process will start from scratch, and #auth will no longer be defined. If you render the view at this point, #auth will be nil. This is your problem.
You need to think about what you are trying to do here. You set an #auth variable from the authentication details in the initial request. You then use this to set some data in the session, which records who is logged in for example. Then, on the next page, where the user is logged in, you want to look at #auth. This doesn't really make sense: once you've authenticated a user, all you need to care about is remembering which user is currently logged in. You don't need to store details about HOW they logged in, and in fact you probably shouldn't.
You should instead be doing something like this:
#in ApplicationController, protected section
protected
def current_user
if #current_user
return #current_user
elsif session[:username]
#current_user = User.find_by_username(session[:username])
return #current_user
end
end
This will allow you to write current_user in your controller and view code, to access the user who authenticated, originally, which is the whole reason for logging someone in and keeping them logged in.

Not sending a variable to another controller

I have a small problem:
I am trying to send a variable from controller 1 to controller 2 and then send it back to controller 1. Here is the logic:
In order to start making a new model, the user has to sign in.
Guest users must also have access to the path of the new model.
If not logged in, guest users have to be redirected to sign in.
Once logged in, users have to go back to the path they previously tried to access.
I decided to pass the type of the model to the log in screen and then pass it back to the new model action.
The variable type usually comes from the route, so upon redirecting to the login screen, I just pass it over.
businesses_controller.rb:
before_filter :require_login
def require_login
unless current_user
redirect_to signin_path( :type => params[:type])
end
end
When I get redirected, the variable gets passed into my url - so far, so good:
/signin?type=ccompany
The problem comes when I try to grab the variable from the URL and use its value to redirect the successfully logged in user back to where he tried to go to:
sessions_controller.rb:
class SessionsController < ApplicationController
before_filter :initialize_type , :only => [:new , :create]
def new
end
def create
user = User.find_by(email: params[:session][:email].downcase)
if user && user.authenticate(params[:session][:password])
sign_in user
if defined?(#type)
redirect_to send("new_#{#type}_path")
else
redirect_back_or user
end
else
flash.now[:error] = t('sign.invalid')
render 'new'
end
end
def destroy
sign_out
redirect_to root_url
end
private
def initialize_type
#type = params[:type]
end
end
When I put the #type variable into my view, its value renders without problems. But when I try to log in, this is the error I get:
undefined method `new__path' for #<SessionsController:0x007f76189d42f8>
I also tried
redirect_to :controller => "businesses" , :action => "new" , :type => params[:type]
But the type symbol passes with no key. I also tried putting a variable there, still doesn't work.
So far, it has only worked when I just write down a string that matches the path, but that is not what I need. I need to pass the value of the params[:type] hash. I've put the value of the variable in the view and it's all good, but when I try to pass it into a function, its value somehow 'disappears'.
How can I make this work?
Problem is:
if defined?(:type)
it always returns true, as a symbol is always defined. What you want is:
if defined?(#type)
however this might add 'unintentional feature' to your code, as nil is well defined in ruby. You should do:
if #type
NOTE:
I need to pass the value of the :type symbol. - symbol has no value. Variables do have values, symbol is a symbol and it is its own value.
After understanding the question:
The above still holds.
You cannot pass instance variable from one action to another. For each request rails instantiate new controller instance and all instance variables are lost. There are number of ways to pass it though.
Create hidden field in your form to hold the value. You need to keep in mind that its value can be overwritten by any internet user with a minimal knowledge of how internet works.
In your new action simple write the value into a session and read it in you create action. Since session is either stored server side or stored in encrypted cookie, there is very small chance anyone can temper with it.
Ok, I found a workaround.It's a bit clumsy and may cause security issues, but it works. I forced the variable to pass as a session parameter.
I put the received variable as a hidden field in the new session form:
<%= form_for(:session , url: sessions_path ) do |f| %>
<%= f.label :email , t('session.email') %>
<%= f.text_field :email %>
<%= f.label :password , t('session.password') %>
<%= f.password_field :password%>
<%= f.hidden_field :val , value: #type %>
##type is set in the before filter as a variable passed from another controller
Then, upon submit, I just catched the parameter and put it into its place:
if user && user.authenticate(params[:session][:password])
sign_in user
if defined?(#type)
params.require(:session).permit(:val)
#type = params[:session][:val]
redirect_to send("new_#{#type}_path")
else
redirect_back_or user
end
else
flash.now[:error] = t('sign.invalid')
render 'new'
end
end
Now the function works properly. Unfortunately, I have to use the view as a "conduit" that passes a variable. I would be really happy if somebody writes a helper method for this or a better workaround.
Cheers.

Prompt a user to login after he takes a certain action

One thing you can do on my rap lyric explanation site is "like" explanations (once you're logged in):
http://dl.getdropbox.com/u/2792776/screenshots/2010-01-17_1645.png
I'd like to show the "Like" links to users who aren't logged in, and then, when a non-logged in user clicks "Like", show him a lightbox with a "Login or Register" form (like Digg / Reddit)
http://dl.getdropbox.com/u/2792776/screenshots/2010-01-17_1650.png
What's the best way to accomplish this?
Currently I'm using this approach:
Clicking "Like" POSTs to /annotations/:id/vote (the POST body indicates whether the user is liking or "unliking").
The vote Annotation controller action has a require_user before_filter that looks like this:
def require_user
unless current_user
store_desired_location
flash[:notice] = "You'll need to login or register to do that"
redirect_to login_path # map.login '/login', :controller => 'user_sessions', :action => 'new'
return false
end
end
user_sessions#new looks like this:
def new
#user_session = UserSession.new
respond_to do |format|
format.html {}
format.js {
render :layout => false
}
end
end
The problem is that the redirect doesn't seem to work correctly over javascript:
http://dl.getdropbox.com/u/2792776/screenshots/2010-01-17_1700.png
How do I get this to redirect correctly?
Also, is this the right general approach? Another thought I had was to attach a different handler to the "Like" links in javascript when there was no logged in user (but I don't think this method scales well to other actions that I'd like to handle the same way)
There's a few problems to overcome here.
Browsers in general do not allow redirecting to a POST request.
redirect_to doesn't preserve format without additional input.
Store location does not preserve form data.
All these problems can be solved by eliminating redirects.
Here is how I've handed it in the past:
Instead of redirecting in required_user, render. If a before filter redirects or renders the pending action is cancelled. (No need to return false either). Unfortunately going this route blurs controller boundaries. But allows for simple html fallback, and lends its self to DRYness.
The high level view of the new work flow will be:
Request to annotations#vote (POST)
required_user filter fails
render new session
submit login information and original POST data back to annotations#vote (POST)
new filter in vote captures session information and logs in. vote proceeds as expected. If login fails return to 3.
annotations#vote redirects/renders as it should
Start by reworking the require_user to render the user_sessions#new template.
def require_user
unless current_user
flash[:notice] = "You'll need to login or register to do that"
#user_session ||= UserSession.new
respond_to do |format|
format.html {render :template => 'user_sessions/new'}
format.js {
render :template => 'user_sessions/new', :layout => false
}
end
end
end
The #user_session ||= UserSession.new ensures we can return validation errors to the form.
Now we've got to beef up your user_session#new template so that it can remember the action. Also if you plan on using lightboxes, this should be a partial rendered rendered by relevant RJS or the new.html.erb.
First we create a partial to create hidden fields preserving the POST data that would have been lost in a redirect:
<% if params[:controller] == "annotations" %>
<% content_for :old_form do %>
<%= hidden_field_tag "annotation[song_id]", params[:annotation][:song_id] %>
<%= hidden_field_tag "annotation[vote]", params[:annotation][:vote] %>
<% end %>
<% end %>
Then render that partial in the login partial that will occupy your lightbox:
<%= render :partial => vote_form_replica %>
<% url = params[:controller] == "user_sessions ? user_sessions_url : {} %>
<% form_tag #user_session, :url => url do |f| %>
<%= yield :old_form %>
<%= f.label :user_name %>
<%= f.text_field :user_name %>
<%= f.label :password %>
<%= f.password_field :password %>
<%= submit_tag %>
<%end%>
The empty hash for url in the form_tag looks like an error, but isn't. It ensures that the form data is posted to the url that rendered the form. Which at this point should be annotations/:id/vote
Now for the new filter to login. Essentially it will be doing what ever UserSessionsController#create does without the render/redirect. The following is copied from the RESTful authentication plugin.
def authenticate
self.current_user = User.authenticate(params[:login], params[:password])
if logged_in?
if params[:remember_me] == "1"
current_user.remember_me unless current_user.remember_token?
cookies[:auth_token] = { :value => self.current_user.remember_token,
:expires => self.current_user.remember_token_expires_at }
end
end
end
All that's left is to make sure the filter order is right.
before_filter :authenticate, :require_user, :only => :vote
N.B.: You're probably not going to use this version of require_user without this version of authenticate so it makes sense to combine them into a single filter.
And that's it. The way this has been set up allows for robust DRY easily reuseable code. By placing the new filters into ApplicationController they're available in any controller. From this point, adding this functionality to any other controllers/actions takes only 3 simple steps:
Create a new partial modelled after the vote_form_replica partial.
Add the corresponding render statement to the new session template.
Apply the filters to your actions.
I would approach this in the way you describe at the bottom of your question. Before displaying the page initially, check if the user is logged in. If they are, the "Like" links should use their normal behavior. If not, bind a click event to show the register/login panel. There's nothing about this that can't be reused. In fact, we use this exact method at my job. Any user action that requires authentication either follows its normal behavior or pops up a generic login panel depending on login state at the time the page loads.

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