How to prevent actions at specific date and time? - ruby-on-rails

I would like to allow the users to 'create' and 'update' their submissions (bets) until a specific date and time at which point their bets are final (can no longer be created or updated). This process would repeat each week.
I'm fairly new to Rails and I'm not sure if there is a term for this or what to search for.
Can anyone point me in the right direction?

Probably the easiest way to achieve this is just to add a before_filter (Rails 3.x) or before_action (Rails 4.x) to your controller. You can do so like this:
Assume you have submissions_controller.rb with create/update actions like so - add a before filter that will only apply to the create and update actions. You can then implement a private method in the controller to redirect the user back to your root_path or elsewhere and give a flash message as to why.
class PagesController < ApplicationController
before_filter :check_if_bets_are_final, :only => [:create, :update]
def create
...
end
def update
...
end
private
def check_if_bets_are_final
if Time.now >= Time.new(2014, 02, 20)
flash[:error] = "You can no longer modify or submit new bets!"
redirect_to root_path
end
end
end
Aside from your controller action though, it will probably be safer to implement a model-level validation/check to reject it if the date is past, just to be safe (or if you have other ways to update that object in the future). You can do this through the model hook before_save, in which you can pretty much do a similar check that I have given above.
Also, the other caveat is that comparing Time.now could be in a different timezone depending on where your server is. Just be cognisant of this when you do your checks, and cast the time properly with this in mind.

Since you didn't provide a specific implementation, I'm not quite sure if you're having trouble specifically with Ruby or Rails. However, given your question, I would store a datetime variable in your database when the user creates the bet. Every time the user tries to 'update' the bet, check in the database whether or not it's been past that specific time away from the bet creation. Hope this helps.

Related

Dynamic Routes Rails 4, taken from db

Frustrating, I can't find an eligible solution for my problem.
In my Rails 4 app, I want to give my users the possibility to add their own custom post types to their sites. Like:
www.example.com/houses/address-1
www.example2.com/sports/baseball
Both would work, but only for the linked sites. Sports and houses would be the (RESTful) post types, taken from the db, added by users.
I have been struggling to find a elegant solution to accomplish this. I found http://codeconnoisseur.org/ramblings/creating-dynamic-routes-at-runtime-in-rails-4 but that feels kinda hacky and I'm not sure if reloading the routes works in production, I'm getting signals that it won't.
I'd say I have to use routes constraints http://guides.rubyonrails.org/routing.html#advanced-constraints but I don't have a clue how to approach this.
To be clear, I have no problem with the site setting stuff, the multi tenancy part of my app is fully functional (set in Middleware, so the current site is callable in the routes.rb file). My issue is with the (relative) routes, and how they could be dynamically set with db records.
Any pointers much appreciated.
I think route constraints don't work for you because your domain is a variable here. Instead, you should be examining the request object.
In your ApplicationController, you could define a method that would be called before any action, like so:
class ApplicationController < ActionController::Base
before_action :identify_site
def identify_site
#site = Site.where(:domain => request.host).first
end
end
As you scale, you could use Redis for your domains so you're not making an expensive SQL call on each request.
Then you can just add the #site as a parameter to whatever call you're making. I'm assuming you're doing some sort of "Post" thing, so I'll write some boilerplate code:
class PostController < ApplicationController
def show
#post = Post.where(:site => #site, :type => params[:type], :id => params[:id])
end
end
Just write your routes like any other regular resource.

How to use the new ActiveSupport::Testing::TimeHelpers inside controller

Edit to make it more clear
Like the title tells how to use the awesome ActiveSupport::Testing::TimeHelpers#travel_to method inside my controller. Like in tests, I want to achieve something like this:
SomethingConroller < ApplicationController
def index
travel_to some_date do
# some stuff that it depends on the current_date
end
end
end
Tried include the module:
include ActiveSupport::Testing::TimeHelpers
but I got:
uninitialized constant ActiveSupport::Testing
Hoping that the date traveled to will be applied to the view, view_helpers, controller_action
If you must, then add require 'active_support/testing/time_helpers' at the top of the file.
Although I've no idea what you're doing with that code. Try this instead:
SomethingConroller < ApplicationController
def index
#instance = SomeModel.find_by_date(12.days.ago)
end
end
I think you're messing up your concepts here. You should use time travel to put tests in a certain time so that you can test a scenario at that new time. For example, lets say users have to renew their subscription after one year.
create the user(now).
travel to the time a year from now
Make sure that when the user logs in at travelled to time they are duly notified.
To manipulate date for queries, use 12.days.ago, 12.days.from_now, this can be used with seconds,days, minutes, years

Create a logic captcha from scratch

I haven't touched a scrap of code yet, but here's my thoughts on how to do this:
Create a :interactions entry in my session hash. This will contain an array of time stamps. Every time a user goes through any action, the time they did this will be appended to the :interactions entry. The array will be initialized in my sessions controller, and timestamps appended to it via a filter in my application controller:
class SessionsController < ApplicationController
def create
create_session
session[:interactions] = []
end
end
class ApplicationController < ActionController::Base
after_action :log_time
private
def log_time
session[:interactions] << Time.now.to_i
end
end
Then, create another action in my application controller, the one tasked with launching the recaptcha if the user's behaviour is suspicious. All it does is see when we have 20 entries in our session[:interactions] array, find out the time elapsed between each pair of consecutive entries, and then find the average time elapsed between these interactions. If the average time is under two minutes, the recaptcha is launched. The session[interactions] array is then reset.
class ApplicationController < ActionController::Base
after_action :log_time
before_action :launch_captcha
private
def launch_captcha
if session[:interactions].length == 20
elapsed = []
session[:interactions].each_slice(2) do |a, b|
elapsed << b - a
end
total = elapsed.inject(:+)
average = total / 20
if total < 120
# this a part I'm really not sure how to do:
# various instance variables should be populated here
redirect_to 'application/launch_captcha.html.erb'
end
session[:interactions] = []
end
end
def log_time
session[:interactions] << Time.now
end
end
Now, the fact the session[:interactions] is reset may be a bit of a weakness; all bets are off for those twenty interactions. But I want to build on the above logic, maybe add session[:captchas_sent], to the session hash (or even have captchas_sent as a column and save it to the user's record), and if the session[:captchas_sent] is x amount or y amount, warnings or temporary bans could come into effect.
What are your thoughts on the above way of monitoring user behaviour?
Here's where my knowledge of rails is starting to break down though. Once I've redirected the user to the recaptcha page, how should I proceed? I have two tables, questions and answers with a has_many belongs_to relationship between them respectively.
So a random question will come from my questions table, and then I'll have a form that pertains to an answer. It will be an ajax form, and have just one field, a text field for the answer. The action the form links to, human test, will see if the answer given is equal to one of the question's answers. But how should the question's id be passed into this action? It couldn't be a simple hidden field, because once the spammer knows the answer to one question, his script could always set the id to that one question. So the params hash or the sessions hash maybe? I need some advice here guys.
I also don't really know how the human test method should proceed once the it finds the user's answer is equal to one of the question's answers:
Let's say the user is submitting a comment. They fill in the comment, hit the submit button, the launch_captcha action kicks in, and redirects them to 'application/launch_captcha.html.erb'. What has happened to the data in the comment create form? Once they've answered the captcha correctly, how should the human_test method proceed? How could it go on to submit their comment as usual? I just don't know how to do that...I need to create an action that is called before the create action of a form...and..argh I just don't know. Help guys!

Setting current_user in pg_audit_log

I'd like to use pg_audit_log for logging in a rails app. The audit log must not only show the columns that have changed, but also the user who made those changes. The docs don't show how to do this, but after looking through the pg_audit_log source (postgresql_adapter.rb) I see it reads user information from a thread local variable, ala:
current_user = Thread.current[:current_user]
I've considered setting/unsetting this in before and after filters like so:
Thread.current[:current_user] = current_user
(using the current_user helper method in the controller to get the currently logged in user), but that seems dangerous. I'm now spending time trying to understand how the rails request cycle and threads interact, to get a better feel for just how dangerous. In the mean time, I was curious if any SO users currently using pg_audit_log have solved the need to log the user_id and user_unique_name to the log tables each time the user makes a change to a record.
Setting the current user the way you describe is a common way to do it. See, for example, http://rails-bestpractices.com/posts/47-fetch-current-user-in-models
Some example code could look like:
# in your model
class User < ActiveRecord::Base
def self.current
Thread.current[:current_user]
end
def self.current=(user)
Thread.current[:current_user] = user if user.nil? || user.is_a?(User)
end
end
# in your controller
class ApplicationController < ActionController::Base
before_filter :set_current_user
def set_current_user
User.current = user_signed_in? ? current_user : nil
end
end
Relying on the Thread.current hash to provide model-level access to objects managed by the controller is indeed controversial. For example, see the following:
Safety of Thread.current[] usage in rails
It is worrisome that this particular feature is undocumented in the pg_audit_log gem.
Suppose you had not actively explored the gem's source code, and suppose you had independently decided to define Thread.current[:current_user] = something in your own application, for your own purpose. In that case, pg_audit_log would audit that object, without your knowledge.
Granted, the name current_user is so universally accepted to mean the currently logged-on user as defined by authentication routines that it's difficult to imagine this potential bug as a concrete problem, but from a design standpoint? Ouch.
On the other hand, since you know what you are doing, ensuring that Thread.current[:current_user] is set/unset at the beginning/end of each and every response cycle should make the process safe. At least that's what I gather from reading lots of posts on the topic.
Cheers, Giuseppe

Rails3 - Permission Model Before_Save Check?

I have a permission model in my app, that ties (Users, Roles, Projects) together.
What I'm looking to learn how to do is prevent a user for removing himself for their project...
Can you give me feedback on the following?
class Permission < ActiveRecord::Base
.
.
.
#admin_lock makes sure the user who created the project, is always the admin
before_save :admin_lock
def before_save
#Get the Project Object
project = Find(self.project_id)
if project.creator_id == current_user.id
# SOME HOW ABORT OR SEND BACK Not Allowed?
else
#continue, do nothing
end
end
end
Is that look like the right approach?
Also, I'm not sure how to do the following two things above:
How to abort prevent the save, and send back an error msg?
Get the devise, current_user.id in the model, that doesn't seem possible, so how do Rails gurus do stuff like the above?
Thanks for reading through
How to abort prevent the save, and send back an error msg?
return false during the callback chain tells activemodel to stop (similar to how adding errors to the model during a validation tells it to stop at that point)
self.errors.add_to_base "msg" will add an error to the model, which can then be rendered on the view.
Get the devise, current_user.id in the model, that doesn't seem possible, so how do Rails gurus do stuff like the above?
Models shouldn't really know about things like the current request, if at all possible, you should be locking things down at the controller/action level.
EDIT:
So, the role of controllers is to deal with everything involved in getting the correct information together based on the request, and passing it to the view (which becomes the response). People often say "make your models fat and your controllers skinny", but that could be said of any system that embraces object oriented design -- your logic should be in objects when possible.
That being said, the whole point of controllers is to deal with routing the right things to the right places, and authentication is definitely a concern of routing.
You could easily move the line comparing creator_id to user id in the action, and react based on that.
Now, sometimes you genuinely need that stuff in the model and there is no way around it. That becomes a problem, because you need to fight rails to get it there. One way would be to attr_accessor a current_user field on your model, and pass that in on initialize. Another would be to remove the fields from the params hash that a user is not allowed to change in the action. Neither is really that nice though.
Agreed with Matt that you should try to use the controller for the redirect. The model should have the logic to determine if the redirect is appropriate. Maybe something like
class ProjectsController < ApplicationController
def update
redirect_to(projects_url, :alert => "You can't remove yourself from this project.") and return if Role.unauthorized_action?(:update, params[:project])
#project = Project.find(params[:id])
if #project.update_attributes(params[:project])
...
end
class Role
def self.unauthorized_action?(action, params)
# your logic here
end
You should check out CanCan for some ideas.
In permission model take one field project_creater as boolean
In project modelbefore_create :set_project_ownership
def set_project_ownership
self.permissions.build(user_id: User.current.id, project_creater: true)
end
In project controllerbefore_filter :set_current_user
In Application controllerdef set_current_user
User.current = current_user
end

Resources