Rails Tutorial- cannot get rails to recognize route - ruby-on-rails

I am new to programming in general, someone referred me to railstutorial.org.
Specs: I am working on a cloud9 IDE, as suggested in the tutorial.
Information: I am on 1.3 of the rails tutorial, which is setting the root route.
The problem was initially my route did not effect the server launch (root page was still ruby default, not to 'application#hello'). Here are the files that the tutorial said to edit.
routes.rb
Rails.application.routes.draw do
root to: 'application#hello'
end
application_controller.rb
class ApplicationController < ActionController::Base
protect_from_forgery with: :exception
def hello
render text: "Hello, world!"
end
end
There are a lot of comments that were defaulted into the files that I left out.
I have followed the instructions precisely. After I first had trouble, I thought I may have made an installation error, so I deleted my IDE and restarted, paying extreme attention to detail, especially versions.
I have tried $ rake routes, and my understanding it gives the message:
You don't have any routes defined!
That leads me to believe that the problem is the routes.rb file. I have tried changing the syntax to:
root to: 'application#hello'
I don't know a whole lot, such as how it would work using application, so I also tried:
root 'ApplicationController#hello'
and
root to: 'ApplicationController#hello'
These all result in the no routes defined message. I have no idea what is going on.
Thanks for any input or help!

You could try root 'application#hello' in your routes. Also, when starting out simple things like forgetting to save the file before trying things out on the browser can slip by; restarting the server takes care of a surprising number of foibles.
The rails documentation can also provide you a bit more information beyond the tutorial.

You probably want to move that action outside of the ApplicationController to another controller, but if you really insist, you can put this into your routes.rb:
get '/hello', to: 'application#hello', as: :hello
If you want the page to be the root, I would recommend creating a StaticPagesController and defining hello there, instead of putting it inside ApplicationController.
Here's what you can do:
Run rails g controller static_pages
Inside your StaticPagesController.rb, copy and paste your hello method that was inside ApplicationController.
Change the routes.rb to root 'static_pages#hello.
and you should have your desired result.

I've followed the same tutorial and I can say that the materials covered in the first two chapters are quite complicated at first if you are new to programming. It's only after you've done the entire tutorial that it will become clear to you how this routing thing (or any other details in these chapters for that matter) actually works.
However, since this idea of routing is very important, it's not a bad idea to understand how it works even if you are at an early stage in the tutorial.
The way you can create a route in rails is that you first specify a proper HTTP verb (GET, POST, PATCH, DELETE) with an appropriate path, the name of a controller, followed by a hash sign (#) and the name of an action defined in the controller.
Here controller is just a ruby class and an action a ruby method. (Since the basic principle of ruby on rails is "convention over configuration", it's important to get used to the terminology like controller, action, routing etc...)
When you say
get '/hello' => "application#hello"
(yes, you can use => in place of to:) as takeriho suggests, what happens is that a GET request to a URL of the type /hello(/ being "root path" as in www.example.com/(note the / at the end)) will get routed to the action, or method, named hello defined in a controller, or a class, named ApplicationController.
If you take a look at application_controller.rb, you can see that a method hello is defined within a class ApplicationController.
class ApplicationController < ActionController::Base
.....
def hello
render text: "Hello, world!"
end
end
Now if you want to specify a root route, which is your original question, you can just do root followed by the name of a controller, a hash sign (#), and the name of a class. So the code
root "application#hello"
means that a request to a url of the form /, or a root_path as it's called in rails convention, will get routed to the action (or method) named hello defined in a controller (or a class) named ApplicationController. You could accomplish the same result by doing
get '/' => "application#hello", as: :root
(you can name a route by adding as: :custom_name) but rails is smart enough to know that the two are equivalent. The task is made easier by following the rails conventions.
If you are completely new to Rails, I highly suggest you check out the Rails courses in Pragmatic Studio before going through the Ruby on Rails Tutorial which, as the author suggests, is not for a complete beginner. This approach worked perfectly for me. The rails courses offered by Pragmatic Studio assumes you have no prior knowledge about programming, and explains the basics in a manner much clearer than I did in this answer.
Happy coding :)

Related

Ruby on Rails match routing error

I'm trying to make a Rails application that serves simple static HTML pages. I followed Mikel's tutorial here (it involves making a Pages controller and setting up some routing) but I keep getting an error message.
I made a app/views/site/pages/_about.html.erb file to contain my About page. After starting the rails server, I try to go to http://localhost:3000/about/ but it gives me a Routing Error because I have an "uninitialized constant Site."
My project is uploaded to GitHub if you want to take a look at the code.
Edit: here's my config/routes.rb file:
NINAgallery::Application.routes.draw do
match ':page_name' => 'site/pages#show'
end
And here's the important part of my app/controllers/pages_controller.rb file:
class PagesController < ApplicationController
layout 'site'
def show
#page_name = params[:page_name].to_s.gsub(/\W/,'')
unless partial_exists?(#page_name)
render 'missing', :status => 404
end
end
# extra code for handling 404 errors goes here
end
site/pages#show means the show action in Site::PagesController
You either need to put your controller in the namespace your routes imply or change the route
The last line in the PagesController is this:
ValidPartials = Site::PagesController.find_partials
That means that the PagesController is contained in a Site module. But there is no Site module in your app.
I think simple removing Site:: should fix the problem:
ValidPartials = PagesController.find_partials
Plus the route:
match ':page_name' => 'pages#show'
Your application is called NINAgallery.
Replace Site in pages_controller.rb line 27 by NINAgallery.
PS:
I just took a peek at the so-called tutorial. You are taking really really really bad habits.
Some resources to take very good basics:
http://guides.rubyonrails.org/
http://api.rubyonrails.org/
If you like tutorials: http://ruby.railstutorial.org/
And there are plenty of books about rails. All good.
Besides the namespace problem, you also needed to add the 'app' Gem to the Gemfile, as explained in the tutorial.
I don't know why you removed the caching of the static pages in your working code. I made a pull request with the app working and maintaining the cache problem. If another person is interested, the code is here
Also ryan bates has a tutorial called "Semi static pages" that does something similar. I would encourage you to follow his solutions because there are very rarely mistaken.

Using Ruby on Rails link_to to link to controller action

I'd just started toying around with Ruby on Rails and had come across an issue with linking to another action in a controller from a particular view. I am almost certain it's an issue (or lack of code) in my routes.rb file, but I think I'm misunderstanding exactly how this file works & what I have to do. I've got a solution but pretty sure it's not the "best way" to do it.
I have one controller called home with two actions, index (which is the default) and newbill. Inside index.html.erb I have:
<h1>Home View</h1>
<%= link_to "new", :controller => "home", :action => "newbill" %>
However I was getting a routing error:
No route matches {:controller=>"home", :action=>"newbill"}
Doing rake routes gives me the following:
root / {:controller=>"home", :action=>"index"}
I then (following some Googling) added this code to routes.rb
match 'home/newbill' => 'home#newbill', :as => :newbill
And then in my index.html.erb I've got this:
<%= link_to "Name", newbill_path %>
And now this works as expected. My questions however are:
Why does this work? What exactly is going on behind the scenes?
Surely this is not the best way to do it? Adding another match 'home/newbill'... for every controller / action I want to link to seems a rubbish way of doing things.
I really like Ruby, but struggling a bit with this aspect of Rails...routing in general is messing up my head a bit I think!
Any help is much appreciated :D
Thanks,
Jack
I guess the first time your code didn't work because your home controller is defined as a resource.
If you define a controller as a resource in routes.rb file it will support only 7 standard methods (according to REST architecture):
index
new
create
show
edit
update
destroy
If you need any more custom routes you should add them manually, say in your case 'newbill', may go as:
resources :home do
collection do
get :newbill
end
end
But as per my understanding, your newbill method should go to bills controllers new, method not in the home controller.
You are right, Rails routes are little bit confusing (at least for me), but once you understand you can do lots of cool stuff.
Read here for the Rails official routes documentation:
http://guides.rubyonrails.org/routing.html.
You should check out the Rails Routing guide. A read through will help you understand what is going on behind the scenes.
This works becuase rails filters every request through the router looking for a match. This enables you to define custom routes such as domain.com/post when the path is actually blog#post. Prior to rails 3, a catch-all route was the last route in the routes file. This allowed you to define a controller and action and it would just work. I'm on my iPad and not near any projects, so I can't verify it, but I think that route is still there in rails 3.1, it just needs to be umcommented.

error on rails 3

Hi this is ROR beginner's question.
I have creat controller.rb and view hello.rhtml following the tutorial, but when I try to open localhost:3000/say/hello, it come up with with error: No route matches [GET] "/say/hello"
could any one advice please?
Well you need to setup a route for that in your config/routes.rb file.
For first try i would say use a script generator, enter on the command line as being in the project library > rails g controller helloworld index. This will create a route for itself, and a controller file.
After this script runs, there should be a line in your config/routes.rb
Cloud::Application.routes.draw do
get "helloworld/index"
end
Then you need to enter localhost:3000/helloworld/index in your browser url bar. Then ( as default ) rails will render the view located in app/views/helloworld/index.*. If you want to change this behaviour, go to the helloworld controller.
For more info there is a useful guide: ROUTING GUIDES
You need to define a route definition so that the URL you are requesting gets mapped to an action in the controller you have created which would render hello.rhtml. Say your controller name is says_controller.rb (thats how Rails gives the filename). In that if you define and action hello which would by default render hello.rhtml, then the fallback routes which are defined in the routes.rb file at the end would make a request to say/hello to look for the say_controller and hello action, thus rendering hello.rhtml.
For detailed help you can refer to the Rails Guides. There is a lot of helpful material and it is explained very well.
I started developing RoR recently and the best practise I got was the tutorial # rails for zombies and video's # railscasts. I suggest you watch some / make some and you get a general idea how to get started :)
-edit- on this issue: You're trying to render the hello view from the say controller.
since routing is handled by default on :controller/:action, do you have a action called hello in say? No action means no route means no view rendered.
class SayController < ApplicationController
def hello
#do nothing or add some code
logger.debug "I'm in the say controller, hello action!"
end
end
This should get it to render the hello file. You might want to take a look at restful actions / crud though, rails uses those by default.

How do I access all routes, when an App and an included AppEngine gem define controllers with the same name?

I have an engine (developed by me / the company I work for) that we use on several different projects. I just converted it to work with rails 3.1 w/ assets pipeline and everything seems to be working... for the most part.
My problem is that I need to extend the functionality of the UsersController with a little bit of app-specific spice, but I'm not sure about the best way to do it. The engine doesn't define a Users#show action, but this app does need it, so I added to the routes file:
JobEngine::Application.routes.draw do
root :to => 'home#index'
resource :users, :only => [:show]
resources :jobs, :only => [:show]
end
Then in my application I created the UsersController:
class UsersController < MyEngine::UsersController
def show
end
end
Then I made a users/show.html.haml view, I've stripped it down to only show one of the problem lines:
= link_to "Somewhere", job_path(3)
This gives me an error that reads undefined method 'job_path' for #<#<Class:0x00000102d69900>:0x00000102d4ed30>
Which is bizarre because before I made my app's UsersController inherit from MyEngine::UsersController it worked just fine.
When I do rake routes in the console, there are these lines:
users GET /users(.:format) {:action=>"show", :controller=>"users"}
job GET /jobs/:id(.:format) {:action=>"show", :controller=>"jobs"}
I can alter the class definition to be:
class UsersController < ApplicationController
and then the link works just fine. However, the engine's controller MyEngine::UsersController already inherits from ApplicationController. I can put code into my app's ApplicationController (like a before_filter) and it will run as expected, so I know my class definition does ultimately hit my app's ApplicationController, why is the job_path helper not working?
When I change the show action to read:
def show
job_path(3)
end
I get the error:
ActionController::RoutingError (No route matches {:action=>"show", :controller=>"jobs", :id=>3}):
app/controllers/users_controller.rb:9:in `show'
Which further confuses me because now it actually does recognize job_path as a method, but somehow the router isn't picking up where to go with all the correct parameters.
What am I doing wrong? What is the correct way to extend engine controller functionality? I saw the extending engine functionality question here.
And followed that code example, changing my class definition to instead re-open MyEngine::UsersController but I still get the exact same results concerning job_path(NUMBER)
UPDATE:
Ok I sort of figured out what's going on. Let's say your engine has a job_path route, and your application has a job_path route. If you're on a page that was accessed via an engine's controller, you can call the engine's helper with just job_path, but you can also call the main application's helper with main_app.job_path.
Likewise, if you're on a page accessed via one of your application's controllers, you access the engine's helper with my_engine.job_path and your own application's helper with job_path. This is assuming that you have something like mount MyEngine::Engine => "/my_engine", :as => 'my_engine'.
When you inherit an engine controller from your application, it then completely changes your route helpers to think you're in the context of the engine through the controller/view lifecycle. So to fix my problem all I really have to do is change it to be main_app.job_path(3) and it works.
I'm not completely satisfied with this solution because it feels a little...weird. Maybe I have a partial on this page that will be used on a separate non-inheriting page. Now the link helper will only work for one of the two pages, but never both =\ Am I missing something here...?
Try changing your Mount path in main app's routes with below,
mount MyEngine::Engine => "/"
This would solve your problem.
Though you can make this approach work, the semantics do not create a clean architecture. You can surmise this from the duplication of the Users controller - which implies that some User functionality is handled in the AppEngine, and some is handled in the parent app itself.
Instead, think about what functionality exists uniquely within the app, and which is packaged into the AppEngine gem. Perhaps with JobEngine, as you call it, your Users controller there is actually a UsersStatisticsController and, in the app, the controller there is the 'true generic' UsersController that handles CRUD, profiles, message queue, etc.
If you feel you must unify them into a single controller (rather than giving them distinct nomenclature), then you are best to create a Namespaced controller, where the various functionality can be conjoined thereby.
Even though this adds complexity, it's generally arguable that this is the most sound solution. Here's another post on SO about it

Blank page when navigating to http://localhost:3000/say/hello

I'm new to Ruby on Rails and am doing my first tutorial and am running the latest version of rails 3 and ruby 1.9.2. After creating my controller and navigating to http://localhost:3000/say/hello I'm receiving a blank page. I do see the Welcome to Rails message when I just go to http://localhost:3000. I've done some Google searches and people have similar problems but there is no clear fix. I've never really worked with MVC before so the concept of routing is fairly new to me.
Below is my controller:
class SayController < ApplicationController
def hello
end
def goodbye
end
end
My view:
<h1>Say hello to Rails!</h1>
You should delete the public/index.html file as that will mess with your routing and display by default. Have you set up your routes already, and what is the exact location and filename of the template?
You will need something like in your config/routes.rb file to correctly route that url to your template/view:
match '/say/hello' => 'say#hello'
First delete the index.html file from your public folder. Then, go to the app/views and check the views for the say controller. You should have a hello.html.erb.
The answer to your particular question was answered already by Bitterzoet, but I thought you might want some alternative learning resources.
I'm not sure which tutorial you're starting with, but I find it odd that they're not using RESTful routes. You can find out what routes you have set up at the moment by going to the console and typing "rake routes". If you would like a different tutorial, I recommend the one here:
http://www.wiki.devchix.com/index.php?title=Rails_3_Curriculum
I'd also recommend http://railsforzombies.org/ as a good first-time rails experience.
A fun general line to add to config/routes is:
match ':controller(/:action(/:id(.:format)))'
While developing, this will allow you to display the controller/action in address bar for ALL controller/action/id.format etc.
Like Bitterzote wrote, if controller is "say" and action is "hello", http://localhost:3000/say/hello .
If you use controller "say" and action "move", http://localhost:3000/say/move .
I've found this route to be very useful during development, but change this if you launch your application! (Rails warns: "Note: This route will make all actions in every controller accessible via GET requests.")

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