I hoped route constraints would allow me to have admin.example.com/widgets/ and example.com/admin/widgets/ be effectively the same, with the URL helper admin_widgets_path pointing to the correct one based on the current subdomain. However, the route helper seems to only point to one or the other regardless of constraints.
Am I doing something wrong? Is this a bug? Is there a better way to solve this problem?
A rails app with an example of the problem has been published here, but the relevant details are below.
My config/routes.rb
class Subdomains
# any domain that starts with 'admin.'
def self.admin?
-> (request) { request.host =~ /^admin\./ }
end
# any other domain
def self.primary?
-> (request) { !admin?.(request) }
end
end
Rails.application.routes.draw do
constraints(Subdomains.primary?) do
namespace :admin do
resources :widgets
end
end
constraints(Subdomains.admin?) do
scope module: "admin", as: :admin do
resources :widgets
end
end
root to: "admin/widgets#index"
end
My app/views/admin/widgets/index.html.erb
<%= link_to "Widgets", admin_widgets_url %>
In this configuration, admin_widgets_url always returns /admin/widgets/ which isn't a valid route on admin.example.com so clicking the link results in a routing error on that subdomain. If the admin subdomain constraint block is put first in the routes, then the URL helper always returns /widgets/, breaking the link on a non-admin domain.
The routes otherwise work, but not sure how to get the URL helpers to point to the correct one.
Your expectations are wrong - Rails reads the entire routes definition as part of the setup phase. This is also when the route helpers are created. The constraint is not actually evaluated until later when the request is matched.
Rails splits this into distinct phases to allow forking.
Instead you may need to override the route helpers.
Related
Currently if you wish to add a constraint there are many ways to do it but as I see currently you can only include one definitive method which is called. E.g.
Class Subdomain
# Possible other `def`s here, but it's self.matches? that gets called.
def self.matches?( request )
# Typical subdomain check here
request.subdomain.present? && request.subdomain != "www"
end
end
The problem with the above approach is it doesn't handle routes prefixed in www, that is admin and www.admin are indistuingishable. More logic can be added, but if this was required over a set of static subdomains like admin, support, and api you currently need to make SubdomainAdmin, SubdomainSupport etc....
This can be solved with regex as follows in routes.rb:
admin
:constraints => { :subdomain => /(www.)?admin/ }
api
:constraints => { :subdomain => /(www.)?api/ }
If requests were even more complex than this things get tricky. So is there a way to add individual methods inside a class used for constraints?
Essentially, how is the below achieved? Is it even possible? Whats the best method of white-listing subdomains to use?
E.g.
Class Subdomain
def self.admin_constraint( request )
# Some logic specifically for admin, possible calls to a shared method above.
# We could check splits `request.subdomain.split(".")[ 1 ].blank?` to see if things are prefixed with "www" etc....
end
def self.api_constraint( request )
# Some logic specifically for api, possibly calls to a shared method above.
# We could check splits `request.subdomain.split(".")[ 1 ].blank?` to see if things are prefixed with "www" etc....
end
def self.matches?( request )
# Catch for normal requests.
end
end
With which we can now call constraints specifically as follows:
:constraints => Subdomain.admin_constraints
And all generic constraints as follows:
:constraints => Subdomain
Is this possible in Rails 4.0.3?
The router will call the #matches?(request) method on whatever object you pass the route. In the case of
:constraints => Subdomain
you're giving the route the Subdomain Class object. However, you could also pass an instance, which you could configure via arguments. e.g.,
Class Subdomain
def initialize(pattern)
#pattern = pattern
end
def matches?(request)
request.subdomain.present? && #pattern ~= request.subdomain
end
end
# routes.rb
namespace :admin, constraints: Subdomain.new(/(www.)?admin/) do
# your admin routes here.
end
NOTE: I didn't verify that code works, I just wrote it off the top of my head, so consider it more of pseudo-code than implementation ready.
Also, you can see an example of this technique, with some more details, at: Use custom Routing Constraints to limit access to Rails Routes via Warden.
I have the following wildcard routes & constraints setup ...
get '*path' => 'profiles#show', constraints: SlugConstraint.new
get '*path' => 'blogs#show', constraints: SlugConstraint.new
and
class SlugConstraint
def initialize
#slugs = Slug.all.map(&:name)
end
def matches?(request)
request.url =~ /\/(.+)/
#slugs.include?($1)
end
end
... a variation based on the issue I described here:
Rails wildcard route with database lookup & multiple controllers
My issue now is that if the first call to SlugConstraint.new returns false (so that the 2nd routes.rb SlugConstraint.new now gets called) I don't want to have to redo the call to:
Slug.all.map(&:name)
How do I properly save (or scope) the #slugs data from the first constraint call that failed, so that I can access it if needed in the next constraint call?
Thanks.
Routing
You're not going to be able to use 2 routing patterns for the same path
When you send a request to Rails (or any other MVC application), Rails will take the path you've sent & consequently try to assign the right route (controller#action) for it.
This happens sequentially - IE Rails will look through your routes from top -> bottom until it finds one which corresponds. As you have two routes to match the same path, you're not going to be able to use the set up you have
--
App-Wide Slugs
What you're looking for is something called app-wide slugs - which essentially means you're able to manage a single slug path, and have a system in the back-end to accommodate it.
You're on the brink of being able to achieve this, and whilst I don't have any code to help, I do have an idea, which I found here:
#config/routes.rb
get '*path' => MyRouter.new, constraints: SlugConstraint.new
#lib/my_router.rb
class MyRouter
def call(env)
# Matched from routes, you can access all matched parameters
view_name= env['action_dispatch.request.path_parameters'][:view_name]
# Compute these the way you like, possibly using view_name
controller= 'post'
my_action= 'show'
controller_class= (controller + '_controller').camelize.constantize
controller_class.action(my_action.to_sym).call(env)
end
end
This will allow you to pick up the slugged paths, whilst routing to the correct controller. This is TOTALLY untested & just a stab in the dark - if you want to go over it with me, comment & we can have a look
I have a custom route based on http://guides.rubyonrails.org/routing.html#advanced-constraints that checks for redirects based on a url entered.
For instance /site may redirect to /mysite
Here is the code:
class RedirectCheck
def initialize
#redirects = Redirect.all_from_paths
end
def matches?(request)
#redirects.include?(request[:path])
end
end
MyApp::Application.routes.draw do
get ":path" => 'redirects#show', constraints: RedirectCheck.new
end
Redirect.all_from_paths basically is a model method that returns an array of all the accepted routes and then 'redirects#show' does the actual redirect.
Now my problem is that the route..
get ":path" => 'redirects#show', constraints: RedirectCheck.new
..will not accept paths with slashes in them
So for example I can't add a path like /go/some/where my redirect route will not recognize it
How do I change this line so it will accept any path with any number of slashes and passes it as params[:path] to 'redirects#show'?
What you want is:
get "*path", to: 'redirects#show', constraints: RedirectCheck.new
And there are many other examples at the Rails routing guide.
I have to modify the routes file in order to have SEO improvement.
This is my context, a rails backend generate a JSON feed with the route's name in, I have to read it and change the default name.
For example, I have this:
get '/people' => 'people#show', as: :people
and I'd like to change /people in some value read from my JSON feed.
I created a class to get the JSON object in my app
class JSONDatabase
def initialize(kind_of_site)
#kind_of_site = kind_of_site
end
def fetch_database_remote(url)
JSON.parse(open(url).read)
end
end
but how can i access it in routes file?
Thank you
You don't necessarily need to modify your application's routes. What you can do is define a wild card route that leads to a unique controller where you read the updated route. This approach is kind of hackish but gives you the unlimited routes you need without modifying the routes.
Your config/routes.rb file would look something like this:
resources :defined_models
root to: 'controller#action'
# At last we define the wildcard route
get '/:route' => 'routing_controller#routing_action'
Then, at this routing action we can do the job of seeing if this route (now defined in the params[:route] variable) corresponds to the modified one. Just remember to redirect to a 404 if the route given is not defined, since with this approach you loose the Rails default way of dealing with undefined routes.
I have a community_users model that I route in the following way:
resources :communities do
resources :users
end
This creates the route /communities/:id/users/.
I'd like to configure this route so that only the name of the community with the corresponding :id is shown.
In other words, if a community has an id of '1' and the name 'rails-lovers' - the route would read:
/rails-lovers
and not:
/communities/1/users/
You might want to check out the gem friendly_id
That will give you the clean URLs you are looking for.
I'm not quite sure if this is what you're looking for, but:
One option would be to create the route
match ':community_name' => 'users#show_users_for_community'
and then in the UsersController have
def show_users_for_community
#community = Community.find_by_name(params[:community_name])
<do what you need to do here>
end
I'm not sure if that route will match too many URLs or not -- it's a very general route. So if you do this, maybe put it low down in your routes file.