Handling ambiguous routes in Rails - ruby-on-rails

Here's my dilemma: I have two types of routes which are semantically very different, and should go to different controllers.
ny/new-york/brooklyn/cleaners # should go to a list of cleaners for a neighborhood
ny/new-york/cleaners/mrclean # should go to an individual cleaner's page
Note that "brooklyn" and "cleaners" here are just examples. The app has many service types (e.g. "cleaner") and many neighborhoods, so it's impossible to hard-code a list of either into a regular expression and use that to distinguish the two routes.
Is it possible to involve an arbitrary method, which accesses ActiveRecord models, in the routing decision? I'm using Rails 2.3.8.

Edit : new answer with dynamic services
Looking at this blog entry it seems possible to use ActiveRecords in the routes.
Maybe you could do something like this :
service_names = Service.all.map(&:short_name) # assuming the property 'short_name' is the value used in urls
service_names.each do |service_name|
map.connect ':state/:city/#{service_name}/:company' :controller => ‘company’, :action => ‘show’ # to show the company's page
map.connect ':state/:city/:neighborhood/#{service_name}_finder' :controller => ‘company_finder’, :action => ‘find’ # to list the companies for the given service in a neighborhood
end
That should still prevent conflicts since the routes for a certain service is before a route for a neighborhood
Old bad answer
Can't you use the two following routes ?
map.connect ':state/:city/cleaners/:cleaner' :controller => ‘cleaners’, :action => ‘show’ # to show the cleaner's page
map.connect ':state/:city/:neighborhood/cleaners' :controller => ‘cleaner_finder’, :action => ‘find’ # to list the cleaners of a neighborhood
In your controller, you should be able to retrieve :state, :city and others value using params[:state], params[:city], etc.
Putting the :state/:city/cleaners/:cleaner on the first line should prevent ambiguity.

Related

Rails: Difference between List and Index

I appreciate this is an incredibly noob question, but having Googled multiple combinations of search terms I regretfully am still in the dark. These things can be difficult when one doesn't know and so obvious when one does.
I have semi-home page where incoming customers can choose to see a queried list or do a handful of other things. This isn't a home page but a sort of mini 'switchboard' within the site.
The seven standard RESTful Rails controller methods are (as I understand them):
List # shows a list of records generated with .find(:all)
Show # shows details on one record
New # initiates new record
Create # saves and renders/redirects
Edit # finds and opens existing record for edit
Update # updates attributes
Delete # deletes record
What to use when some users need to see a selected 'list' of records that isn't literally .find(:all)? How would this work given I still need a list function that gives me .find(:all) for other purposes?
I've heard of 'index' being used in Rails controllers, but I don't know the difference between index and list.
For best practice and best design, what controller methods would you use for a mini-switchboard (and other intermediate pages such as 'About Us')?
Any specific answers would be a bit more useful than links to http://guides.rubyonrails.org/action_controller_overview.html etc. :) Thanks very much.
First, I think it's important to note that the "standard methods" are neither standard nor methods in a sense. These are considered actions, and are only standard in that they are the conventions used with scaffolding. You can create any number of actions and group them logically with a controller.
If you open up [Project]/config/routes.rb and read through the comments, I think you'll understand a little better how controllers and actions map to a specific route. For instance, you can create a named route to the login controller's login action and call it authenticate by adding to the top of your routes.rb:
# ex: http://localhost/authenticate
map.authenticate 'authenticate', :controller => 'login', :action => 'login'
# map.[route] '[pattern]', :controller => '[controller]', :action => '[action]'
# ex: http://localhost/category/1
map.category 'category/:id', :controller => 'categories', :action => 'list'
# ex: http://localhost/product_group/electronics
map.search 'product_group/:search', :controller => 'products', :action => 'list'
To partially answer your question, you may want to consider adding a category model and associating all products to a category. then, you can add a named route to view items by category as in the code block above.
The major benefit to using named routes is that you can call them in your views as category_url or category_path. Most people don't want to do this and rely on the default route mappings (at the end of the routes.rb):
# ex: http://localhost/category/view/1
map.connect ':controller/:action/:id'
# ex: http://localhost/category/view/1.xml
# ex: http://localhost/category/view/1.json
map.connect ':controller/:action/:id.:format'
The key thing to mention here is that when a URI matches a route, the parameter that matches against a symbol (:id, or :search) is passed into the params hash. For instance, the search named route above would match a search term into params[:search], so if your products have a string column called 'type' that you plan to search against, your products controller might look like:
class Products < ApplicationController
def list
search_term = params[:search]
#products = Product.find(:all, :conditions => ["type = ?", search_term])
end
end
Then, the view [Project]/app/views/products/list.html.erb will have direct access to #products
If you'd really like an in-depth view into Ruby on Rails (one that is probably 10 times easier to follow than the guide in the link that you posted) you should check out
Agile Web Development with Rails: Second Edition, 2nd Edition

Using named routes vs. using url_for()

When should one use named routes vs. using url_for with a {:controller => "somecontroller", :action => "someaction"} hash?
Is one preferred over the other and why? Is one more maintainable or more efficient w.r.t. performance?
It might help to understand what named routes are doing.
Defining a Named route creates a wrapper around url_for providing the options required for the created route. Routing resources creates many named routes.
With that in mind, the overhead of calling a named route as opposed to url_for with the options needed is negligible. So if you're linking to a specific resource, named routes are the way to go. They're easier to read, type and maintain.
However, don't discount url_for. It has many creative uses thanks to the way it handles missing options. It is very useful when it comes to keeping views DRY that are used from multiple nested sources. Ie: when you have a blog_posts controller and posts_controller sharing the same views.
I strongly encourage you to read the url_for documentation. To help figure out where those places it makes sense to use url_for are.
I would prefer named routes as it's shorter and does the same thing.
named route is very neat.
map.with_options :controller => "company", :action => "show", :panel => "name" do |m|
m.company '/company/:action/:id/:panel'
end
Then you can call
company_url :id => 1
If you set up your routes and resources carefully, you shouldn't need any hash routes, only named ones (either built-in via map.resource or custom map.<something> ). Hash routes are useful, if you have to create links based on dynamic content. Something like:
link_to #post.title, :controller => (#user.is_admin ? 'admin/posts' : 'public/posts'), :action => 'show', :id => #post
(This is just a forced example, but you should get the gist of it :)

Rails routing with requirements

with the following routes I try to achive the goal, that I can present static resources like terms of use, imprint and so on in different languages using different urls.
I defined two example routes for my imprint like that:
map.imprint ':lang/impressum', :controller => "statics", :action => "imprint", :requirements => {:lang => /de/}
map.imprint ':lang/imprint', :controller => "statics", :action => "imprint", :requirements => {:lang => /en/}
Now in my view I try to use the path/url helper like that:
<%= link_to(t(statics.imprint.linkname), imprint_url(:lang => session[language])) %>
where there session[:language] is "de" or "en".
Thats results in a working link for the de route. But the english one fails. If I change the order of the routes, it's vice versa, and the english one works, while the german one fails.
The error always reads like that:
imprint_url failed to generate from {:controller=>"statics", :lang=>"de", :action=>"imprint"}, expected: {:controller=>"statics", :action=>"imprint"}, diff: {:lang=>"de"}
Can anyone help out with this?
Thanks.
Jason
As far as I know, you cannot map two routes to the same name like that.
You would need to rename one of them, ie
map.impressum
map.imprint
When Rails looks up the route, it will stop at the first one that it finds, that's why your 'de' links are working.

Validate no routing overlap when creating new resources in Ruby on Rails

I've got a RESTful setup for the routes in a Rails app using text permalinks as the ID for resources.
In addition, there are a few special named routes as well which overlap with the named resource e.g.:
# bunch of special URLs for one off views to be exposed, not RESTful
map.connect '/products/specials', :controller => 'products', :action => 'specials'
map.connect '/products/new-in-stock', :controller => 'products', :action => 'new_in_stock'
# the real resource where the products are exposed at
map.resources :products
The Product model is using permalink_fu to generate permalinks based on the name, and ProductsController does a lookup on the permalink field when accessing. That all works fine.
However when creating new Product records in the database, I want to validate that the generated permalink does not overlap with a special URL.
If a user tries to create a product named specials or new-in-stock or even a normal Rails RESTful resource method like new or edit, I want the controller to lookup the routing configuration, set errors on the model object, fail validation for the new record, and not save it.
I could hard code a list of known illegal permalink names, but it seems messy to do it that way. I'd prefer to hook into the routing to do it automatically.
(controller and model names changed to protect the innocent and make it easier to answer, the actual setup is more complicated than this example)
Well, this works, but I'm not sure how pretty it is. Main issue is mixing controller/routing logic into the model. Basically, you can add a custom validation on the model to check it. This is using undocumented routing methods, so I'm not sure how stable it'll be going forward. Anyone got better ideas?
class Product < ActiveRecord::Base
#... other logic and stuff here...
validate :generated_permalink_is_not_reserved
def generated_permalink_is_not_reserved
create_unique_permalink # permalink_fu method to set up permalink
#TODO feels really ugly having controller/routing logic in the model. Maybe extract this out and inject it somehow so the model doesn't depend on routing
unless ActionController::Routing::Routes.recognize_path("/products/#{permalink}", :method => :get) == {:controller => 'products', :id => permalink, :action => 'show'}
errors.add(:name, "is reserved")
end
end
end
You can use a route that would not otherwise exist. This way it won't make any difference if someone chooses a reserved word for a title or not.
map.product_view '/product_view/:permalink', :controller => 'products', :action => 'view'
And in your views:
product_view_path(:permalink => #product.permalink)
It's a better practice to manage URIs explicitly yourself for reasons like this, and to avoid accidentally exposing routes you don't want to.

Param name and value (independantly) as part of Rails Route

DocumentsController#common_query can handle multiple different request styles.
i.e. all docs in batch 4 or all docs tagged "happy"
I want a single route to make em pretty, so:
/documents/common_query?batch=4
/documents/common_query?tag=happy
become:
/documents/batch/4
/documents/tag/happy
So the end result is that #common_query is called but part of the url was used as the param name and part as it's value.
The second option, with two routes, is almost certainly the better way to go, because it will only match the kinds of URLs that you want to support, while the first option will also "match" URLs like /documents/foo/bar, which will likely cause your #common_query method to, at best, return a RecordNotFound (404) response. At worst, if you're not ready to not see any of your expected params, you'll get a 500 error instead...
Of course, if you start having a lot of variations, you end up with a lot of routes. And if you need to use them in combination, e.g., /documents/batch/4/tag/happy, then you'll need to use a wildcard route, and do the parameter processing in your controller. This might look something like:
map.connect 'documents/*specs', :controller => "documents_controller", :action => "common_query"
The various elements of the URL will be available your controller as params[:specs]. You might turn that into a find like so:
#items = Item.find(:all, :conditions => Hash[params[:specs]])
That Hash[] technique converts the one dimensional array of options into a key-value hash, which might be useful even if you're not feeding it directly to a find().
As a single route:
ActionController::Routing::Routes.draw do |map|
map.connect "documents/:type/:id", :controller => "documents_controller",
:action => "common_query"
end
Then params[:type] will either be "batch" or "tag", and params[:id] either "4" or "happy". You will have to make sure that other actions for the DocumentsController come before this in the routes because this will match any url that looks like "documents/*/*".
But why does it have to be a single route? You could use two routes like this:
map.with_options(:controller => "documents_controller",
:action => "common_query") do |c|
c.connect "documents/batch/:page", :type => "batch"
c.connect "documents/tag/:tag", :type => "tag"
end
which will have the same effect, but is more specific, so you wouldn't have to worry about the priority order of the routes.

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