Change From :Id in URL in Rails 3 Routing - ruby-on-rails

Boy this seems like a piece of cake, but I can't find it in the routing bible --
Is there a way to change the default parameter ':id' to something else like ':pid' without using 'match /post/:pid'? I want to avoid using 'match' because it feels particularly brittle.
Edit To confirm, this is only a success if i can do:
pid = params[:pid]
Doing:
pid = params[:id]
works already, but is wrong code, because it's not an id in there.

If I got you right check this out:
http://railscasts.com/episodes/63-model-name-in-url
Basically you should override to_param method in the model:
def to_param
pid
end
And when you will want to fetch an object, do this in the controller:
#object= Object.find_by_pid(params[:id])
Good luck!

You can define a to_param method in your model:
def to_param
pid
end
Then all of your generated links, etc. will use the pid instead of id. And in your controller, params[:id] will actually give you pid, not id.

Related

Rails force to_param to return something even when not persisted

I need to handle a particular case of generating email views with URLs constructed from non-persisted data.
Example : assume my user can create posts, and that triggers a post creation notification email, I'd like to send the user an example of fake post creation. For this, I am using a FactoryGirl.build(:post) and passing this to my PostMailer.notify_of_creation(#post)
In everyday Rails life, we use the route url_helpers by passing as argument the model itself, and the route generator will automatically convert the model into its ID to be used for the route URL generation (in article_path(#article), the routes helper converts #article into #article.id for constructing the /articles/:id URL.
I believe it is the same in ActiveRecord, but anyways in Mongoid, this conversion fails if the model is not persisted (and this is somewhat nice as it prevents the generation of URLs that may not correspond to actual data)
So in my specific case, URL generation crashes as the model is not persisted:
<%= post_url(#post_not_persisted) %>
crashes with
ActionView::Template::Error: No route matches {:action=>"show", :controller=>"posts", :post_id=>#<Post _id: 59b3ea2aaba9cf202d4eecb6 ...
Is there a way I can bypass this limitation only in a very specific scope ? Otherwise I could replace all my resource_path(#model) by resource_path(#model.id.to_s) or better #model.class.name but this doesn't feel like the right situation...
EDIT :
The main problem is
Foo.new.to_param # => nil
# whereas
Foo.new.id.to_s # => "59b528e8aba9cf74ce5d06c0"
I need to force to_param to return the ID (or something else) even if the model is not persisted. Right now I'm looking at refinements to see if I can use a scoped monkeypatch but if you have better ideas please be my guest :-)
module ForceToParamToUseIdRefinement
refine Foo do
def to_param
self.class.name + 'ID'
end
end
end
However I seem to have a small scope problem when using my refinement, as this doesn't bubble up as expected to url_helpers. It works fine when using te refinement in the console though (Foo.new.to_param # => 59b528e8aba9cf74ce5d06c0)
I found a way using dynamic method override. I don't really like it but it gets the job done. I am basically monkeypatching the instances I use during my tests.
To make it easier, I have created a class method example_model_accessor that basically behaves like attr_accessor excepts that the setter patches the #to_param method of the object
def example_model_accessor(model_name)
attr_reader model_name
define_method(:"#{model_name}=") do |instance|
def instance.to_param
self.class.name + 'ID'
end
instance_variable_set(:"##{model_name}", instance)
end
end
Then in my code I can just use
class Testing
example_model_accessor :message
def generate_view_with_unpersisted_data
self.message = FactoryGirl.build(:message)
MessageMailer.created(message).deliver_now
end
end
# views/message_mailer/created.html.erb
...
<%= message_path(#message) %> <!-- Will work now and output "/messages/MessageID" ! -->

Possible to Change Rails Routing Convention?

I'm wondering if it's possible to edit the default Rails routing convention to fetch a specific record based on a field that is not the ID?
For instance, instead of retrieving a specific record based on ID, with the verb/url combination:
GET /users/:id
Retrieve a specific record based on username, with the verb/url combination:
GET /users/:username
I don't see why this would be a problem theoretically, as long as usernames were required to be unique, but I'm having trouble understanding how to implement it based on the Rails Routing Guide.
I have gathered that I will need to add a line to my routes.rb file, to define a singular resource, just prior to:
resources :users
However, I'm having trouble understanding the syntax to accomplish this. Any help in understanding this would be greatly appreciated.
Yes it is possible and they are called Non Restful Routes in the rails documentation
A trivial example is doing the below in your routes.rb
get ':users/:show/:username', controller: "users", action: "show"
and in your UsersController you have a show action that looks like this:
def show
if params[:id].present?
#user = User.find(params[:id])
elsif params[:username].present?
#user = User.find_by(username: params[:username])
end
end
This way you support showing by id and username, if you want do disable support for either of them, modify the if clause as you wish
I think you are looking to change the to_param method like so:
class User < ActiveRecord::Base
def to_param
"#{id} #{name}".parameterize
end
end
This would give the url as: /user/id-name. If you want to get rid of the id before the name it gets a little more complicated. If you were just to remove it, it will more than likely break since ActiveRecord needs the id first for finds.
To get around this I would suggest using FriendlyId gem: https://github.com/norman/friendly_id
There is also a RailsCast showing how to use Friendly_id but its pretty straight forward.
The routes does not care if it is an ID or username.
It is really how you find it in the controller.
Just in the user show controller:
def show
#user = User.find_by_username params[:id]
end

StackOverflow Style Routes with Smart Redirects

StackOverflow seems to have this style of routes for questions:
/questions/:id/*slug
Which is easy enough to achieve, both in routes and to_param.
However, StackOverflow seems to also redirect to that path when just an ID is passed.
Example:
stackoverflow.com/questions/6841333
redirects to:
stackoverflow.com/questions/6841333/why-is-subtracting-these-two-times-in-1927-giving-a-strange-result/
Same goes for any variation of the slug
stackoverflow.com/questions/6841333/some-random-stuff
Will still redirect to the same URL.
My question is: Is this type of redirection typically handled in the controller (comparing the request to the route) or is there a way to do this in routes.rb?
The reason I wouldn't think this possible in the routes.rb file is that typically, you don't have access to the object (so you couldn't get the slug based off the ID, right?)
For anyone interested, Rails 3.2.13 and also using FriendlyID
Ok, so I think I've got this.
I was looking into doing something with middleware, but then decided that's probably not the place for this type of functionality (since we need to access ActiveRecord).
So I ended up building a service object, known as a PathCheck. The service looks like this:
class PathCheck
def initialize(model, request)
#model = model
#request = request
end
# Says if we are already where we need to be
# /:id/*slug
def at_proper_path?
#request.fullpath == proper_path
end
# Returns what the proper path is
def proper_path
Rails.application.routes.url_helpers.send(path_name, #model)
end
private
def path_name
return "edit_#{model_lowercase_name}_path" if #request.filtered_parameters["action"] == "edit"
"#{model_lowercase_name}_path"
end
def model_lowercase_name
#model.class.name.underscore
end
end
This is easy enough to implement into my controller:
def show
#post = Post.find params[:post_id] || params[:id]
check_path
end
private
def check_path
path_check = PathCheck.new #post, request
redirect_to path_check.proper_path if !path_check.at_proper_path?
end
My || in my find method is because in order to maintain resourceful routes, I did something like...
resources :posts do
get '*id' => 'posts#show'
end
Which will make a routes like: /posts/:post_id/*id on top of /posts/:id
This way, the numeric id is primarily used to look up the record, if available. This allows us to loosely match /posts/12345/not-the-right-slug to be redirected to /posts/12345/the-right-slug
The service is written in a universal fashion, so I can use it in any resourceful controller. I have't found a way to break it yet, but I'm open to correction.
Resources
Railscast #398: Service Objects by Ryan Bates
This Helpful Tweet by Jared Fine

Rails - How to fix the generated URL to be a friendly URL

I have models that looks like
search.rb:
id eg: 101
name eg: San Francisco
cars.rb
id
name
The search controller redirects user to cars.
search_controller.rb
if search.search_type=='cars'
redirect_to :controller=>'cars', :action=>'index', :id=>search
end
A query to find list of cars from San Francisco looks like:
http://localhost/cars?id=101
I overrode to_param method in search.rb like:
search.rb
def to_param
normalized_name = name.gsub(' ', '-').gsub(/[^a-zA-Z0-9\_\-\.]/, '')
"#{self.id}-#{normalized_name}"
end
This works to some extent:
It generates URLs that look like:
http://localhost/cars?id=101-San-Francisco
However, I would like is to generate a URL that looks like
http://localhost/cars/San-Francisco
How would I go about doing that?
Do I fix the routes?
Thanks for your help.
This can be tricky if you're not prepared for it. The method that controls how a model shows up in the params is pretty straightforward, as you've identified, but that's only the half of it. Later you'll have to retrieve it, so you need to set up for that:
class Search < ActiveRecord::Base
before_save :assign_slug
def self.from_param(id)
self.find_by_slug(id)
end
def to_param
self.slug
end
protected
def assign_slug
self.slug = self.name.gsub(' ', '-').gsub(/[^\w\-\.]/, '')
end
end
This requires adding a slug column to your Search model in order to make it possible to look up a search by it. It may be a good idea to add an index, possibly a unique one, to help retrieve these later in an efficient manner.
In your controller you don't use find but from_param instead to do the retrieval.
You'll also need to add a custom route that takes this parameter:
match '/cars/:search', :to => 'cars#index', :as => 'cars_search'
As a note you should use the route path generator methods whenever possible because multiple routes may match the same parameters. For instance:
redirect_to cars_search_path(:search => search)

How to implement "short" nested vanity urls in rails?

I understand how to create a vanity URL in Rails in order to translate
http://mysite.com/forum/1 into http://mysite.com/some-forum-name
But I'd like to take it a step further and get the following working (if it is possible at all):
Instead of:
http://mysite.com/forum/1/board/99/thread/321
I'd like in the first step to get to something like this: http://mysite.com/1/99/321
and ultimately have it like http://mysite.com/some-forum-name/some-board-name/this-is-the-thread-subject.
Is this possible?
To have this work "nicely" with the Rails URL helpers you have to override to_param in your model:
def to_param
permalink
end
Where permalink is generated by perhaps a before_save
before_save :set_permalink
def set_permalink
self.permalink = title.parameterize
end
The reason you create a permalink is because, eventually, maybe, potentially, you'll have a title that is not URL friendly. That is where parameterize comes in.
Now, as for finding those posts based on what permalink is you can either go the easy route or the hard route.
Easy route
Define to_param slightly differently:
def to_param
id.to_s + permalink
end
Continue using Forum.find(params[:id]) where params[:id] would be something such as 1-my-awesome-forum. Why does this still work? Well, Rails will call to_i on the argument passed to find, and calling to_i on that string will return simply 1.
Hard route
Leave to_param the same. Resort to using find_by_permalink in your controllers, using params[:id] which is passed in form the routes:
Model.find_by_permalink(params[:id])
Now for the fun part
Now you want to take the resource out of the URL. Well, it's a Sisyphean approach. Sure you could stop using the routing helpers Ruby on Rails provides such as map.resources and define them using map.connect but is it really worth that much gain? What "special super powers" does it grant you? None, I'm afraid.
But still if you wanted to do that, here's a great place to start from:
get ':forum_id/:board_id/:topic_id', :to => "topics#show", :as => "forum_board_topic"
Take a look at the Rails Routing from the Outside In guide.
maybe try something like
map.my_thread ':forum_id/:board_od/:thread_id.:format', :controller => 'threads', :action => 'show'
And then in your controller have
#forum = Forum.find(params[:forum_id])
#board = #forum.find(params[:board_id])
#thread = #board.find(params[:thread_id])
Notice that you can have that model_id be anything (the name in this case)
In your view, you can use
<%= link_to my_thread_path(#forum, #board, #thread) %>
I hope this helps

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