Overriding Rails to_param? - ruby-on-rails

How do I get the to_param method to deliver keyword slugs all the time? I have trouble getting it to work with this route:
map.pike '/auction/:auction_id/item/:id', :controller => 'items', :action => 'show'
Earlier the overridden to_param was working for
'items/1-cashmere-scarf'
but fails with 'auction/123/item/1'
Update:
I'm not sure if the syntax is correct[(edit: it's correct: it works :-)], or even efficient.... but using haml, I found that the following code works to generate the desired link ('auction/:auction_id/item/:id')
- for auction in #auctions.sort{|a, b| a.scheduled_start <=> b.scheduled_start}
-for item in #items
- unless auction.current_auction
... pike_path(auction.auction_id, item)

I'm not sure whether I understand your question. (it's 3:41 AM here)
From what I see, you directly access auction_id method, instead of using pike_path(auction, item) that'd use #to_param.
Also, it might fail for auction/123/item/1 because you haven't changed your controller.
I think it'd be helpful to describe how to get working slugs.
Broadly speaking, if you override #to_param, IDs no longer works. It means, that if you go with slugs, every time polymorpic URL is generated (eg, link_to object, object), it passes to_param's value. It is worth noting that you must change your controller as well.
Personally I think that the best way to generate slugs easily is to use techno-weenie's permalink_fu, adding has_permalink to your model, and then, override to_param. For example
class Auction < ActiveRecord::Base
has_permalink :title, :slug
end
assuming that you have slug, a string field, and want to slugize your title.
You also need to adjust your controller:
class AuctionsController < ApplicationController
def show
#auction = Auction.find_by_slug(params[:id]) || raise(ActiveRecord::RecordNotFound)
respond_to do |format|
format.html # show.html.erb
end
end
Then, you can generate routes, in the views, this way:
link_to #action, #action
By the way, you should NOT sort your actions in the view. The best way is to use named_scope.

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.

Params and selecting the right one

I've got this helper method in my application controller:
def current_team
#current_team ||= Team.find(params[:team_id])
end
Problem is, it works for urls of the format:
/teams/20/members/11
but it doesn't work for:
/teams/20
In order to get it to work for those, I have to change :team_id to be :id.
How can I tidy it up so it 'just works'?
Thanks!
Set instance variables (#current_team) in controllers, never in helpers. It's not what helpers are for.
If you follow this advice, you will naturally use params[:id] in TeamsController, but params[:team_id] in MembersController.
(Some people even go on to say that you shouldn't use helpers at all. For facilitating presentation (custom links, buttons, tables, etc), they propose to use Presenter pattern. But you don't have to listen to them. :))
It is not the best thing to do, but to accomplish that you can do the following:
def current_team
#current_team ||= Team.find(params[:team_id].presence || params[:id])
end
Documentation about the Object.presence method:
http://api.rubyonrails.org/classes/Object.html#method-i-presence
#SergioTulentsev is right, you shall not set instance variables in helpers, only in controllers.
I'm assuming you have other resources besides just Team. Rails is going to use the :id param for all of your resources. You will need to look into customizing the routes for your teams#show action. Easier in Rails 4 than in Rails 3.
Have a look at this post for the gory details: Change the name of the :id parameter in Routing resources for Rails
I wouldn't do params[:team_id] || params[:id], because of course in some controller contexts you'd get an id parameter that represents the id for something other than a Team. Assuming that the /teams/:id route is handled by the TeamsController, then you could do the following (to keep your method in ApplicationController and avoid repeating yourself in different controllers):
def current_team
id = controller_name == "teams" ? params[:id] : params[:team_id]
#current_team ||= Team.find(id)
end
Alternatively, you could change your routes so that the url to show a Team is /teams/:team_id and leave your helper as-is, but that would go against the grain of Rails routing conventions.

Overwrite generated restful url helpers in Rails

Lets say I have a Page resource, and a particular instance has id = 5 and permalink = foobar.
With resources :pages I can use <%= link_to #page.title, #page %> which outputs the url "/pages/5".
How would I make it output "/pages/foobar" instead? Likewise with the edit url... How do I make edit_page_path(#page) output "/pages/foobar/edit"?
UPDATE
Answers so far have said to override to_param in Page.rb which is a great start. +1 to each. But what if I want <%=link_to #page.title, #page%> to output "/:permalink" rather than "/pages/:permalink"?? I'll accept the answer that comes up with that.
You can override the to_param method in your model which will tell Rails what to use instead of your primary key for routing.
For example
class Page
def to_param
"#{self.id}-#{self.title.parameterize}"
end
end
The parameterize call makes your title URL friendly, you might also notice the use of self.id, this is recommended in case you have a duplicate title.
You need to overide to_param method in your model to return the field you want. Here's a blog post with some examples:
You want to use a permalink.
Add this to your model:
class Post
def to_param
"#{id}-{title}"
end
end
This assumes that you have a title.
Once you get this you want to look look up permalink-fu, or it's actually really simple to do your own with an after save:
class Post
before_save :manage_peramlink
def manage_peramlink
permalink = "#{name.gsub(/\s/, '_').gsub(/[^\w-]/, '').downcase}"
end
def to_param
"permalink"
end
end
Make sure you add peramlink as a field to your model.

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

undefined method error, but I defined it!

Rails newbie here, trying to get a new controller working.
When I try to show ann existing instance, I get an undefined method error on a helper method.
Code follows.
Any idea why getRecipes would be undefined?!
Controller:
def show
id = params[:id]
recipe_ids = ConcreteMenu.getRecipes(id)
respond_to do |format|
format.html
end
end
Model
require 'json/objects'
class ConcreteMenu < ActiveRecord::Base
has_many :menu_recipes
has_many :recipes, :through => :menu_recipes
belongs_to :menu
def self.getRecipes(id)
recipes = MenuRecipe.find(:all, :conditions => {:concrete_menu_id => id}, :select => 'id')
end
end
It would help if you pasted the error text, because your explanation leaves a lot of possibilities for what could be wrong. BUT, there is an easier way to get what you want. The value of defining "has_many" relationships is that instead of calling a class method and passing the id of a concrete menu to get its associated recipes, you can just do this:
def show
#concrete_menu = ConcreteMenu.find(params[:id], :include => :recipes)
end
Now you'll have the menu object, and #concrete_menu.recipes returns an array of recipes you need. This feature is already built in, no need to reinvent the wheel.
Also, I noticed you were attempting to collect id's in the controller instead of the objects themselves. This suggests that you're going back and actually retrieving the records in the view itself. This is less efficient, and more difficult to troubleshoot when things go wrong. My example above will do what you need in a better (and more rails-accepted) way.
As you have it defined there, it should be available. Is there a chance you have something else called ConcreteMenu defined, but in a different context?
To be sure you're calling the correct one, where there may be ambiguity, you can refer to the top-level class:
recipe_ids = ::ConcreteMenu.getRecipes(id)
The other way to check that the method is defined correctly via script/console:
ConcreteMenu.methods.grep(/getRecipe/)
# => ["getRecipes"]
This is presuming, of course, you're having trouble with the getRecipes method. There's a possibility you're mistaking how controller variables are passed to the view:
def show
#id = params[:id]
#recipe_ids = ConcreteMenu.getRecipes(#id)
respond_to do |format|
format.html
end
end
Any instance variables defined (#...) will be available within the context of the view, but any local variables will no longer be defined as they are out of scope.

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