Use # symbol in a rails method name - ruby-on-rails

Is there any way for me to use the '#' symbol in a rails method name? e.g.
def #method_name
end
Rails doesn't seem to like it.
I want to do it to adhere to some external conventions (external to rails).

It can be done like this:
define_method('#test') do
'test'
end
this method then has to be called with:
model.send('#test')
I would not recommend it, since it will be ugly and complicated and that is against the philosophy of ruby. But it can be done.
Kind of like this video: https://www.youtube.com/watch?v=eVpVHGiELf8

What I ended up using:
In my controller:
#job = Job.first
render :json #job.as_json( methods: :#id )
In Job.rb
define_method('#id') do
return url_for( :controller => 'jobs', :action => 'create', :id => id )
end
Now when I render my json i get:
"#id":"http://localhost:3000/jobs?id=1"
Note: #id is to comply with the syntax of json-ld

Related

Custom parameters in URL for show action

I'm working on implementing a SEO-hiarchy, which means that I need to prepend parameters for a show action.
The use-case is a search site where the URL-structure is:
/cars/(:brand)/ => a list page
/cars/(:brand)/(:model_name)?s=query_params => a search action
/cars/:brand/:model_name/:variant/:id => a car show action
My problem is to make the show action URLs work without having to provide :brand, :model_name and :variant as individual arguments. They are always available from as values on the resource.
What I have:
/cars/19330-Audi-A4-3.0-TDI
What I want
/cars/Audi/A4/3.0-TDI/19330
Previously, this was how the routes.rb looked like:
# Before
resources :cars. only: [:show] do
member do
get 'favourize'
get 'unfavourize'
end
Following was my first attempt:
# First attempt
scope '/cars/:brand/:model_name/:variant' do
match ":id" => 'cars_controller#show'
match ":car_id/favourize" => 'cars_controller#favourize', as: :favourize_car
match ":car_id/unfavourize" => 'cars_controller#unfavourize', as: :unfavourize_car
end
This makes it possible to do:
cars_path(car, brand: car.brand, model_name: car.model_name, variant: car.variant)
But that is obviously not really ideal.
How is it possible to setup the routes (and perhaps the .to_param method?) in a way that doesn't make it a tedious task to change all link_to calls?
Thanks in advance!
-- UPDATE --
With #tharrisson's suggestion, this is what I tried:
# routes.rb
match '/:brand/:model_name/:variant/:id' => 'cars#show', as: :car
# car.rb
def to_param
# Replace all non-alphanumeric chars with - , then merge adjacent dashes into one
"#{brand}/#{model_name}/#{variant.downcase.gsub(/[^[:alnum:]]/,'-').gsub(/-{2,}/,'-')}/#{id}"
end
The route works fine, e.g. /cars/Audi/A4/3.0-TDI/19930 displays the correct page. Generating the link with to_param, however, doesn't work. Example:
link_to "car link", car_path(#car)
#=> ActionView::Template::Error (No route matches {:controller=>"cars", :action=>"show", :locale=>"da", :brand=>#<Car id: 487143, (...)>})
link_to "car link 2", car_path(#car, brand: "Audi")
#=> ActionView::Template::Error (No route matches {:controller=>"cars", :action=>"show", :locale=>"da", :brand=>"Audi", :model_name=>#<Car id: 487143, (...)>})
Rails doesn't seem to know how to translate the to_param into a valid link.
I do not see any way to do this with Rails without tweaking either the URL recognition or the URL generation.
With your first attempt, you got the URL recognition working but not the generation. The solution I can see to make the generation working would be to override the car_path helper method.
Another solution could be, like you did in the UPDATE, to override the to_param method of Car. Notice that your problem is not in the to_param method but in the route definition : you need to give :brand,:model_name and :variant parameters when you want to generate the route. To deal with that, you may want to use a Wildcard segment in your route.
Finally you can also use the routing-filter gem which make you able to add logic before and after the url recognition / generation.
For me, it looks like all theses solutions are a bit heavy and not as easy as it should be but I believe this came from your need as you want to add some levels in the URL without strictly following the rails behavior which will give you URL like /brands/audi/models/A3/variants/19930
OK, so here's what I've got. This works in my little test case. Obviously some fixups needed, and I am sure could be more concise and elegant, but my motto is: "make it work, make it pretty, make it fast" :-)
In routes.rb
controller :cars do
match 'cars', :to => "cars#index"
match 'cars/:brand', :to => "cars#list_brand", :as => :brand
match 'cars/:brand/:model', :to => "cars#list_model_name", :as => :model_name
match 'cars/:brand/:model/:variant', :to => "cars#list_variant", :as => :variant
end
In the Car model
def to_param
"#{brand}/#{model_name}/#{variant}"
end
And obviously fragile and non-DRY, in cars_controller.rb
def index
#cars = Car.all
respond_to do |format|
format.html # index.html.erb
format.json { render json: #cars }
end
end
def list_brand
#cars = Car.where("brand = ?", params[:brand])
respond_to do |format|
format.html { render :index }
end
end
def list_model_name
#cars = Car.where("brand = ? and model_name = ?", params[:brand], params[:model])
respond_to do |format|
format.html { render :index }
end
end
def list_variant
#cars = Car.where("brand = ? and model_name = ? and variant = ?", params[:brand], params[:model], params[:variant])
respond_to do |format|
format.html { render :index }
end
end
You just need to create two routes, one for recognition, one for generation.
Updated: use the routes in question.
# config/routes.rb
# this one is used for path generation
resources :cars, :only => [:index, :show] do
member do
get 'favourize'
get 'unfavourize'
end
end
# this one is used for path recognition
scope '/cars/:brand/:model_name/:variant' do
match ':id(/:action)' => 'cars#show', :via => :get
end
And customize to_param
# app/models/car.rb
require 'cgi'
class Car < ActiveRecord::Base
def to_param
parts = [brand,
model_name,
variant.downcase.gsub(/[^[:alnum:]]/,'-').gsub(/-{2,}/,'-'),
id]
parts.collect {|p| p.present? ? CGI.escape(p.to_s) : '-'}.join('/')
end
end
Sample of path helpers:
link_to 'Show', car_path(#car)
link_to 'Edit', edit_car_path(#car)
link_to 'Favourize', favourize_car_path(#car)
link_to 'Unfavourize', unfavourize_car_path(#car)
link_to 'Cars', cars_path
form_for(#car) # if resources :cars is not
# restricted to :index and :show
You want bounded parameters to be passed to url of which some parameters are optional and some of them strictly needs to be present.
Rails guides shows you can have strict as well as optional parameters and also you can give name to particular route in-order to simplify its usage.
Guide on rails routing
bound parameters
Example usage -
In below route,
brand is optional parameter as its surrounded by circular bracket
Also please note there can be optional parameters inside route but they needs to added at last /cars(/:brand)(/:make)(/:model)
match '/cars/(:brand)', :to => 'cars#index', :as => cars
here cars_url will map to index action of cars controller..
again cars_url("Totoya") will route index action of cars controller along-with params[:brand] as Toyota
Show url route can be as below where id is mandatory and others can be optional
match '/cars/:id(/:brand(/:model_name/)(/:variant)', :to => "cars#show", :as => car
In above case, id is mandatory field. Other parameters are optional.
so you can access it like car_url(car.id) or car_url(12, 'toyota') or car_url(12, 'toyota', 'fortuner') or car_url(12, 'toyota', 'fortuner', 'something else)

How to define a controller function that works for instances of any model

Implementing versioning for a Rails app I'd like to have a view that displays all versions of a model with some extra functionality like reverting etc.
I use the paper_trail gem for the versioning.
I know that I could do that by writing a controller function like versions and a view for every model but I'd like to do it for all models at once. This should be possible because the model.versions attribute is always structured identically.
Ideally the URL should look like /pages/testpage/versions while testpage is the page id.
This seems similar to the concept of nested routes in rails.
resources :pages do
resources :versions
end
The problems with nested routes however are:
Needs extra configuration per model
I cannot access the testpage object without knowing of which model it is an instance.
I also wasn't able to find a way to determine the model since the only thing that is provided to my versions controller is the params hash.
I'm completely open to alternative solutions that might not follow my initial ideas.
Write it in your ApplicationController and define it as a helper_method.
For example
class ApplicationController < ActionController::Base
helper_method :current_time
def current_time
Time.now
end
end
Now you can cal current_time everywhere in controllers or views.
Also you can write separate Module/Class and define there your helpers methods. Than you should include this file into your ApplicationController as well
UPD after theme is changed
I didn't think about your actual question. But I can say that your approach is nod the best here.
You should create new resource instead of creating new functionality which will hard to be tested. So create new resource (controller): versions and play around this controller.
For example how it can work:
/versions/pages/132
/versions/comments/1003
How to realize it:
match "/versions/:model/:id", :to => "versions#index"
In your controller:
class VersionsController < ActionController::Base
def index
#object = my_type.find(params[:id])
#versions = #object.versions
end
private
def my_type
params[:model].constantize
end
end
Of course you can change routes the way you want:
match "/:model/:id/versions", :to => "versions#show"
So now your pretty /pages/testpage/versions will work fine for you without any new strange logic.
UPD 2
Imagine you have got this route:
match "/:model/:id/versions", :to => "versions#index", :as => :versions
And this objects:
#page = Page.last
#hotel = Hotel.find(123)
#comment = #page.comments.first
How will we create links for versions:
<%= link_to "Versions of this page", versions_path(:model => #page.class.to_s, :id => #page.id) %>
<%= link_to "Versions of this hotel", versions_path(:model => #hotel.class.to_s, :id => #hotel.id) %>
<%= link_to "Versions of this comment", versions_path(:model => #comment.class.to_s, :id => #comment.id) %>
I would suggest passing a param such as 'type' and stuff the model name there. Then in your controller you can do:
class VersionsController < ApplicationController
def index
model = params[:type].classify.constantize
#obj = model.find(params[:id])
end
end
For your links, you can pass queries to the link_to helper
<%= link_to versions_path(#model, :type => #model.class) %>
Or something along those lines.

Is there a way to check the parameters and decide the routes based on the parameters in rails?

I am looking for a way to decide the routes based on a request parameter.For example i want to have route a request to web controller if it has params[:web] and to iPhone if it has params[:iphone]. Is it possible to do so keeping the names of the routes same but routing them to different controllers/actions depending upon the parameter?
Possible if you define route(or a named route) like below in your routes.rb file
map.connect '/:controller/:action/:platform',:controller => 'some controller name',:action=>'some action'
if you handle this in your action, you can use like params[:platform]
Read more on named routes if you customize more on this. As far as your prob is concerned I hope the above code solves the problem
Expanding on #lakshmanan's answer, you can do this:
Add this to your routes.rb:
map.named_route '/:controller/:action/:platform'
In your views,
<%= link_to "Blah blah", named_route_path(:controller => "some_controller",
:action => "some_action",
:platform => "some_platform")
In your some_controller,
def some_action
if params[:platform] == "web"
#DO SOMETHING
elsif params[:platform] == "iphone"
#DO SOMETHING
else
#DO SOMETHING
end
end
Assuming that there is a very good reason to have one controller accept this action (if there is shared code... move it to a helper method or model, and use the user agent info or named routes to your advantage), check the parameter and redirect to the appropriate controller and action:
def some_action
# some shared code here
if params[:platform] == 'iphone'
redirect_to :controller => 'foo', :action => 'bar'
elsif params[:platform] == 'web'
redirect_to :controller => 'baz', :action => 'baq'
else
# default controller and action here
end
end
If you really really want the named route to map to different controllers, you'll need to hardcode the platform string:
map.connect '/foo/bars/:id/iphone', :controller => 'iphone',:action=>'some_action'
map.connect '/foo/bars/:id/web', :controller => 'web',:action=>'some_action'
UPDATE0
From here, you might want to try map.with_options(:conditions => ... )

Pretty (dated) RESTful URLs in Rails

I'd like my website to have URLs looking like this:
example.com/2010/02/my-first-post
I have my Post model with slug field ('my-first-post') and published_on field (from which we will deduct the year and month parts in the url).
I want my Post model to be RESTful, so things like url_for(#post) work like they should, ie: it should generate the aforementioned url.
Is there a way to do this? I know you need to override to_param and have map.resources :posts with :requirements option set, but I cannot get it all to work.
I have it almost done, I'm 90% there. Using resource_hacks plugin I can achieve this:
map.resources :posts, :member_path => '/:year/:month/:slug',
:member_path_requirements => {:year => /[\d]{4}/, :month => /[\d]{2}/, :slug => /[a-z0-9\-]+/}
rake routes
(...)
post GET /:year/:month/:slug(.:format) {:controller=>"posts", :action=>"show"}
and in the view:
<%= link_to 'post', post_path(:slug => #post.slug, :year => '2010', :month => '02') %>
generates proper example.com/2010/02/my-first-post link.
I would like this to work too:
<%= link_to 'post', post_path(#post) %>
But it needs overriding the to_param method in the model. Should be fairly easy, except for the fact, that to_param must return String, not Hash as I'd like it.
class Post < ActiveRecord::Base
def to_param
{:slug => 'my-first-post', :year => '2010', :month => '02'}
end
end
Results in can't convert Hash into String error.
This seems to be ignored:
def to_param
'2010/02/my-first-post'
end
as it results in error: post_url failed to generate from {:action=>"show", :year=>#<Post id: 1, title: (...) (it wrongly assigns #post object to the :year key). I'm kind of clueless at how to hack it.
Pretty URLs for Rails 3.x and Rails 2.x without the need for any external plugin, but with a little hack, unfortunately.
routes.rb
map.resources :posts, :except => [:show]
map.post '/:year/:month/:slug', :controller => :posts, :action => :show, :year => /\d{4}/, :month => /\d{2}/, :slug => /[a-z0-9\-]+/
application_controller.rb
def default_url_options(options = {})
# resource hack so that url_for(#post) works like it should
if options[:controller] == 'posts' && options[:action] == 'show'
options[:year] = #post.year
options[:month] = #post.month
end
options
end
post.rb
def to_param # optional
slug
end
def year
published_on.year
end
def month
published_on.strftime('%m')
end
view
<%= link_to 'post', #post %>
Note, for Rails 3.x you might want to use this route definition:
resources :posts
match '/:year/:month/:slug', :to => "posts#show", :as => :post, :year => /\d{4}/, :month => /\d{2}/, :slug => /[a-z0-9\-]+/
Is there any badge for answering your own question? ;)
Btw: the routing_test file is a good place to see what you can do with Rails routing.
Update: Using default_url_options is a dead end. The posted solution works only when there is #post variable defined in the controller. If there is, for example, #posts variable with Array of posts, we are out of luck (becase default_url_options doesn't have access to view variables, like p in #posts.each do |p|.
So this is still an open problem. Somebody help?
It's still a hack, but the following works:
In application_controller.rb:
def url_for(options = {})
if options[:year].class.to_s == 'Post'
post = options[:year]
options[:year] = post.year
options[:month] = post.month
options[:slug] = post.slug
end
super(options)
end
And the following will work (both in Rails 2.3.x and 3.0.0):
url_for(#post)
post_path(#post)
link_to #post.title, #post
etc.
This is the answer from some nice soul for a similar question of mine, url_for of a custom RESTful resource (composite key; not just id).
Ryan Bates talked about it in his screen cast "how to add custom routes, make some parameters optional, and add requirements for other parameters."
http://railscasts.com/episodes/70-custom-routes
This might be helpful. You can define a default_url_options method in your ApplicationController that receives a Hash of options that were passed to the url helper and returns a Hash of additional options that you want to use for those urls.
If a post is given as a parameter to post_path, it will be assigned to the first (unnassigned) parameter of the route. Haven't tested it, but it might work:
def default_url_options(options = {})
if options[:controller] == "posts" && options[:year].is_a?Post
post = options[:year]
{
:year => post.created_at.year,
:month => post.created_at.month,
:slug => post.slug
}
else
{}
end
end
I'm in the similar situation, where a post has a language parameter and slug parameter. Writing post_path(#post) sends this hash to the default_url_options method:
{:language=>#<Post id: 1, ...>, :controller=>"posts", :action=>"show"}
UPDATE: There's a problem that you can't override url parameters from that method. The parameters passed to the url helper take precedence. So you could do something like:
post_path(:slug => #post)
and:
def default_url_options(options = {})
if options[:controller] == "posts" && options[:slug].is_a?Post
{
:year => options[:slug].created_at.year,
:month => options[:slug].created_at.month
}
else
{}
end
end
This would work if Post.to_param returned the slug. You would only need to add the year and month to the hash.
You could just save yourself the stress and use friendly_id. Its awesome, does the job and you could look at a screencast by Ryan Bates to get started.

Rails routing model method parameter

I have the route
map.member 'members/:id/:name_url', :controller => 'members', :action => 'show', :requirements => { :id => /\d+/ }
and on my Member model I have a name_url method which takes the name and converts it to lowercase and changes spaces to dashes
the problem is that if I run
link_to "Bill", member
it gives me an "member_url failed to generate from" error
is there a way to achieve that? I was thinking a view helper that generated the link, but I couldn't access that from the controller if I needed to...
Assuming this is the show action of the MembersController
class MembersController
def show
#member = Member.find_by_name("Bill")
end
In app/views/members/show.html.erb, You'll want to use:
<%= link_to #member.name, member_path(#member, :name_url => "something") %>
The problem is the :name_url parameter in your route:
map.member 'members/:id/:name_url', :controller => 'members', :action => 'show', :requirements => { :id => /\d+/ }
When you pass an ActiveRecord object as an option for url_for (which is what link_to does), Rails will implicitly call the model's to_param method. Which unless overridden only returns id the id. You could override to_param, but that won't give you the url you want. Because to_param is used to create the string that replaces id in urls. The best you could do with minimum changes is settle for something like this:
members/:id
where :id is actually :id-:name_url
Really the best option is what Dan McNevin suggests. However if that's too long for you, you can always just make it a helper:
def link_to_member member
link_to member.name, member_url(member, :name_url => member.name)
end
And use it in place of link_to.
link_to "Bill", member => link_to_member member

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