Help with understanding RESTful routes

Rails
1

Hi,

I’m planning a new application and after all I’ve read a RESTful rails
app
seems to be perfect for the job. But since a few days I’m struggling
with
routing… here’s my simple test. If would be great if someone could
enlighten me…

Three models: Person <----> Employment <----> Company

class Person < ActiveRecord::Base
has_many :employments
has_many :companies, :through => :employments
end

class Employment < ActiveRecord::Base
belongs_to :company
belongs_to :person
end

class Company < ActiveRecord::Base
has_many :employments
has_many :people, :through => :employments
end

I’ve created the models and generated all three controllers with the
scaffold_resource generator.

  1. I would like the following URLs to work correct:

http://localhost:3000/companies
http://localhost:3000/companies/2
http://localhost:3000/people

This is quite simple. I just added two routes:
map.resources :companies
map.resources :people

  1. Now I would like the following to work:
    http://localhost:3000/companies/1/people

This should show me a list with all people assigned (via Employment) to
company with ID=1.

This route seem’s like a starting point:
map.resources :companies do |company|
company.resources :people
end

Now I think I must enhance the CompaniesController. Changing my
controller to
something like this…

def index
@companies = Person.find(params[:person_id]).companies
end

… seems to work, but of course http://localhost:3000/companies stopped
working.

Do I really have to change my index method again to decide between
“person_id
is set, look for Person.find(:person_id).companies” and “no person_id,
so do
a Company.find(:all)”?

What happens when my application is growing and there are many models
connected with my Person-model? Isn’t there some of this
rails-magic-glue
that’s doing the dirty work?

I also thought that calling something like
http://localhost/companies/42/people/new would automagically create the
association between the Company with ID 42 and the newly entered
Person…?

Regards,
Timo

2

Hi,

looking at your models I’d say you need 2 more resources: employees
and employers.

NOTE: I am not saying you need 2 more models. I’m saying 2 more
resources.

See below:

On 15-Mar-07, at 2:06 PM, Timo S. wrote:

Three models: Person <----> Employment <----> Company

http://localhost:3000/companies
This should show me a list with all people assigned (via
Employment) to
company with ID=1.

This route seem’s like a starting point:
map.resources :companies do |company|
company.resources :people
end

map.resources :companies do |company|
company.resources :employees
end

map.resources :people do |person|
person.resources :employers
end

employees_controller and employers_controller can then deal with the
logic of your Employment model according to their specific needs
without resorting to torturous logic like “I’m the companies
controller but if I have a person_id them I’m displaying a specific
person’s company”. And, of course, you can use shared partials to
keep your views dry.

HTH,
Trevor

3

Timo,

Maybe this will get your mind focused toward the correct solution:

http://localhost:3000/employments/new

Take a look at the following set of slides. Page down until you see a
bright orange slide labeled “Constraints are liberating.” Then read
though the next few slides.
http://www.loudthinking.com/lt-files/worldofresources.pdf

On Mar 15, 5:06 pm, Timo S. [email protected]

4

Hi,

looking at your models I’d say you need 2 more resources: employees
and employers.

Well, after reading the rest of your post, this seems damn logical.
Thanks for
the enlightment. :slight_smile:

without resorting to torturous logic like “I’m the companies
controller but if I have a person_id them I’m displaying a specific
person’s company”. And, of course, you can use shared partials to
keep your views dry.

I think this is the way to go, although I hoped for a little bit more
magic…

Regards,
Timo