Passing parameters with RESTful urls


I'm using RESTful urls for a person model, such as edit_person_path
and new_person_path. The problem I am having is that I want to pass
some parameters with some of these urls:
I want to pass the current person id to the new person_url, as the new
person is to be a child of the current person. I keep getting an error
when I try

Is this because it is not a POST request?

I would also like to set an instance variable in the new action
@person_id =

I want this to then be passed with the form to the create action. In
the form, I am using the new Rails 2.x syntax:
% form_for @person do |f| %>

In the past I used:
<% form_for(:person, :url => create_person_path(:person_id =>
@person_id)) do |f| %>

How would I first of all make this variable available to the new
action and then pass it on to the create action?



when I try

if you use additional parameters you must give them names like:

new_person_path(:person_id =>

to hand additional parameters with forms i would use a hidden_field

Thanks Thorsten,

I can now pass an extra parameter with my new_person_path.

I could now use a hidden form field, as suggested, but in the past, I
have simply been able to pass extra parameters through the form_for
tag like so:

<% form_for(:person, :url => create_person_path(:person_id =>
@person_id)) do |f| %>

Is there anyway I can still do this as it would be preferable to using
a hidden form field?

I've tried:

<% form_for @person, :person_id => @person_id do |f| %>

but it doesn't work. It seems that I am simply trying to do the same
thing as I did with the new_page path. Unfortunately there is now a
bit of 'rails magic' going on in the background. It is making it a
'put' request because it is in the 'new' view. How do I add extra
parameters to these 'magic' form_fors?


I believe this should work:

form_for :person, :url=>people_path(:person_id=>@person_id), :method=>:post

This was the actual code that worked (it needed the singular
person_path rather than the plural people_path, and this required a
parameter of @person):

<% form_for @person, :url=>person_path(@person, :person_id =>
@person_id),:html => { :method => :post } do |f| %>

Thanks for all the help everybody,



Are you using acts_as_tree for this?

acts_as_tree allows you to define parent_id, rather than people_id, and then defines methods on your objects like #children to see all the children of a certain object.

Hi Ryan,

I'm actually using the betternestedset plugin. This has the same
methods as acts_as_tree, I'm over-riding the column name parent_id
with people_id, so it still works.

The difference with this plugin is that you can't just do
Person(1), you need to create a new peson, then move it
to be a child of a certain person. This means that the parent's id
needs to be continually passed through the new and create process (as
far as I can see.....)

The method I mentioned above is the best way I could find of doing
this. Have you got any alternatives?



But will this nested route work recursively? What if I wanted to do

Abraham is a parent of homer who is a parent of Bart, could I do:

parents/abraham/children/homer/children/new ???

I like the sound of using nested RESTful routes and will have a look
at them. Could I nested routes with the same name, ie:
map.resources :people do |parent|
parent.resources :people

It would also be good if I could get rid of having to put 'people' in
front of all the urls, so I could just use paths like:

This way, the url shows the family tree...

Thanks again Ryan,


No you can’t do that unfortunately. I think with your plugin you should already have a method to get the ancestors of a perosn.

cheers Ryan - yest I've used the Person.ancestors method to then
create a path that can be used to create an url that looks like a
family tree. This involved over-riding the RESTful urls using: '*family', :controller => 'people', :action => 'show'

This gives you an array called 'family' with the whole family tree and
works quite nicely!