Hi, I’m currently working with ActiveResource and I have some troubles
with it.
I have two models on the server side, Artist and Song
Songs: belong_to :artist and Artist: has_many :songs
I also have two controllers methods :
A method songs in the ArtistsController that return his songs
and a list_by_artist in the SongsController that return all the songs
for an artist.
All of this is Restful.
map.resources :artists, :member => {:songs => :get}
map.resources :songs, :collection => {:list_by_artist => :get}
I know that these two methods does the same thing and I will keep only
one of them at the end but :
I wan’t to be able to retrieve all the songs of an artist in the
client side (with ActiveResource) as Songs objects
I can do :
Artist.find(1).get(:songs) to retrieve an Array
but
Artist.find(1).find(:songs) gives me a NoMethodError for the find
method
I can also do
Song.get(:list_by_artist, :id => 1) #again an Array…
but
Song.find(:list_by_artist, :id => 1) gives me :
ArgumentError: expected an attributes Hash, got []
from /var/lib/gems/1.8/gems/activeresource-2.1.0/lib/
active_resource/base.rb:883:in load' from /var/lib/gems/1.8/gems/activeresource-2.1.0/lib/ active_resource/base.rb:639:ininitialize’
…
Looks like Rails try to instanciate a record where it should
instantiate a collection.
Is there any way to solve this ?
Is my method buggy, or is it Rails ?
Artist.find(1).get(:songs) to retrieve an Array
but
Artist.find(1).find(:songs) gives me a NoMethodError for the find
method
err… you could do
@artist = Artist.find(1)
@songs = @artist.songs
you get a NoMethodError because you are trying to call find on a Artist
object
Song.find(:list_by_artist, :id => 1) gives me :
ArgumentError: expected an attributes Hash, got []
from /var/lib/gems/1.8/gems/activeresource-2.1.0/lib/
active_resource/base.rb:883:in load' from /var/lib/gems/1.8/gems/activeresource-2.1.0/lib/ active_resource/base.rb:639:ininitialize’
…
if you want to get the songs from a artist you can do like i said before
or:
@songs = Song.find_by_artist_id(1) # guess you have a artist_id on songs
if I’m not mistaken this is the right way…
if you want to get the songs from a artist you can do like i said before
or:
@songs = Song.find_by_artist_id(1) # guess you have a artist_id on songs
if I’m not mistaken this is the right way…
Sorry, to retrieve all the songs from an artist you call
@songs = Song.find_all_by_artist_id(1) # guess you have a artist_id on
songs
if you use the find_by_artist_id, you would get just one song instead of
all of them
Will this work even though the two models are ActiveResource based? I
didn’t think it provided you with the finder methods on ActiveResource
models.
Ryan B. wrote:
Will this work even though the two models are ActiveResource based? I
didn’t think it provided you with the finder methods on ActiveResource
models.
Ops… that’s right it won’t work… my mistake…
I’m a bit confused. Why not just say:
artist.songs (that’ll return all the songs for a given artist
object) or
Song.find_by_artist_id(1) which will return all the songs where
artist ID is one
If you’re not able to do that in script/console then your models are
not defined correctly.
Artist < ActiveRecord::Base should have “has_many :songs” and
Song < ActiveRecord::Base should have “belongs_to :artist”
I think ActiveRecord is pretty tight - I haven’t experienced any bugs
(well just one but it was some really far out funky thing). The stuff
you are doing is run-of-the-mill every day AcitveRecord.
If you’re wanting to do it REST style then you need to define some
nested routes. That’ll give you something like /artists/1/songs/4
for song with ID of 4, which belongs to artist 1. That has more to do
with ActiveResource than ActiveRecord.
Nicholas
Yes all this find_by_*** stuff and even
@artist = Artist.find(1)
@songs = @artist.songs
doesn’t work just cause it should not wok, I don’t want to be able to
do anything on my “server” models, just the stuff that the RESTFUL
webservice “describe” (that means that I have to call URL, not server
models methods).
The right way to do this is the
Artist.find(1).get(:songs)
or
Song.get(:list_by_artist, :id => 1)
but as I say previously, this return an Array.
I’m not sure that
Artist.find(1).find(:songs)
should work (find is not defined for an ActiveResource object)
but
Song.find(:list_by_artist, :id => 1)
should work according to the doc, but it just doesn’t work according
to my test 
Any other idea ?
You obviously didn’t quite read the first email, or the title of this
thread.
He’s using ActiveResource models, not ActiveRecord. The dynamic
finders you so trumpet are not available to him!
Please read thoroughly next time!
So nobody has any idea ?
Should I submit a bug in Lighthouse ?
On Mon, Jul 21, 2008 at 7:36 AM, Ryan B. [email protected]
wrote:
Artist < ActiveRecord::Base should have “has_many :songs” and
webservice “describe” (that means that I have to call URL, not server
I’m not sure that
or:
songs
–
Jonathan Blanchet
C.V. : http://cv.blogbangbang.com/
This is very helpful, I was getting the same error about a month ago
and just gave up. Thanks for giving me a renewed interest and idea to
tackle the problem
Ok so I’ll answer my own question 
In fact, the
Person.find(:managers)
example written by Ryan daigle and DHH doen’t work (anymore?)
http://ryandaigle.com/articles/2007/4/26/what-s-new-in-edge-rails-activeresource-gets-custom-methods
You have to write
Person.find(:all, :from => :managers)
and if you wants some params :
Person.find(:all, :from => :managers, :params => {:office =>
“Chicago”})
this will make a call to
http://webservice_site/persons/managers.xml?office=Chicago
and returns the result as real ActiveResource objects !
Hope that can help anyone
On Jul 21, 10:09 am, “jonathan Blanchet” [email protected]