Why is my rails controller rolling back my ajax commit? - ruby-on-rails

Question

I am having a mysterious problem with the controller receiving my ajax request but not saving it in the database. In my server log I see:
Started POST "/collection_maps" for 127.0.0.1 at 2014-07-07 07:14:04 -0600
Processing by CollectionMapsController#create as */*
Parameters: {"collection_id"=>"2", "manufacturer_id"=>"1", "package_id"=>"14"}
(0.1ms) begin transaction
(0.1ms) rollback transaction
Rendered collection_maps/create.js.erb (1.9ms)
Completed 200 OK in 19.2ms (Views: 4.8ms | ActiveRecord: 0.2ms)
127.0.0.1 - - [07/Jul/2014 07:14:04] "POST /collection_maps HTTP/1.1" 200 - 0.0627
The response I receive in the browser from my create.js.erb file indicates the parameters are null -- but as you can see above, they're clearly there.
(The response comes only as text, the browser doesn't execute the code, but that's another problem. I think.)
// Create a list of errors
var errors = $('<ul />');
errors.append('<li>Package can\'t be blank</li>');
errors.append('<li>Manufacturer can\'t be blank</li>');
errors.append('<li>Collection can\'t be blank</li>');
// Display errors on form
$("#collection-response").html(errors).show();
When I try to create the record in the console, using the same parameters, it works:
irb(main):006:0> c = CollectionMap.new("collection_id"=>"2", "manufacturer_id"=>"1", "package_id"=>"12")
=> #<CollectionMap id: nil, package_id: 12, manufacturer_id: 1, collection_id: 2, created_at: nil, updated_at: nil>
irb(main):007:0> c.save
(0.1ms) begin transaction
SQL (5.7ms) INSERT INTO "collection_maps" ("collection_id", "created_at", "package_id", "manufacturer_id", "updated_at") VALUES (?, ?, ?, ?, ?) [["collection_id", 2], ["created_at", Mon, 07 Jul 2014 06:38:47 UTC +00:00], ["package_id", 12], ["manufacturer_id", 1], ["updated_at", Mon, 07 Jul 2014 06:38:47 UTC +00:00]]
(1.2ms) commit transaction
=> true
irb(main):008:0> c
=> #<CollectionMap id: 6, package_id: 12, manufacturer_id: 1, collection_id: 2, created_at: "2014-07-07 06:38:47", updated_at: "2014-07-07 06:38:47">
I thought maybe it had something to do with CRSF protection (though I don't have user sessions) so I added a skip_filter. Here's my controller code:
class CollectionMapsController < ApplicationController
respond_to :js, :html
skip_before_filter :verify_authenticity_token
# POST /collection_maps
# POST /collection_maps.xml
def create
#collection_map = CollectionMap.new(params[:collection_map])
flash[:notice] = "Collection map successfully added" if #collection_map.save
respond_with( #collection_map, :layout => !request.xhr?)
end
Here's my ajax code:
$.ajax({ url: '<%="#{collection_maps_path}"%>',
type: 'POST',
beforeSend: function(xhr) {xhr.setRequestHeader('X-CSRF-Token',
'<%="#{form_authenticity_token}"%>')},
dataType: "js",
data: {'collection_id' : this.value,
'manufacturer_id' : $("#remedy_manufacturer_id option:selected").val(),
'package_id' : $("#remedy_package_id option:selected").val()},
});
And finally, my model:
class CollectionMap < ActiveRecord::Base
belongs_to :manufacturer
belongs_to :package
belongs_to :collection
validates_presence_of :package_id, :manufacturer_id, :collection_id
attr_protected :created_at
attr_protected :updated_at
attr_accessible :package_id, :manufacturer_id, :collection_id
end
I am totally baffled, so help would be much appreciated.
UPDATE: The reason my browser was not executing the javascript returned by the controller was because I had dataType: "js" in the ajax request. Should be dataType: "script". Be careful where you cut and paste from!

Answer 1

Your AJAX request is sending back the three parameters you need, but your controller action is looking for them nested below a :collection_map key. You can change your controller to this:
def create
#collection_map = CollectionMap.new(params)
flash[:notice] = "Collection map successfully added" if #collection_map.save
respond_with( #collection_map, :layout => !request.xhr?)
end
Or change your AJAX request to this:
$.ajax({ url: '<%="#{collection_maps_path}"%>',
type: 'POST',
beforeSend: function(xhr) {xhr.setRequestHeader('X-CSRF-Token',
'<%="#{form_authenticity_token}"%>')},
dataType: "js",
data: {'collection_map': {'collection_id' : this.value,
'manufacturer_id' : $("#remedy_manufacturer_id option:selected").val(),
'package_id' : $("#remedy_package_id option:selected").val()}},
});
Changing the AJAX request is probably preferable; nesting the parameters below a single key is more "Rails-like"/idiomatic.

Answer 2

you are also mixing attr_accessible and attr_protected. Choose One. Or if this is a newer Rails (4.0 + ) project, use the the new params methodology by creating a method like 'collection_map_params' for 'protection' in your CollectioMapsController.