Rails permit nested array - ruby-on-rails

Question

I am trying to use accepts_nested_attributes_for in conjunction with a has_many association and having a lot of trouble...
Here is a simplified version of my user.rb:
class User < ActiveRecord::Base
...
has_many :user_permissions
accepts_nested_attributes_for :user_permissions
...
end
My user_permission.rb:
class UserPermission < ActiveRecord::Base
belongs_to :user
...
end
And my users_controller.rb:
class UsersController < ApiController
...
def update
#user.assign_attributes user_params
if #user.save
render partial: 'user', locals: { user: #user }
else
render json: {errors: #user.errors}.to_json, status: 500
end
end
...
private
def user_params
params.require(:user).permit(:first_name, :last_name, user_permissions_attributes: [ :user_id, :resource_id, :can_read, :can_update, :can_create, :can_delete ])
end
end
I am referencing this rails documentation on how to use accepts_nested_attributes_for with Strong Parameters.
However, when I 'puts user_params' from inside the users_controller this is all I see (no reference to the user_permissions):
{"first_name"=>"Joe", "last_name"=>"Shmoe"}
Here is an example of JSON I am submitting to the server (via angular $resource):
{
"id": 10,
"first_name": "Joe",
"last_name": "Shmoe",
"user_permissions": [
{
"organization_resource_id": 20,
"user_id": 10,
"can_update": true,
"can_read": true
},
{
"organization_resource_id": 21,
"user_id": 10,
"can_create": true,
"can_read": true
}
],
}
Which returns this JSON:
{
"id": 10,
"first_name": "Joe",
"last_name": "Shmoe",
"user_permissions": [],
}
I am fairly confident this is an issue in my rails layer, but just for reference here is the angular User.js service I created to perform this RESTful interaction with the server:
angular.module('slics').service('User', [
'$resource', function($resource) {
return $resource('/api/users/:id', {
id: '#id'
}, {
update: {
method: 'PUT',
isArray: false
}
});
}
]);
Really not sure what I am missing here. It does not seem like it should be this difficult to submit nested attributes... but the more research I do the more I realize this does seem to be a pretty common Rails frustration.
Please feel free to comment if any additional context/information would be useful to include in my problem description to help troubleshoot this problem and I would be happy to provide it!

Answer 1

Strong params expects user_permissions_attributes, and you're submitting user_permissions.
Strong params is separate from accepts_nested_attributes_for (in fact, it has nothing to do with it), so however you define your require!/permit calls is exactly how your attributes should be submitted.
ProTip: To save you some future frustration, if you plan on updating through accepts nested attributes, you probably want to permit :id as well.

Answer 2

Well, you post an array of hashes, not a hash.
So this code
user_permissions_attributes: [ :user_id, :resource_id, :can_read, :can_update, :can_create, :can_delete ]
will permit such structure
{
"id": 10,
"first_name": "Joe",
"last_name": "Shmoe",
"user_permissions_attributes": [
"organization_resource_id": 20,
"user_id": 10,
"can_update": true,
"can_read": true
]
}
Try to whitelist all params at "user_permissions"
user_permissions_attributes: []
Or check out this article, to learn how to build advanced whitelists with StrongParams
http://patshaughnessy.net/2014/6/16/a-rule-of-thumb-for-strong-parameters

Answer 3

user_permissions_attributes: [ :user_id, :id, :can_read, :can_update, :can_create, :can_delete ]) permit :id and submitting hashes with index value..
JSON format submitting to the serve
"user": {
"id": 10,
"first_name": "Joe",
"last_name": "Shmoe",
"user_permissions": {
"0": {
"id": 20,
"user_id": 10,
"can_update": true,
"can_read": true
},
"1": {
"id": 21,
"user_id": 10,
"can_create": true,
"can_read": true
}
}
}