Update Rails column that expects array of strings using AJAX - ruby-on-rails

Question

I'm trying to build a choose your own adventure game using Ruby on Rails and AJAX calls, where the games are user owned resources, and each game has a sentence column, expecting an array of strings.
game {
id: 16,
sentences: ['hello', 'world']
}
The above does not work when passed in as the data on an AJAX patch request (though I get 200 okay), neither does the hail-mary version of:
game {
id: 16,
sentences: 'hello'
}
The rails local server states that sentences are an unpermitted parameter.
started PATCH "/games/21" for ::1 at 2018-03-18 21:11:12 -0400
Processing by GamesController#update as */*
Parameters: {"game"=>{"id"=>"21", "sentences"=>["This is it: the end. You were wrong."]}, "id"=>"21"}
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."token" = $1 LIMIT $2 [["token", "8efb6bc10343a4415f6cbcb16d5184f2"], ["LIMIT", 1]]
Game Load (0.4ms) SELECT "games".* FROM "games" WHERE "games"."user_id" = $1 AND "games"."id" = $2 LIMIT $3 [["user_id", 2], ["id", 21], ["LIMIT", 1]]
Unpermitted parameters: :id, :sentences
(0.1ms) BEGIN
(0.1ms) COMMIT
[active_model_serializers] Rendered GameSerializer with ActiveModelSerializers::Adapter::Json (0.38ms)
Completed 200 OK in 5ms (Views: 0.7ms | ActiveRecord: 0.9ms)
This is maddening, because the parameter is specifically permitted in the controller.
def game_params
params.require(:game).permit(:hope, :wisdom, :user_id, :mnemonic, :sentences)
end
I can't get the sentences column to update using AJAX, though I'd added a method to the game model per this blog post's advice.
class Game < ApplicationRecord
belongs_to :user
def add_sentence(words)
sentences_will_change!
update_attributes sentences: sentences.push(words)
end
end
I can definitely update in the Rails console.
[3] pry(main)> game = Game.where(:id => 16).first
Game Load (0.3ms) SELECT "games".* FROM "games" WHERE
"games"."id" = $1 ORDER BY "games"."id" ASC LIMIT $2 [["id", 16],
["LIMIT", 1]]
=> #<Game:0x007ff420f750f0
id: 16,
hope: nil,
wisdom: nil,
created_at: Mon, 19 Mar 2018 00:33:57 UTC +00:00,
updated_at: Mon, 19 Mar 2018 00:33:57 UTC +00:00,
user_id: 1,
mnemonic: "ah",
sentences: ["hello", "world"]>
[8] pry(main)> game.update(sentences: ['hello', 'world', 'again'])
(0.2ms) BEGIN
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2 [["id", 1], ["LIMIT", 1]]
SQL (0.4ms) UPDATE "games" SET "updated_at" = $1, "sentences" = $2 WHERE "games"."id" = $3 [["updated_at", "2018-03-19 00:37:36.428710"], ["sentences", "{hello,world,again}"], ["id", 16]]
(5.6ms) COMMIT
=> true
[10] pry(main)> game
=> #<Game:0x007ff420f750f0
id: 16,
hope: nil,
wisdom: nil,
created_at: Mon, 19 Mar 2018 00:33:57 UTC +00:00,
updated_at: Mon, 19 Mar 2018 00:37:36 UTC +00:00,
user_id: 1,
mnemonic: "ah",
sentences: ["hello", "world", "again"]>
[11] pry(main)>
Please help? I apologize for the foolishness of the question, I just can't figure out what is going wrong.

Answer 1

One issue appears to be that you don't actually have the :id in your permitted params, yet you are passing an id key in the provided examples.
For the sentences, try mapping the sentences key in your permitted params to an empty array:
def game_params
params.require(:game).permit(:hope, :wisdom, :user_id, :mnemonic, sentences: [])
end
More information in this stack overflow comment: https://stackoverflow.com/a/16555975/2909095