问题
I have a functioning Rails 3 app that uses has_many :through associations which is not, as I remake it as a Rails 4 app, letting me save ids from the associated model in the Rails 4 version.
These are the three relevant models are the same for the two versions.
Categorization.rb
class Categorization < ActiveRecord::Base
belongs_to :question
belongs_to :category
end
Question.rb
has_many :categorizations
has_many :categories, through: :categorizations
Category.rb
has_many :categorizations
has_many :questions, through: :categorizations
In both apps, the category ids are getting passed into the create action like this
\"question\"=>{\"question_content\"=>\"How do you spell car?\", \"question_details\"=>\"blah \", \"category_ids\"=>[\"\", \"2\"],
In the Rails 3 app, when I create a new question, it inserts into questions table and then into the categorizations table
SQL (82.1ms) INSERT INTO \"questions\" (\"accepted_answer_id\", \"city\", \"created_at\", \"details\", \"province\", \"province_id\", \"question\", \"updated_at\", \"user_id\") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?) [[\"accepted_answer_id\", nil], [\"city\", \"dd\"], [\"created_at\", Tue, 14 May 2013 17:10:25 UTC +00:00], [\"details\", \"greyound?\"], [\"province\", nil], [\"province_id\", 2], [\"question\", \"Whos\' the biggest dog in the world\"], [\"updated_at\", Tue, 14 May 2013 17:10:25 UTC +00:00], [\"user_id\", 53]]
SQL (0.4ms) INSERT INTO \"categorizations\" (\"category_id\", \"created_at\", \"question_id\", \"updated_at\") VALUES (?, ?, ?, ?) [[\"category_id\", 2], [\"created_at\", Tue, 14 May 2013 17:10:25 UTC +00:00], [\"question_id\", 66], [\"updated_at\", Tue, 14 May 2013 17:10:25 UTC +00:00]]
In the rails 4 app, after it processes the parameters in QuestionController#create, I\'m getting this error in the server logs
Unpermitted parameters: category_ids
and the question is only getting inserted into the questions table
(0.2ms) BEGIN
SQL (67.6ms) INSERT INTO \"questions\" (\"city\", \"created_at\", \"province_id\", \"question_content\", \"question_details\", \"updated_at\", \"user_id\") VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING \"id\" [[\"city\", \"dd\"], [\"created_at\", Tue, 14 May 2013 17:17:53 UTC +00:00], [\"province_id\", 3], [\"question_content\", \"How\'s your car?\"], [\"question_details\", \"is it runnign\"], [\"updated_at\", Tue, 14 May 2013 17:17:53 UTC +00:00], [\"user_id\", 12]]
(31.9ms) COMMIT
Although I am not storing the category_ids on the Questions model, I set category_ids as a permitted parameter in the questions_controller
def question_params
params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids)
end
Can anyone explain how I\'m supposed to save the category_ids? Note, there is no create action in the categories_controller.rb of either app.
These are the three tables that are the same in both apps
create_table \"questions\", force: true do |t|
t.text \"question_details\"
t.string \"question_content\"
t.integer \"user_id\"
t.integer \"accepted_answer_id\"
t.datetime \"created_at\"
t.datetime \"updated_at\"
t.integer \"province_id\"
t.string \"city\"
end
create_table \"categories\", force: true do |t|
t.string \"name\"
t.datetime \"created_at\"
t.datetime \"updated_at\"
end
create_table \"categorizations\", force: true do |t|
t.integer \"category_id\"
t.integer \"question_id\"
t.datetime \"created_at\"
t.datetime \"updated_at\"
end
Update
This is the create action from the Rails 3 app
def create
@question = Question.new(params[:question])
respond_to do |format|
if @question.save
format.html { redirect_to @question, notice: \'Question was successfully created.\' }
format.json { render json: @question, status: :created, location: @question }
else
format.html { render action: \"new\" }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end
This is the create action from the Rails 4 app
def create
@question = Question.new(question_params)
respond_to do |format|
if @question.save
format.html { redirect_to @question, notice: \'Question was successfully created.\' }
format.json { render json: @question, status: :created, location: @question }
else
format.html { render action: \"new\" }
format.json { render json: @question.errors, status: :unprocessable_entity }
end
end
end
This is the question_params method
private
def question_params
params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids)
end
回答1:
This https://github.com/rails/strong_parameters seems like the relevant section of the docs:
The permitted scalar types are String, Symbol, NilClass, Numeric, TrueClass, FalseClass, Date, Time, DateTime, StringIO, IO, ActionDispatch::Http::UploadedFile and Rack::Test::UploadedFile.
To declare that the value in params must be an array of permitted scalar values map the key to an empty array:
params.permit(:id => [])
In my app, the category_ids are passed to the create action in an array
"category_ids"=>["", "2"],
Therefore, when declaring strong parameters, I explicitly set category_ids to be an array
params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids => [])
Works perfectly now!
(IMPORTANT: As @Lenart notes in the comments, the array declarations must be at the end of the attributes list, otherwise you'll get a syntax error.)
回答2:
If you want to permit an array of hashes(or an array of objects from the perspective of JSON)
params.permit(:foo, array: [:key1, :key2])
2 points to notice here:
arrayshould be the last argument of thepermitmethod.- you should specify keys of the hash in the array, otherwise you will get an error
Unpermitted parameter: array, which is very difficult to debug in this case.
回答3:
It should be like
params.permit(:id => [])
Also since rails version 4+ you can use:
params.permit(id: [])
回答4:
If you have a hash structure like this:
Parameters: {"link"=>{"title"=>"Something", "time_span"=>[{"start"=>"2017-05-06T16:00:00.000Z", "end"=>"2017-05-06T17:00:00.000Z"}]}}
Then this is how I got it to work:
params.require(:link).permit(:title, time_span: [[:start, :end]])
回答5:
I can't comment yet but following on Fellow Stranger solution you can also keep nesting in case you have keys which values are an array. Like this:
filters: [{ name: 'test name', values: ['test value 1', 'test value 2'] }]
This works:
params.require(:model).permit(filters: [[:name, values: []]])
来源：https://stackoverflow.com/questions/16549382/how-to-permit-an-array-with-strong-parameters