获取ArgumentError（错误的参数数量）错误但不知道Rails中缺少哪些参数？

Question

I know this is such a common error in Rails but I cannot figure out what params are missing.

I'm patching a fetch request from React to Rails to Update Sighting which is a join table to Animal and User . The sighting model has a has_one_attached using Active Storage. This is called image and does not have to be an attribute of Sighting table but from what I understand does need to be in strong_params.

Here's the React fetch:

  editSighting = (title, body, animalId, sightingId) => {

    fetch(`http://localhost:9000/api/v1/sightings/${sightingId}`, {
      method: "PATCH",
      headers: {
        "Content-Type": "application/json",
        "Accept": "application/json",
        "Authorization": localStorage.getItem("token")

      },
      body: JSON.stringify({
        title: title,
        body: body,
        likes: this.state.likes,
        animal_id: animalId,
        user_id: this.state.currentUser.id
    })
  })
  .then(r => r.json())
  .then(newSighting => {
    this.setState({ sightings: [...this.state.sightings, newSighting ]})
  })

Here's the SightingController :

class Api::V1::SightingsController < ApplicationController
  before_action :find_sighting, only: [:update, :show, :destroy]

  def index
   @sightings = Sighting.all
   render json: @sightings
  end




  def create
    @sighting = Sighting.new(sighting_params)
    @sighting.image.attach(params[:sighting][:image])
     if @sighting.save && @sighting.image.attached
      render json: @sighting, status: :accepted
    else
      render json: { errors: @sighting.errors.full_messages }, status: :unprocessible_entity
    end
  end


  def update
    # if curr_user.id == @sighting.user_id
   @sighting.update(sighting_params)
   if @sighting.save
     render json: @sighting, status: :accepted
   else
     render json: { errors: @sighting.errors.full_messages }, status: :unprocessible_entity
   end
  end


  def destroy
    if curr_user.id == @sighting.user_id
      @sighting.image.purge_later
      @sighting.delete
      render json: "sighting deleted"
    else
      render json: { errors: "You are not authorized to delete"}
    end
  end


  private

  def sighting_params
   params.require[:sighting].permit(:title, :body, :likes, :image, :user_id, :animal_id)
  end

  def find_sighting
   @sighting = Sighting.find(params[:id])
  end
end

the model Sighting

class Sighting < ApplicationRecord
  has_one_attached :image

  def image_filename
    self.image.filename.to_s if self.image.attached?
  end

  def image_attached?
    self.image.attached?
  end

  belongs_to :user
  belongs_to :animal
  has_many :comments, :as => :commentable, dependent: :destroy

end

and ModelSerializer :

class SightingSerializer < ActiveModel::Serializer
  include Rails.application.routes.url_helpers


  attributes :id, :title, :body, :likes, :image, :created_at

 belongs_to :animal
 belongs_to :user
 has_many :comments, :as => :commentable, dependent: :destroy

 def image
   rails_blob_path(object.image, only_path: true) if object.image.attached?
 end

end

I was able to update a sighting via Rails console no problem with just updating the title .

The Rails error:

Completed 500 Internal Server Error in 7ms (ActiveRecord: 6.2ms)



ArgumentError (wrong number of arguments (given 0, expected 1)):

app/controllers/api/v1/sightings_controller.rb:48:in `sighting_params'
app/controllers/api/v1/sightings_controller.rb:25:in `update'

And here's an update run from console:

2.6.0 :017 > Sighting.first.update(title: "In NYC?? What a surprise!") 
  Sighting Load (0.6ms)  SELECT  "sightings".* FROM "sightings" ORDER BY "sightings"."id" ASC LIMIT $1  [["LIMIT", 1]]
   (0.2ms)  BEGIN
  User Load (0.4ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", 39], ["LIMIT", 1]]
  Animal Load (0.4ms)  SELECT  "animals".* FROM "animals" WHERE "animals"."id" = $1 LIMIT $2  [["id", 231], ["LIMIT", 1]]
  Sighting Update (0.6ms)  UPDATE "sightings" SET "title" = $1, "updated_at" = $2 WHERE "sightings"."id" = $3  [["title", "In NYC?? What a surprise!"], ["updated_at", "2019-03-26 16:23:11.098248"], ["id", 7]]
   (2.2ms)  COMMIT
 => true 

Answer 1

I'll include the syntax error in your controller's params that was fixed by the commenters:

params.require(:sighting)...

Second of all, you need to pass your JSON with that sighting param wrapping them up because it is required by your controller:

fetch(`http://localhost:9000/api/v1/sightings/${sightingId}`, {
   method: "PATCH",
   headers: {
     "Content-Type": "application/json",
     "Accept": "application/json",
     "Authorization": localStorage.getItem("token")
   },
   body: JSON.stringify({
     sighting: {
        title: title,
        body: body,
        likes: this.state.likes,
        animal_id: animalId,
        user_id: this.state.currentUser.id
    }
})

That will give you the correct params when you PUT to your controller. Otherwise, it'll not save your values because they will not pass your basic param validation.