ActionController :: ParameterMissing（參數缺失或值為空：出價）

Question

當我嘗試自定義我的bid_params以向數據庫添加參數時，出於某些原因，我的強參數無法正常工作。 我需要能夠在創建出價時將current_user傳遞到數據庫中。 該對象嵌套在與Auctions的has_many所屬關系中。 這是我的控制器：

class BidsController < ApplicationController
  def index
    @auction = Auction.find(params[:auction_id])
    @bids = @auction.bids
  end

  def new
    @auction = Auction.find(params[:auction_id])
    @bid = @auction.bids.build
  end

  def create
    @auction = Auction.find(params[:auction_id])
    @bid = @auction.bids.create(bid_params)
    if @bid.save
      flash[:success] = "Bid has been successfully placed."
      redirect_to @auction
    else
      flash[:error] = @bid.errors.full_messages.join('. ')
      render 'new'
    end
  end

  def destroy
     @auction = Auction.find(params[:auction_id])
     @bid = @auction.bids.find
    @bid.destroy
    flash[:notice] = "Successfully destroyed Bid."
    redirect_to auction_url(@bid.article_id)
  end

  private

  def bid_params
    params.require(:bid).permit(:auction_id).merge(bidder: current_user)
  end

end

和堆棧跟蹤：

Started POST "/auctions/2/bids" for 127.0.0.1 at 2014-12-06 08:54:35 -0600
Processing by BidsController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"6x4hV8y323a10kaJN5Rubj1z3uhUrSDQrD6aoaWCUhk=", "commit"=>"Create Bid", "auction_id"=>"2"}
  Auction Load (0.1ms)  SELECT  "auctions".* FROM "auctions"  WHERE "auctions"."id" = ? LIMIT 1  [["id", 2]]
Completed 400 Bad Request in 2ms

ActionController::ParameterMissing (param is missing or the value is empty: bid)

新表格：

<h1>Create a New Bid</h1>
<%= form_for ([@auction, @bid]) do |f|%>
<p>
<%= f.submit %>
</p>
<%end%>

謝謝！

Answer 1

查看控制器收到的參數：

Parameters: {"utf8"=>"✓", "authenticity_token"=>"6x4hV8y323a10kaJN5Rubj1z3uhUrSDQrD6aoaWCUhk=", "commit"=>"Create Bid", "auction_id"=>"2"}

然后，您嘗試允許這些參數：

def bid_params
  params.require(:bid).permit(:auction_id).merge(bidder: current_user)
end

在此操作中引發了錯誤： params.require(:bid)因為此方法假定您的params看起來像：

{ ..., "bid" => { "auction_id" => "2" } } 

因此，您可以更改發送參數的view / js或將def bid_params實現更改為：

def bid_params
  params.permit(:auction_id).merge(bidder: current_user)
end