我今天遇到這個錯誤,我搜索谷歌的解決方案,但我找不到這個正確的答案。錯誤:未定義的方法ID爲零:NilClass(NoMethodError)
NoMethodError at /master/hotels/import
undefined method `id' for nil:NilClass
這是templete文件:
row
.col-xs-12
%p.pull-left
%button.btn.btn-white.btn-sm
一括削除
%p.pull-right
= link_to "新規作成", url_for(action: :new), class: "btn btn-white btn-sm"
= link_to "CSV Export", url_for(action: :index, format: 'csv'), class: "btn btn-white btn-sm"
= link_to "CSV Upload", url_for(action: :import), class: "btn btn-white btn-sm"
-#= form_tag url_for(action: :import), class: 'pull-right' do |f|
-#= file_field_tag :csv, as: :file
-#= submit_tag "CSV Upload", input_html: {class: "btn btn-white btn-sm"}
.col-xs-12
= render 'cruds/grid'
,這裏是我的控制器文件:
class CrudsController < ApplicationController
before_action :load_crud
before_action :set_crud, only: [:show, :edit, :update, :destroy]
def load_crud
end
# GET /cruds
# GET /cruds.json
def index
@items_grid = initialize_grid(@model)
@csv = CSV.generate() do |csv|
csv << @model.column_names
@model.all.each do |item|
csv << item.attributes.values_at(*@model.column_names).map{|i| i.to_s.encode("cp932", "UTF-8")}
end
end
respond_to do |format|
format.html { render template: 'cruds/index'}
format.csv { send_data @csv }
#format.xls # {send_data @product.to_csv (col_sep: "|t")}
end
# render template: 'cruds/index'
end
# GET /cruds/1
# GET /cruds/1.json
def show
render template: 'cruds/show'
end
# GET /cruds/new
def new
@crud = @model.new
render template: 'cruds/new'
end
# GET /cruds/1/edit
def edit
render template: 'cruds/edit'
end
# POST /cruds
# POST /cruds.json
def create
@crud = @model.new(crud_params)
respond_to do |format|
if @crud.save
format.html { redirect_to [:master, @crud], notice: 'Crud was successfully created.' }
format.json { render action: 'show', status: :created, location: @crud }
else
format.html { render action: 'new' }
format.json { render json: @crud.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /cruds/1
# PATCH/PUT /cruds/1.json
def update
respond_to do |format|
if @crud.update(crud_params)
format.html { redirect_to [:master, @crud], notice: 'Crud was successfully updated.' }
format.json { head :no_content }
else
format.html { render action: 'edit' }
format.json { render json: @crud.errors, status: :unprocessable_entity }
end
end
end
# DELETE /cruds/1
# DELETE /cruds/1.json
def destroy
@crud.destroy
respond_to do |format|
format.html { redirect_to action: :index }
format.json { head :no_content }
end
end
def import
@model.import(params[:file])
redirect_to root_url, notice: "Products imported."
end
private
# Use callbacks to share common setup or constraints between actions.
def set_crud
@crud = @model.find_by_id(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def crud_params
params[@hash].permit(@model.attribute_names)
end
末
我對這個錯誤很迷茫,有人可以告訴我任何解決方案嗎?
如果您將堆棧跟蹤與錯誤一起粘貼,那就太好了。原因是,某處某處調用了'nil'上的'id'方法。 – Amadan
屏幕截圖錯誤在這裏:http://postimg.org/image/b2mwn3usp/希望它有幫助 – dailammoc
Stack Overover之外的屏幕截圖被忽視,因爲它們可能會過期並破壞問題。此外,處理文本比圖像更容易。最後,它沒有堆棧跟蹤(儘管它確實有錯誤發生的代碼,所以很幸運)。 – Amadan