在 Rails 上从头开始创建 PDF

Question

我正在为我的简单应用程序创建一个 pdf 收据。我能够使其适用于通用/主要是硬编码的条目。但是，当我希望 pdf 打印出特定费用的金额（非硬编码）时，我在 charge_controller.rb 文件中收到此错误 - “未定义的局部变量或方法 'amount' for #”我在下面列出我的特定 github 以及下面的相关内容。非常感谢你们的帮助:)

确切的错误信息：

未初始化的常量 Charge::Amount app/models/charge.rb:18:in receipt' app/controllers/charges_controller.rb:64:inblock (2 个级别) in show' app/controllers/charges_controller.rb:60:in `show'

Github - https://github.com/OmarZV/PDF

charges_controller.rb

class ChargesController < ApplicationController
before_action :authenticate_user!
before_action :set_charge, only: [:show]
def index
@charges = Charge.all
end
def new
@charge = Charge.new
end
def create
@charge = Charge.new(charge_params)
respond_to do |format|
if @charge.save
format.html { redirect_to @charge, notice: 'Charge was successfully created.' }
    format.json { render :show, status: :created, location: @charge }
  else
    format.html { render :new }
    format.json { render json: @charge.errors, status: :unprocessable_entity }
  end
end
end
def show
respond_to do |format|
    format.html
    format.json
    format.pdf {
    send_data @charge.receipt.render,
      filename: "#{@charge.created_at.strftime("%Y-%m-%d")}-gorails-receipt.pdf",
      type: "application/pdf",
      disposition: :inline
  }
end
end
private
def set_charge
@charge = current_user.charges.find(params[:id])
end
end

charge.rb 工作时

class Charge < ApplicationRecord
belongs_to :user
def receipt
Receipts::Receipt.new(
id: id,
  product: "GoRails",
  company: {
    name: "One Month, Inc.",
    address: "37 Great Jones\nFloor 2\nNew York City, NY 10012",
    email: "teachers@onemonth.com",

  },
  line_items: [
    ["Date",           created_at.to_s],
    ["Account Billed", "(#{user.email})"],
    ["Product",        "GoRails"],
    ["Amount",         "Amount"],
    ["Charged to",     "{Card_type}"],

  ]      
)
end
end

charge.rb 不起作用时

class Charge < ApplicationRecord
belongs_to :user
def receipt
Receipts::Receipt.new(
id: id,
  product: "GoRails",
  company: {
    name: "One Month, Inc.",
    address: "37 Great Jones\nFloor 2\nNew York City, NY 10012",
    email: "teachers@onemonth.com",

  },
  line_items: [
    ["Date",           created_at.to_s],
    ["Account Billed", "(#{user.email})"],
    ["Product",        "GoRails"],
    ["Amount",         "$#{Amount / 100}.00"],
    ["Charged to",     "#{Card_type} (**** **** **** #{Card_last4})"],

  ]      
)
end
end

user.rb

class User < ApplicationRecord
devise :database_authenticatable, :registerable,:recoverable, :rememberable, :trackable, :validatable
has_many :charges
end

Answer 1

您的模型中有一个大写字母Amount，它将引用一个常量。应该是小写的amount，才能使用费用记录上的属性。

我认为应该是：["Amount", "$#{amount / 100}.00"]