javascript - ROR - coffeescript 导致 "Uncaught ReferenceError"

Question

我得到的错误令人费解，因为我从一个 Controller / View /javascript 复制了一些工作代码进行名称更改并取出行以获得初始工作版本。导致运行时错误的 coffeescript 文件的相关部分如下。

应用程序/ Assets /javascripts/companies.js.coffee

...
calculateResult = (company_id)-> 
  data = $('#x_company_drill_interests').serialize()
  console.log(" -01- in calculateResult ")
  console.log data
  $.ajax
    url:"/companies/#{company_id}/projection.json",
    type:"post"
    dataType: 'json'   # data type of response
    data: data
    failure: (data,success,xhr)->
       console.log(" -01- in calculateResult - Failure ")
       console.log data
    success: (data,success,xhr)->
       console.log("-01- in calculateResult - SUCCESS ")
       company_listings_block = $ '#x_company_listings_results .infogroup-body'
       head_row = $ '''
<tr>
  <th>Company</th>
</tr>
'''
      table = $ '<table border="0" cellpadding="0" cellspacing="5"></table>'
      table
        .addClass('info')
        .append(head_row)
      for result in data
        name = result.display_name
        result_row = $ """
<tr>
  <td>#{name}</td>
</tr>
"""
        table.append result_row
      eval_result_block.html('').append table

产生错误:

uncaught ReferenceError: head_row is not defined

这是由 .append(head_row) 行引起的。如果删除此行，我会收到此错误 Uncaught ReferenceError: eval_result_block is not defined。

同样出于某种原因，我无法获得使用 Post 路由的代码。这是我添加修改路由文件的方式。

配置/rutes.rb

resources :companies, only: [:destroy, :update] do
  member do
    get 'companies_drill_interests'
    match 'projection', via: [:get,:post, :patch]
  end
end

引用这里是我复制的工作代码

calculateResult = (drill_id)->
  console.log("  -001- in calculate results")
  data = $('#x_evaluation_assumption_params').serialize()
  $.ajax
    url:"/drills/#{drill_id}/projection.json",
    type:"post"
    dataType: 'json'   # data type of response
    data: data
    failure: (data,success,xhr)->
      console.log("     -001- in Calculate Result - Failure ")
      console.log data
    success: (data,success,xhr)->
      # console.log("     -001-     print data from call")
      eval_result_block = $ '#x_id_evaluation_results .infogroup-body'
      head_row = $ '''
<tr>
  <th>Company</th>
  <th>Price</th>
  <th>Mkt Cap</th>
  <th>Discovery Value</th>
  <th>Target Price</th>
  <th>Leverage</th>
  <th>Risked Lev </th>
  <th>Leverage with CFD's</th>
</tr>
'''
      table = $ '<table border="0" cellpadding="0" cellspacing="5"></table>'
      table
        .addClass('info')
        .append(head_row)
      for result in data
        if !(result.listing.option_unlisted) 
          name = result.display_name
          share_price = '$' +
            NumberHelpers.number_with_precision((result.listing.share_price/1000), {separator: '.', precision: 3, delimiter: ','})
          market_capitalisation_mill = '$' +                 
             NumberHelpers.number_with_precision((result.market_capitalisation/1000000), {separator: '.', precision: 1, delimiter: ','}) + 'M'
          discovery_value = '$' + 
            NumberHelpers.number_with_precision(result.discovery_value_total, {separator: '.', precision: 0, delimiter: ','})
          discovery_value_per_share = '$' + 
            NumberHelpers.number_with_precision((result.target_share_price), {separator: '.', precision: 2, delimiter: ','})
          leverage = 
        NumberHelpers.number_with_precision(result.leverage, {separator: '.', precision: 0, delimiter: ','}) + '%'
      risked_leverage =  
            NumberHelpers.number_with_precision(result.risked_leverage, {separator: '.', precision: 0, delimiter: ','}) + '%'
          leverage_with_CFD = 
            NumberHelpers.number_with_precision(result.leverage_with_CFD, {separator: '.', precision: 0, delimiter: ','}) + '%'
          result_row = $ """
<tr>
  <td>#{name}</td>
  <td>#{share_price}</td>
  <td>#{market_capitalisation_mill}</td>
  <td>#{discovery_value}</td>
  <td>#{discovery_value_per_share}</td>
  <td>#{leverage}</td>
  <td>#{risked_leverage}</td>
  <td>#{leverage_with_CFD}</td>
</tr>
"""
        table.append result_row
      eval_result_block.html('').append table

Answer 1

在第一个代码中，eval_result_block在使用之前没有定义。关于result_row , 在它的代码的第一部分是一个 for循环，而在代码的另一部分中，它位于此 for 之外因为 risked_leverage 循环有不同的缩进，短了 4 个空格。这意味着它在 for 之外循环，所以，这就是为什么 result_row也在外面。

在 coffeescript 中，缩进很重要。如果你输入 3 个空格而不是 2 个，生成的代码将会不同。查看您的代码:

failure: (data,success,xhr)->
   console.log(" -01- in calculateResult - Failure ")
   console.log data
success: (data,success,xhr)->
   console.log("-01- in calculateResult - SUCCESS ")
   company_listings_block = $ '#x_company_listings_results .infogroup-body'
   head_row = $ '''

如果不同

failure: (data,success,xhr)->
  console.log(" -01- in calculateResult - Failure ")
  console.log data
success: (data,success,xhr)->
  console.log("-01- in calculateResult - SUCCESS ")
  company_listings_block = $ '#x_company_listings_results .infogroup-body'
  head_row = $ '''

因为在第一种情况下有 3 个空格，而在第二种情况下有 2 个空格。

此处您的代码具有正确的缩进。通过阅读你的代码，我认为 result_row和 table.append result_row必须在 for 中循环。

calculateResult = (company_id)-> 
  data = $('#x_company_drill_interests').serialize()
  console.log(" -01- in calculateResult ")
  console.log data
  $.ajax
    url:"/companies/#{company_id}/projection.json",
    type:"post"
    dataType: 'json'   # data type of response
    data: data
    failure: (data,success,xhr)->
      console.log(" -01- in calculateResult - Failure ")
      console.log data
    success: (data,success,xhr)->
      console.log("-01- in calculateResult - SUCCESS ")
      company_listings_block = $ '#x_company_listings_results .infogroup-body'
      head_row = $ '''
<tr>
  <th>Company</th>
</tr>
'''
      table = $ '<table border="0" cellpadding="0" cellspacing="5"></table>'
      table
        .addClass('info')
        .append(head_row)
      for result in data
        name = result.display_name
        result_row = $ """
<tr>
  <td>#{name}</td>
</tr>
"""
        table.append result_row
      company_listings_block.html('').append table

您可以尝试将每一部分代码编译成javascript，这将有助于您理解发生了什么。 Coffee compiler