Rails, MongoMapper 嵌套数组在 HAML 表单中的麻烦答案

【问题标题】：Rails, MongoMapper nested Array in HAML form troubleRails, MongoMapper 嵌套数组在 HAML 表单中的麻烦
【发布时间】：2012-09-30 06:02:20
【问题描述】：

我明白了

# 的未定义方法 `Carrots'（引用 ln#18）

尝试使用以下表单进行编辑时：

= form_for @harvest do |f|
  - if @harvest.errors.any?
    #error_explanation
      %h2= "#{pluralize(@harvest.errors.count, "error")} prohibited this harvest from being saved:"
      %ul
        - @harvest.errors.full_messages.each do |msg|
          %li= msg

  .field
    = f.label :created_at
    = f.text_field :created_at, :disabled => true
    %br
    = f.label :photo
    = f.text_field :photo
    %h2 Crops
    - @harvest.harvested_crops.each do |harvested_crop|
      = f.label :harvested_crop['crop']
      = f.select harvested_crop['crop'], Crop.all.collect {|p| [ p.name, p.id ] }, {:include_blank => ''}
      = f.label :harvested_crop['amount']
      = f.text_field harvested_crop['amount']

  %br
  .actions
    = f.submit 'Save'

使用以下数据：

{ "_id" : ObjectId("5067846f37bca62bccc3729e"), "user_id" : "5067844637bca62bccc3729c", "photo" : "carrotsnspuds.jpg", "harvested_crops" : [    {   "crop" : "Carrots",     "amount" : 1112.15 },   {   "crop" : "Potatoes",    "amount" : 3212.44 } ] }

我已经为 MongoMapper、Rails 和 Embedded 文档尝试了相关的 Stack Overflow 问题，但我没有任何运气，可能是因为这是一个嵌套数组而不是 EmbeddedDocument。我还没有使用 Formtastic 或任何东西，只是想先了解这里所需的语法。

【问题讨论】：

标签： ruby-on-rails forms mongodb haml

【解决方案1】：

这绝对没有效率，但这让我能够完成工作：

= form_for @harvest do |f|
  - if @harvest.errors.any?
    #error_explanation
      %h2= "#{pluralize(@harvest.errors.count, "error")} prohibited this harvest from being saved:"
      %ul
        - @harvest.errors.full_messages.each do |msg|
          %li= msg

  .field
    = f.label :created_at
    = f.text_field :created_at, :disabled => true
    %br
    = f.label :photo
    = f.text_field :photo
    %h2 Crops
    - x = 0
    - @harvest.harvested_crops.each do |harvested_crop|
      = f.fields_for "harvested_crops[]", harvested_crop do |hc|
        %b Harvested Crop
        %select{:name => "harvest[harvested_crops][" + x.to_s + "][crop]"}
          - Crop.all.collect.each do |crop_name|
            - if harvested_crop['crop'] == crop_name[:name]
              %option{:selected => "selected", :value => crop_name[:name]}
                = crop_name[:name]
            - else
              %option{:value => crop_name[:name]}
                = crop_name[:name]
        %b Amount
        %input{:name => "harvest[harvested_crops][" + x.to_s + "][amount]", :value => harvested_crop['amount']}/
        %br
        - x += 1

  %br
  .actions
    = f.submit 'Save'

【讨论】：