Rails, MongoMapper nested Array in HAML form troub

问题:

I'm getting

undefined method `Carrots' for # (referencing ln#18)

When trying to edit with the below form:

= 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'

Using the data below:

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

I've tried related Stack Overflow questions for MongoMapper, Rails and Embedded documents but I am not having any luck, perhaps due to this being a nested Array rather than EmbeddedDocument. I'm not using Formtastic or anything yet, would just like to understand the syntax required here first.

回答1:

This is definitely not efficient, but this allowed me to get the job done:

= 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'