Rails 4 CollectionProxy错误

Question

我在一个名为bill的模型的表单上有一个集合，该模型显示带有文本框的集合 #<Sponsorship::ActiveRecord_Associations_CollectionProxy:0x007f99a874bcd0> 而不是下拉列表。有什么想法吗？

bill.rb

class Bill < ActiveRecord::Base
        belongs_to :congress_person
        has_many :bps, :dependent => :destroy
        has_many :committees, :dependent => :destroy
        has_many :sponsorships, -> { where(kind: :primary) }, class_name: "Sponsorship" 
        has_many :cosponsorships, -> { where(kind: :secondary) }, class_name: "Sponsorship"

        has_many :sponsors, class_name: 'CongressPerson', through: :sponsorships
        has_many :cosponsors, class_name: 'CongressPerson', through: :cosponsorships

congress_people.rb

has_many :sponsorships, -> { where(kind: :primary) }, class_name: "Sponsorship", foreign_key: :sponsor_id
    has_many :cosponsorships, -> { where(kind: :secondary) }, class_name: "Sponsorship", foreign_key: :sponsor_id

    has_many :sponsored_bills, through: :sponsorships, source: :bill
    has_many :cosponsored_bills, through: :cosponsorships, source: :bill

sponsorship.rb

belongs_to :bill
belongs_to :sponsor, class_name: "CongressPerson"
belongs_to :cosponsor, class_name: "CongressPerson"

_form.html.haml

...
.row-fluid
                .col-md-12
                    %h3 Sponsor
                    #sponsors-form
                        = f.simple_fields_for :sponsors do |sponsor|
                            = render 'sponsor_fields', f: sponsor
                        .links
                        = link_to_add_association 'Add Sponsor', f, :sponsors, class: 'btn btn-secondary add-button'
...

_sponsors_fields.html.haml

.form-inline.clearfix
    .row
        .nested-fields
            = f.input :sponsorships, :collection => @congress_people

            = link_to_remove_association "Remove", f, class: "form-control btn btn-secondary", style: 'height:20%; display:inline; float:right;' 

Answer 1

如果接受multiple：true，则可能会发生这种情况。 否则，这应该足够了：

= f.input :sponsorships, :collection => @congress_people

此外，@congress_people需要在您的控制器方法中可用。