与has_many的Simple_Form关联:通过额外字段

Question

我有两个模型,开发人员和任务,

class Developer < ActiveRecord::Base
  attr_accessible :address, :comment, :email, :name, :nit, :phone, :web
  has_many :assignments
  has_many :tasks, :through => :assignments
end

class Task < ActiveRecord::Base
  attr_accessible :description, :name, :sprint_id, :developer_ids
  has_many :assignments
  has_many :developers, :through => :assignments
end

class Assignment < ActiveRecord::Base
  attr_accessible :accomplished_time, :developer_id, :estimated_time, :status, :task_id
  belongs_to :task
  belongs_to :developer
end

我通过添加一个Assignment表来处理关系,所以我可以将许多开发人员添加到一个任务中,现在我也希望能够操作我添加到连接表中的其他字段,如'estimated_time',' completed_time'...等......我在Simple_form上得到的是`

<%= simple_form_for [@sprint,@task], :html => { :class => 'form-horizontal' } do |f| %>
  <%= f.input :name %>
  <%= f.input :description %>
  <%= f.association :developers, :as => :check_boxes %>

  <div class="form-actions">
    <%= f.button :submit, :class => 'btn-primary' %>
    <%= link_to t('.cancel', :default => t("helpers.links.cancel")),
                project_sprint_path(@sprint.project_id,@sprint), :class => 'btn' %>
  </div>
<% end %>`

这只允许我选择开发人员,我希望能够在那里修改estimated_time字段.

有什么建议？

Answer 1

我喜欢简单形式的协会助手,在某些情况下让它变得非常简单.不幸的是,你想要的只是简单的形式无法解决.

你必须创建assignments这个才能工作.

有两种可能的方法.

对于两者,您必须将以下内容添加到模型中:

class Task
  accepts_nested_attributes_for :assignments
end

请注意,如果您正在使用attr_accesible,则还应添加assignments_attributes它.

简单的方法

假设您知道最多可以分配多少个分配task.假设为简单起见1.

在你的控制器中,写

def new
  @task = Task.build
  @task.assignments.build
end

这将确保有一个新的任务.

在你的视图中写道:

= simple_form_for [@sprint,@task], :html => { :class => 'form-horizontal' } do |f| 
  = f.input :name 
  = f.input :description 

  = f.simple_fields_for :assignments do |assignment|
    = assignment.association :developer, :as => :select
    = assignment.estimated_time

  .form-actions
    = f.button :submit, :class => 'btn-primary'
    = link_to t('.cancel', :default => t("helpers.links.cancel")),
                project_sprint_path(@sprint.project_id,@sprint), :class => 'btn'

这种方法的问题是:如果你想要超过1,2或3怎么办？

使用茧

Cocoon是一个允许您创建动态嵌套表单的gem.

您的观点将变为:

= simple_form_for [@sprint,@task], :html => { :class => 'form-horizontal' } do |f| 
  = f.input :name 
  = f.input :description 

  = f.simple_fields_for :assignments do |assignment|
    = render `assignment_fields`, :f => assignment
  .links
    = link_to_add_association 'add assignment', f, :assignments

  .form-actions
    = f.button :submit, :class => 'btn-primary'
    = link_to t('.cancel', :default => t("helpers.links.cancel")),
                project_sprint_path(@sprint.project_id,@sprint), :class => 'btn'

并定义一个部分_assignment_fields.html.haml:

.nested_fields
  = f.association :developer, :as => :select
  = f.estimated_time
  = link_to_remove_association 'remove assignment', f

希望这可以帮助.