带分组的formtastic select

现在有了formtastic,我有了简单的选择:

= f.input :category, :as => :select, :include_blank => false, :collection => subcategories

这里我只显示儿童类别。我使用 Acsthasast-树 父子关系插件。我也要显示父类别。

formtastic生成的select应该如下所示:

<select name="favoritefood">
  <optgroup label="Dairy products">
    <option>Cheese</option>
    <option>Egg</option>
  </optgroup>
  <optgroup label="Vegetables">
    <option>Cabbage</option>
    <option>Lettuce</option>
    <option>Beans</option>
    <option>Onions</option>
  <option>Courgettes</option>
  </optgroup>
  ⋮
</select>

在formtastic select中,如何使用分组作为具有树功能的模型?有人知道吗?

更新的

我发现这应该有效:

= f.input :category, :include_blank => false, :group_by => :parent

但不是错误的:

undefined local variable or method `object_class' for #<Formtastic::SemanticFormBuilder:0x87d3158>

看来formtastic里有一些虫子。我已经浏览了formtastic.rb并在 检测组关联 方法:

  def detect_group_association(method, group_by)
    object_to_method_reflection = self.reflection_for(method)
    method_class = object_to_method_reflection.klass

    method_to_group_association = method_class.reflect_on_association(group_by)
    group_class = method_to_group_association.klass

    # This will return in the normal case
    return method.to_s.pluralize.to_sym if group_class.reflect_on_association(method.to_s.pluralize)

    # This is for belongs_to associations named differently than their class
    # form.input :parent, :group_by => :customer
    # eg. 
    # class Project
    #   belongs_to :parent, :class_name => 'Project', :foreign_key => 'parent_id'
    #   belongs_to :customer
    # end
    # class Customer
    #   has_many :projects
    # end
    group_method = method_class.to_s.underscore.pluralize.to_sym
    return group_method if group_class.reflect_on_association(group_method) # :projects

    # This is for has_many associations named differently than their class
    # eg. 
    # class Project
    #   belongs_to :parent, :class_name => 'Project', :foreign_key => 'parent_id'
    #   belongs_to :customer
    # end
    # class Customer
    #   has_many :tasks, :class_name => 'Project', :foreign_key => 'customer_id'
    # end
    possible_associations =  group_class.reflect_on_all_associations(:has_many).find_all{|assoc| assoc.klass == object_class}
    return possible_associations.first.name.to_sym if possible_associations.count == 1

    raise "Cannot infer group association for #{method} grouped by #{group_by}, there were #{possible_associations.empty? ? 'no' : possible_associations.size} possible associations. Please specify using :group_association"

  end

的确 对象类 此方法中未定义,并且formtastic.rb中没有该名称的privat方法。但是我们可以用 :组关联 明确定义关联。

- semantic_form_for ([:manager, @purchase_profile]) do |f|
  - f.inputs do
    = f.input :category, :include_blank => false, :group_by => :parent, :group_association => :children
  = f.buttons

但我遇到了另一个错误:

undefined method `children' for nil:NilClass

我试着戒掉 Acsthasast-树 写下我自己的参考资料。与“作为树工作”相同,应如下所示:

class Category < ActiveRecord::Base
  belongs_to :parent, :class_name => "Category", :foreign_key => "parent_id"
  has_many :children, :class_name => "Category", :foreign_key => "parent_id"
end

错误是相同的。有人能帮忙吗?

更新的

下一步。没有formtastic的代码可以正常工作:

= grouped_collection_select('', :category_id, top_categories, :children, :name, :id, :name, :include_blank => true)

P.S:Top_Categories是父类别集合的helper方法。

最后一件事是把它翻译成formtastic语法:)