Rails ActiveResource关联

Question

我有一些ARes模型(见下文),我正在尝试使用关联(这似乎完全没有文档,也许不可能,但我想我会尝试一下)

所以在我的服务方面,我的ActiveRecord对象将呈现类似的东西

render :xml => @group.to_xml(:include => :customers)

(参见下面生成的xml)

模型组和客户是HABTM

在我的ARes方面,我希望它可以看到<customers>xml属性并自动填充该.customersGroup对象的属性,但是不支持has_many等方法(至少据我所知)

所以我想知道ARes如何反映XML来设置对象的属性.例如,在AR中,我可以def customers=(customer_array)自己创建并设置它,但这似乎在ARes中不起作用.

我找到一个"关联"的建议就是有一个方法

def customers
  Customer.find(:all, :conditions => {:group_id => self.id})
end

但这有一个缺点,就是它会进行第二次服务电话来查找这些客户......并不酷

我希望我的ActiveResource模型能够看到XML中的客户属性并自动填充我的模型.有人对此有经验吗？？

# My Services
class Customer < ActiveRecord::Base
  has_and_belongs_to_many :groups
end

class Group < ActiveRecord::Base
  has_and_belongs_to_many :customer
end

# My ActiveResource accessors
class Customer < ActiveResource::Base; end
class Group < ActiveResource::Base; end

# XML from /groups/:id?customers=true

<group>
  <domain>some.domain.com</domain>
  <id type="integer">266</id>
  <name>Some Name</name>
  <customers type="array">
    <customer>
      <active type="boolean">true</active>
      <id type="integer">1</id>
      <name>Some Name</name>
    </customer>
    <customer>
      <active type="boolean" nil="true"></active>
      <id type="integer">306</id>
      <name>Some Other Name</name>
    </customer>
  </customers>
</group>

Answer 1

ActiveResource不支持关联.但它并不能阻止您在ActiveResource对象中设置/获取复杂数据.以下是我将如何实现它:

服务器端模型

class Customer < ActiveRecord::Base
  has_and_belongs_to_many :groups
  accepts_nested_attributes_for :groups
end

class Group < ActiveRecord::Base
  has_and_belongs_to_many :customers
  accepts_nested_attributes_for :customers
end

服务器端GroupsController

def show
  @group = Group.find(params[:id])
  respond_to do |format|
    format.xml { render :xml => @group.to_xml(:include => :customers) }
  end    
end

客户端模型

class Customer < ActiveResource::Base
end

class Group < ActiveResource::Base
end

客户端GroupsController

def edit
  @group = Group.find(params[:id])
end

def update
  @group = Group.find(params[:id])
  if @group.load(params[:group]).save
  else
  end
end

客户端视图:从Group对象访问客户

# access customers using attributes method. 
@group.customers.each do |customer|
  # access customer fields.
end

客户端:将客户设置为组对象

group.attributes['customers'] ||= [] # Initialize customer array.
group.customers << Customer.build