如何在Rails中使用帶有嵌套資源的will_paginate？

Question

我是Rails的新手，我在使用set_paginate處理嵌套資源方面遇到了很大的麻煩。

我有兩個模型，聲明和發票。 will_paginate正在處理Statement，但我無法讓它在Invoice上工作。 我知道我會做一些愚蠢的事情，但我無法弄明白，我在谷歌上找到的例子對我不起作用。

statement.rb
class Statement < ActiveRecord::Base
  has_many :invoices

  def self.search(search, page)
    paginate :per_page => 19, :page => page,
      :conditions => ['company like ?', "%#{search}%"],
      :order => 'date_due DESC, company, supplier'
  end
end

statements_controller.rb  <irrelevant code clipped for readability>
def index #taken from the RAILSCAST 51, will_paginate podcast
  @statements = Statement.search(params[:search], params[:page])
end

I call this in the view like so, and it works:
  <%= will_paginate @statements %>

但我無法弄清楚如何讓它適用於發票：

invoice.rb
class Invoice < ActiveRecord::Base
  belongs_to :statement

   def self.search(search, page)
     paginate :per_page => 19, :page => page,
       :conditions => ['company like ?', "%#{search}%"],
       :order => 'employee'
  end
end

invoices_controller.rb
class InvoicesController < ApplicationController

  before_filter :find_statement


  #TODO I can't get will_paginate to work w a nested resource
  def index #taken from the RAILSCAST 51, will_paginate podcast
        @invoices = Invoice.search(params[:search], params[:page])
  end

 def find_statement
    @statement_id = params[:statement_id]
    return(redirect_to(statements_url)) unless @statement_id
    @statement = Statement.find(@statement_id)
  end
end

我試着這樣稱呼：<％= will_paginate（@invoices）％>

我玩這個時最常見的錯誤信息是：“@ state變量似乎是空的。你忘了傳遞will_paginate的集合對象嗎？”

我不知道問題是什么，或者如何解決它。 感謝您的幫助和指導！

Answer 1

解決了 -

我將發票分頁移動到Statement的控制器中，如下所示：

def show
  @statement = Statement.find(params[:id])

  #TODO move the :per_page stuff out to a constant
  @invoices = @statement.invoices.paginate :per_page => 10,
    :page => params[:page],
    :order => 'created_at DESC'


 respond_to do |format|
    format.html # show.html.erb
    format.xml  { render :xml => @statement }
 end
end

並在這樣的視圖中調用它（為了可讀性而修剪代碼>

  <div id="pagination">
  <%= will_paginate @invoices %>
  </div>
  <table>
  <%# @statement.invoices.each do |invoice| -
  shows all invoices with no pagination,
  use @invoices instead%>
  <%
  @invoices.each do |invoice|
  %>