Question

我正在尝试从像这样的rake任务中访问名为Book的模型

task :create_epubs => :environment do
  include Rails.application.routes.url_helpers # brings ActionDispatch::Routing::UrlFor
  include ActionView::Helpers::TagHelper

  av = ActionView::Base.new(Rails.root.join('app', 'views'))

  books = Book.all
  av.render("books/", :books => books)
end

但我收到以下警告

rake aborted!
undefined method `to_sym' for nil:NilClass

Tasks: TOP => create_epubs
(See full trace by running task with --trace)

我正在尝试像下面的accessing rails models from rake task那样加载环境但是对于rails 3.1来说可能稍微偏离了

*编辑Book.all会在我放入Book.all.to_yaml时返回一些内容，因此to_sym错误可能是av.render中的其他内容

我已经弄明白了问题所在。我在我看来是指实例变量。

有人能告诉我如何通过设置该变量继续使用实例变量吗？

当我将实例变量更改为：params变量

时，这是工作版本

task :create_epubs => [:environment] do
  av = ActionView::Base.new(Rails.root.join('app', 'views'), :assigns => self)
  av.view_paths = ActionController::Base.view_paths
  av.extend ApplicationHelper #or any other helpers your template may need

  book = Book.first

  puts av.render(:template => "books/epub-show", :locals => {:book => book}, :layout => false) # this isn't passing @book to the view correctly, i get undefined method for nil:nilClass
end

Answer 1

你应该使用实例变量。

@book = Book.first

并在你的渲染中

:locals => { :book => @book }

另外，我想你想要

:layout => nil

Rake任务访问模型

1 个答案: