这应该是非常简单且有据可查的,我已经这样做了好几次了,尽管有些事情仍然让我很烦恼。
我有一个调用嵌套部分的部分结构。
在某个时刻一render
调用需要将额外的变量传递给部分,尽管部分的渲染失败并显示:
undefined local variable or method `<variable name>' for #<#<Class:....>
这是我的调用代码render
:
= f.simple_fields_for :orders do |c|
= render partial: "fields", locals: {f: c, step: f.object.step}
虽然这也不起作用:
= f.simple_fields_for :orders do |c|
= render "fields", f: c, step: f.object.step
这是引发异常的地方:
f.input :quantity, input_html: {step: step}
form_for 来自views/lists/_form.html.haml
:
= simple_form_for( @order, :html => { :multipart => true }, defaults: { input_html: { class: 'input-medium' } } ) do |f|
f
然后传递给views/orders/_order_forms.html
via
= render "orders/order_forms", f: f
这是跟踪的异常:
ActionView::Template::Error (undefined local variable or method `step' for #<#<Class:0x007fe0479ba2b0>:0x007fe04256a930>):
application trace:
app/views/orders/_fields.html.haml:9:in `_app_views_orders__fields_html_haml___1860431911739668171_70300581339300'
app/views/orders/_order_forms.html.haml:30:in `_app_views_orders__order_forms_html_haml__2241963939037094859_70300612771460'
app/views/lists/_form.html.haml:48:in `block in _app_views_lists__form_html_haml__1669043093238943449_70300583658680'
app/views/lists/_form.html.haml:3:in `_app_views_lists__form_html_haml__1669043093238943449_70300583658680'
app/views/lists/new.html.erb:3:in `_app_views_lists_new_html_erb___1563391577928218041_70300593681100'
app/controllers/lists_controller.rb:67:in `new'
框架跟踪(结束):
actionpack (3.2.8) lib/action_view/template.rb:145:in `block in render'
activesupport (3.2.8) lib/active_support/notifications.rb:125:in `instrument'
actionpack (3.2.8) lib/action_view/template.rb:143:in `render'
actionpack (3.2.8) lib/action_view/renderer/partial_renderer.rb:265:in `render_partial'
actionpack (3.2.8) lib/action_view/renderer/partial_renderer.rb:238:in `block in render'
actionpack (3.2.8) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.8) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.8) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
actionpack (3.2.8) lib/action_view/renderer/partial_renderer.rb:237:in `render'
actionpack (3.2.8) lib/action_view/renderer/renderer.rb:41:in `render_partial'
actionpack (3.2.8) lib/action_view/helpers/rendering_helper.rb:27:in `render'
haml (4.0.3) lib/haml/helpers/action_view_mods.rb:10:in `block in render_with_haml'
haml (4.0.3) lib/haml/helpers.rb:89:in `non_haml'
haml (4.0.3) lib/haml/helpers/action_view_mods.rb:10:in `render_with_haml'
cocoon (1.2.0) lib/cocoon/view_helpers.rb:40:in `block in render_association'
我以前也遇到过类似的问题,我通过简化当地人的通行来解决了这个问题。但现在我真的很想了解发生了什么。
有什么线索吗?
我在用着:
ruby 2.0.0p297
rails 3.2.8
提前非常感谢..
UPDATE
我已经调试了我的视图并发现order_forms
被渲染两次,第一次step
未设置,而在第二次渲染中设置正确。
我不确定为什么会发生这种情况,但我设法通过将以下行添加到我的fields.html.haml
.
-step = step || 1
基本上,我为步骤设置了一个默认值,以防未定义,这样在第一次执行时渲染不会崩溃,而在第二次执行时它可以正常工作。
该页面现在看起来符合预期。尽管我在考虑渲染两次时会浪费资源。
知道为什么会发生这种情况吗?