ruby-on-rails - 向 FormBuilder 添加一个方法，该方法调用一个渲染部分的辅助方法

Question

所以我有这个辅助方法，对吧？

def table_form_field(name_or_options = nil, *args, &block)
  # ...
  render :partial => "snippets/table_form_field", :locals => options
end

很好，除了有时我想将它与表单生成器一起使用，
为此，我必须这样称呼它:

table_form_field(:foo, :form_builder => f) do |name|
  f.text_field name
end

必须手动指定 :form_builder 很烦人。所以我的目标是扩展 ActionView::Helpers::FormBuilder并为其添加一个新方法，如下所示:

class ActionView::Helpers::FormBuilder
  def table_form_field(name_or_options, options, &block)
    if name_or_options.is_a?(Hash)
      name_or_options[:form_builder] = self
    else
      options[:form_builder] = self
    end

    # But... how can I call the helper?
    # Hmm, I'll try this:

    klass = Class.new do
      include ApplicationHelper
    end

    klass.new.send(:table_form_field, name_or_options, options, &block)

    # Thank you, Mario, but your princess is in another castle!
    #
    # Basically, this tries to call render, and for obvious
    # reasons, klass doesn't know how to render.
    #
    # So... what do I do?
  end
end

Answer 1

您可以访问一个名为 @template 的实例变量。在表单生成器中，您只需调用 table_form_field在 @template多变的。

例如，我将创建一个继承自 ActionView::Helpers::FormBuilder 的自定义表单构建器

class MyFormBuilder < ActionView::Helpers::FormBuilder
  def table_form_field(*attrs, &block)
    @template.table_form_field(*attrs, &block)
  end
end

然后在您的 form_for 中，您可以告诉它使用您的自定义表单构建器

<%= form_for @myobject, :builder => MyFormBuilder do |f| %>
  <%= f.table_form_field :myfield do %>
  <% end %>
<%= end %>