Rails 将视图设置为在 before_filter 中渲染

Question

是否可以设置从 before_filter 渲染的视图？

class ProductsController < ApplicationController
  before_filter :set_special_view


  def action1
    # some logic

    # i do not want to call render here
  end

  def action2
    # some logic

    # i do not want to call render here
  end

  private

  def set_special_view
    #self.class.view 'products/v1.html.erb' if some_cond?
    #self.class.view 'products/v2.html.erb' if anoter_cond?


    #self.class.layout :somelayout if some_cond?

  end
end

布局可以做为

self.class.layout :somelayout if some_cond?

有设置视图的方法吗？所以我在 before_filter 中设置了视图，我不触摸动作。

Answer 1

可以通过在我的控制器中覆盖 default_render 来完成：

class ProductsController < ApplicationController

before_filter :set_special_view


  def action1
    # some logic

  end

  def action2
    # some logic

  end

  def default_render(*args)
    unless @myview.nil?
      render @myview and return
    end

    super
  end


  private

  def set_special_view
    # decide which view to show here

    @myview = 'products/v1.html.erb' if cond1?
    @myview = 'products/v2.html.erb' if cond2?

  end
end

default_render 放在 'actionpack/lib/action_controller/metal/implicit_renderer.rb' 中只调用 render 而不带参数：

module ActionController
  module ImplicitRender
    def send_action(method, *args)
      ret = super
      default_render unless performed?
      ret
    end

    def default_render(*args)
      render(*args)
    end

    def method_for_action(action_name)
      super || if template_exists?(action_name.to_s, _prefixes)
        "default_render"
      end
    end
  end
end

在我们的 default_render 中，我们使用视图模板调用 render。

在此处查看 Rails 如何呈现模板 - http://climber2002.github.io/blog/2015/02/21/how-rails-finds-your-templates-part-1/

Answer 2

使用and return 在渲染后不运行任何逻辑。

def set_special_layout
  #render 'products/v1' and return if some_cond?
  #render 'products/v2' and return if anoter_cond?

  #self.class.layout :somelayout if some_cond?

end