ActionController :: ParameterMissing(param丢失或值为空:film):

Question

所以,当我试图访问我的应用程序上的电影页面时,我收到以下错误:

ActionController::ParameterMissing (param is missing or the value is empty: film):
2014-07-24T22:04:44.622356+00:00 app[web.1]: app/controllers/saas_admin/films_controller.rb:54:in `permitted_params'

请参阅下面的电影控制器代码

films_controller.rb

class SaasAdmin::FilmsController < SaasAdminController
  inherit_resources
  belongs_to :studio, :finder => :find_by_id!, :param => :studio_id, :class_name => Studio

  before_filter :set_sort_fields, :only => :edit
  before_filter :build_collections, :only => [:new, :create, :edit, :update]

  def create
    create! { parent_path(parent.id) } # Redirect to studio in case studio_id is changed
  end

  def update
    @film = Film.find_by_permalink(params[:id])

    respond_to do |format|
      if @film.update(permitted_params)
        format.html { redirect_to saas_admin_studio_path(@film.studio), notice: 'Film was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @film.errors, status: :unprocessable_entity }
      end
    end
  end

  def index
    redirect_to parent_path(parent.id)
  end

  def show
    @clips = resource.clips.paginate(:page => params[:page], :per_page => 30, :order => 'clips.position')
  end

  protected

  def resource
    # @film ||= end_of_association_chain.find_by_permalink!(params[:id])
    @film ||= end_of_association_chain.find_by_permalink!(params[:id])
  end

  def collection
    @films ||= end_of_association_chain.paginate(:page => params[:page], :per_page => 30, :order => 'films.created_at')
  end

  def set_sort_fields
    resource.sort_name = '' if resource.name == resource.sort_name
  end

  def build_collections
    @studios ||= Studio.find(:all)
  end

  def permitted_params
    params.require(:film).permit(:name, :sort_name, :description, :short_description, :meta_data,
        :poster, :amazon_link, :active, :trackable, :country_ids => [])
  end
end

这可能是什么？我一直试图弄清楚它,但也许一双新鲜的眼睛会发现它很简单.

干杯!

编辑

这是films/new.html.erb的视图代码

<h1><%= @page_title = "New #{resource_class}" %></h1>

<%= form_for resource, :url => collection_path, :html => { :multipart => true } do |f| -%>
  <%= render :partial => "form", :locals => { :f => f } %>
<% end -%>

<% content_for :sidebar do %>
  <%= render :partial => "saas_admin/shared/sidebar" %>
<% end %>

和电影/ edit.html.erb

<h1><%= @page_title = "Edit #{resource_class}" %></h1>

<%= form_for resource, :url => saas_admin_studio_film_path(parent, resource), :html => { :multipart => true } do |f| -%>
  <%= render :partial => "form", :locals => { :f => f } %>
<% end -%>

<% content_for :sidebar do %>
  <%= render :partial => "saas_admin/shared/sidebar" %>
<% end %>

编辑2

这里参考的是如何在工作时定义允许的参数:

 def permitted_params

{:film => params.fetch(:film, {}).permit(
:name, :sort_name, :description, :short_description, :meta_data,
:poster, :amazon_link, :active, :trackable)}

end

Answer 1

当我使用Angular JS表单将数据发送到后端Rails 4时,我也遇到了这个问题.当我没有填充角度js表单中的任何内容时,错误将显示ActionController::ParameterMissing (param is missing or the value is empty:.

我通过将params.fetch(:film, {})强参数添加到:

params.fetch(:film, {}).permit(:name, :sort_name, :description, :short_description, :meta_data,
    :poster, :amazon_link, :active, :trackable, :country_ids => [])

我引用代码示例来避免ActionController :: ParameterMissing(param丢失或值为空:film)

我希望这能帮到您.

Answer 2

发生这种情况是因为您已指定通过strong_params(在您的allowed_pa​​rams代码中指定)在参数中要求"电影".

无论视图方面正在做什么(无论是链接还是形式/等),它都没有传递嵌套在"电影"下的参数

例如.)如果你raise params.inspect在控制器动作中,你会看到没有"电影"的节点.

最有可能出现的问题是,您在视图侧的表单代码未设置为正确嵌套这些参数,form_tag例如,您使用的是吗？

Answer 3

为什么不这样使用:

def creation_params
params.permit(:film)
end

它为我工作!;)