Ruby on rails 从上传的文件中选择化身

我已经安装了carrierwave，用户可以上传照片。我该如何设置，以便用户不必上传化身文件，而是可以从上传的照片中选择哪一张将作为他们的化身？例如，当你在Facebook上，点击你的一张照片，点击“选项”链接，它会显示“制作个人资料图片”。然后，该图像将成为您的头像，或在整个Facebook上使用的图片。我也在找同样的东西

画廊管理员：

 def index
    @galleries = Gallery.all
  end

  def show
    @gallery = Gallery.find(id_params)
  end

  def new
    @gallery = Gallery.new
  end

  def create
    @gallery = Gallery.new(gallery_params)
    if @gallery.save
      flash[:notice] = "Created gallery."
      redirect_to @gallery
    else
      render :action => 'new'
    end
  end

  def edit
    @gallery = Gallery.find(id_params)
  end

  def update
    @gallery = Gallery.find(id_params)
    if @gallery.update_attributes(gallery_params)
      flash[:notice] = "Updated gallery."
      redirect_to gallery_url
    else
      render :action => 'edit'
    end
  end

  def destroy
    @gallery = Gallery.find(id_params)
    @gallery.destroy
    flash[:notice] = "Gallery deleted."
    redirect_to galleries_url
  end

  private


   def gallery_params
     params.require(:user).permit(:name)
   end

   def id_params
     params.require(:id).permit(:name)
   end

end

def new 
    @photo = Photo.new
  end


  def create
    @photo = Photo.new(params[:photo])
    @photo.user = current_user
    if @photo.save
      flash[:notice] = "Successfully created photos."
      redirect_to :back
    else
      render :action => 'new'
    end
  end


  def edit
    @photo = Photo.find(params[:id])
  end

  def update
    @photo = Photo.find(params[:id])
    if @photo.update_attributes(paramas[:photo])
      flash[:notice] = "Successfully updated photo."
      redirect_to @photo.gallery
    else
      render :action => 'edit'
    end
  end

  def destroy
    @photo = Photo.find(params[:id])
    @photo.destroy
    flash[:notice] = "Successfully destroyed photo."
    redirect_to @photo.gallery
  end
end

照片控制器：

 def index
    @galleries = Gallery.all
  end

  def show
    @gallery = Gallery.find(id_params)
  end

  def new
    @gallery = Gallery.new
  end

  def create
    @gallery = Gallery.new(gallery_params)
    if @gallery.save
      flash[:notice] = "Created gallery."
      redirect_to @gallery
    else
      render :action => 'new'
    end
  end

  def edit
    @gallery = Gallery.find(id_params)
  end

  def update
    @gallery = Gallery.find(id_params)
    if @gallery.update_attributes(gallery_params)
      flash[:notice] = "Updated gallery."
      redirect_to gallery_url
    else
      render :action => 'edit'
    end
  end

  def destroy
    @gallery = Gallery.find(id_params)
    @gallery.destroy
    flash[:notice] = "Gallery deleted."
    redirect_to galleries_url
  end

  private


   def gallery_params
     params.require(:user).permit(:name)
   end

   def id_params
     params.require(:id).permit(:name)
   end

end

def new 
    @photo = Photo.new
  end


  def create
    @photo = Photo.new(params[:photo])
    @photo.user = current_user
    if @photo.save
      flash[:notice] = "Successfully created photos."
      redirect_to :back
    else
      render :action => 'new'
    end
  end


  def edit
    @photo = Photo.find(params[:id])
  end

  def update
    @photo = Photo.find(params[:id])
    if @photo.update_attributes(paramas[:photo])
      flash[:notice] = "Successfully updated photo."
      redirect_to @photo.gallery
    else
      render :action => 'edit'
    end
  end

  def destroy
    @photo = Photo.find(params[:id])
    @photo.destroy
    flash[:notice] = "Successfully destroyed photo."
    redirect_to @photo.gallery
  end
end

---

下面是我可能做的一个例子

class UserAvatarController < ApplicationController
  def edit
    @gallery = current_user.gallery
    # render gallery of photos for user to choose
  end

  def update
    if params[:photo_id].present?
      current_user.update_attributes avatar_id: params[:photo_id]
    else
      flash[:error] = "No photo selected"
      render action: "edit"
    end
  end
end

---

下面是我可能做的一个例子

class UserAvatarController < ApplicationController
  def edit
    @gallery = current_user.gallery
    # render gallery of photos for user to choose
  end

  def update
    if params[:photo_id].present?
      current_user.update_attributes avatar_id: params[:photo_id]
    else
      flash[:error] = "No photo selected"
      render action: "edit"
    end
  end
end