ruby-on-rails - 如何在表单中访问上传的照片？

Question

我有一个创建项目的表格，该项目可以包含五张照片。

在我的 _form.html.erb 中，我打电话时无法访问我上传的照片，multipart => true但在我的节目中它们可以访问。如果有任何现有照片，我想在 edit.erb 和删除选项中显示现有照片。我可以访问节目中上传的照片。

这是我的 _form.html.erb：

<%= form_for @project, :html => { :multipart => true } do |f| %>
  <% if @project.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@project.errors.count, "error") %> prohibited this project from being saved:</h2>

      <ul>
      <% @project.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :title %><br>
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :description %><br>
    <%= f.text_area :description %>
  </div>

  <div class="newPaperclipFiles">

        <%= f.fields_for :assets do |asset| %>

           <% if asset.object.new_record? %>
                 <%= asset.file_field :photo %>
           <% end %>

       <% end %>

</div>

<div class="existingPaperclipFiles">

     <% f.fields_for :assets do |asset| %>

          <% unless asset.object.new_record? %>

                <div>
                        <%=image_tag asset.photo.url(:small) %>
                </div>
                        <%= asset.check_box :_destroy %>      
        <% end %>
     <% end %>
</div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

我可以访问照片的 show.erb：

    <div class="existingPaperclipFiles">

      <% @project.assets.each do |asset| %>
        <div>
        <%= image_tag asset.photo.url(:small) %>
      </div>
      <% end %>

    </div>
<p>
  <strong>Title:</strong>
  <%= @project.title %>
</p>

<p>
  <strong>Description:</strong>
  <%= @project.description %>
</p>

<%= link_to 'Edit', edit_project_path(@project) %> |
<%= link_to 'Back', projects_path %>

我的资产模型：

class Asset < ActiveRecord::Base
  require 'paperclip'

  belongs_to :project, :foreign_key => "project_id"
  attr_accessible :project_id, :photo
  has_attached_file :photo, :styles => {  :thumb => "600x600#", :medium => "300x300#", :small => "160x160#"}
end

我的项目模型：

class Project < ActiveRecord::Base
  has_permalink :title
  default_scope :order => 'created_at desc'
  attr_accessible :title, :description, :assets_attributes, :dependent => :destroy
  validates_uniqueness_of :title
  validates_presence_of :title
  has_many :assets, :dependent => :destroy
  accepts_nested_attributes_for :assets, :allow_destroy => true
end

---

编辑：

项目负责人：

class ProjectsController < ApplicationController
  before_filter :authenticate_admin!, :except => [:show]
  before_action :set_project, only: [:show, :edit, :update, :destroy]

  # GET /projects
  # GET /projects.json
  def index
    @projects = Project.all
  end

  # GET /projects/1
  # GET /projects/1.json
  def show

  end

  # GET /projects/new
  def new
    @project = Project.new()
    (5 - @project.assets.length).times { @project.assets.build }

    respond_to do |format|
      format.html # new.html.erb
      format.xml  { render :xml => @project }
    end


  end

  # GET /projects/1/edit
  def edit
      @project = Project.find_by_permalink(params[:id])
      @assets = Project.includes(:assets).find_by_permalink(params[:id])
(5 - @project.assets.length).times { @project.assets.build }
  end

  # POST /projects
  # POST /projects.json
  def create
    @project = Project.create(params[:project])


    respond_to do |format|
      if @project.save
        format.html { redirect_to @project, notice: 'Project was successfully created.' }
        format.json { render action: 'show', status: :created, location: @project }
      else
        format.html { render action: 'new' }
        format.json { render json: @project.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /projects/1
  # PATCH/PUT /projects/1.json
  def update
    @project = Project.find_by_permalink(params[:id])

    respond_to do |format|
      if @project.update(params[:project])
        format.html { redirect_to @project, notice: 'Project was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @project.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /projects/1
  # DELETE /projects/1.json
  def destroy
    @project = Project.find_by_permalink(params[:id])
    @project.destroy
    respond_to do |format|
      format.html { redirect_to projects_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_project
      @project = Project.find_by_permalink(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def project_params
      params.require(:project).permit(:title, :description, :assets_attributes)
    end

end

Answer 1

不确定这是否是错字，但请尝试在=此处添加：

<% f.fields_for :assets do |asset| %>
<%= f.fields_for :assets do |asset| %>