Rails 4添加file_field以将附件上传到现有表单和控制器 [英] Rails 4 add file_field for attachment upload to existing form and controller

问题描述

我是Rails的新手.现在已经学习了几个星期.请原谅我的白痴.我无法选择选择上传的文件.

I'm super new to rails. Been learning a few weeks now. Please excuse my idiocy. I cannot get my file I've selected to upload.

我正在使用Rails 4.0.0.

I'm using Rails 4.0.0.

我正在第一个应用程序上工作，我首先遵循了博客应用程序的rails指南.我接受并运行了它，并尝试尝试学习如何创建一个与众不同的(错误跟踪系统).

I am working on my first application, and I started by following the rails guide for the blog application. I took that and ran with it and am creating something different (bug tracking system) just trying to learn to ropes.

所以，我有自己的表格:

So, I've got my form:

<%= form_for @post do |f| %>

，并且我已经在file_field中添加了.从视图中看的显示部分在选择文件方面看起来和效果都很好.

and I've added in my file_field. The display part in from the view looks and works good as far as selecting a file goes.

<%= f.label :attachment %>
<%= f.file_field :attachment %>

我已将其从导轨4上仅供参考.所以我的控制器看起来像这样:

I've pulled this from the rails 4 guides FYI. So my controller looks like this:

class PostsController < ApplicationController

    def new
      @post = Post.new
    end

    def create
      @post = Post.new(params[:post].permit(:title, :text, :user, :screen))

      if @post.save
        redirect_to posts_path
      else
        render 'new'
      end
    end

    def show
      @post = Post.find(params[:id])
    end

    def index
      @posts = Post.all
    end

    def edit
      @post = Post.find(params[:id])
    end

    def update
      @post = Post.find(params[:id])

      if @post.update(params[:post].permit(:title, :text, :user, :screen))
        redirect_to posts_path
      else
        render 'edit'
      end
    end

    def destroy
      @post = Post.find(params[:id])
      @post.destroy
      redirect_to posts_path
    end

    def upload
      uploaded_io = params[:post][:attachment]
      File.open(Rails.root.join('public', 'uploads', uploaded_io.original_filename), 'w') do |file|
        file.write(uploaded_io.read)
      end
    end

    private
    def post_params
      params.require(:post).permit(:title, :text, :user, :screen, :attachment)
    end

end

此处的新片段已上传.通过数据库进行写入/读取以及显示其他所有内容，都可以正常工作.当显示视图时，我输入文本，附加一个文件，然后单击提交".一切都写入数据库并显示在索引上，但是我尝试附加的文件未写入〜/bugs/public/uploads/

The new piece in here is upload. Everything else is working fine with writing/reading from the database and displaying. When the view is displayed I make text entries, attached a file and hit submit. Everything writes to the database and shows up on index, but the file I've attempted to attached does not get written to ~/bugs/public/uploads/

预先感谢您的帮助.

推荐答案

我认为问题可能是::attachment属性不是创建"或更新"操作中的允许参数.

I think the problem might be that the :attachment attribute is not a permitted parameter in the "create" or "update" action.

我执行简单文件上传的方法是使用 Paperclip gem-此 railscast 解释得很好.真的很容易使用.

The way I do simple file uploads is with the Paperclip gem - this railscast explains it well. It's really easy to use.

还有此答案可以回答该问题.

此外，使用强参数的标准方法是在私有方法中定义允许的参数，并在控制器操作中调用该方法(因此您不必重复自己).这可能是导致错误的原因.

Also, the standard way to use strong parameters is defining permitted params in a private method and calling that method in the controller action (so you don't have to repeat yourself). That might be the cause of the error.

示例:

def create
  @post = Post.new(post_params)
  ...
end

希望有帮助.

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