如何在rails上的ruby上传文件？

Posted 2021-03-28

我在铁轨上的红宝石很新。我遇到了问题。我想创建一个文件上传功能，通过它我可以上传任何类型的文件（文本，图像等）。我的控制器文件是（upload_controller.rb）：

class UploadController < ApplicationController
def index
    render :file => 'appviewsuploaduploadfile.html.erb'
end
def uploadFile
    post = DataFile.save(params[:upload])
    render :text => "File has been uploaded successfully"
end
end

我的模型文件是（data_file.rb）：

class DataFile < ActiveRecord::Base
    attr_accessor :upload
  def self.save(upload)
    name = upload['datafile'].original_filename
    directory = 'public/data'
    # create the file path
    path = File.join(directory,name)
    # write the file
    File.open(path, "wp") { |f| f.write(upload['datafile'].read)}
  end
end

我的View文件是（uploadfile.html.erb）：

<h1>File Upload</h1>
<%= form_tag({:action => 'uploadFile'}, :multipart => true) do %>
<p><label for="upload_file">Select File</label>
<%= file_field 'upload', 'datafile' %></p>
<%= submit_tag "Upload" %>
<% end %>

现在，当我尝试上传图像时，我在模型文件中收到错误“无效访问模式wp”。当我在模型文件中将File.open（path，“wp”）更改为File.open（path，“w”）时，这会将“' x89'从ASCII-8BIT更改为UTF-8”。对于.txt文件，它工作正常。我正在使用ruby 1.9.3和rails 3.2.6

答案

谢谢你，我也研究过rails！

它适用于rails 3.1

我的代码：

Routes
resources :images do
      collection { post :upload_image }
    end

调节器

class ImagesController < ApplicationController
  def index
    @car = Car.find(params[:car_id])
    @images = @car.images.order("order_id")
  end

  def upload_image   
    DataFile.save_file(params[:upload])
    redirect_to images_path(:car_id => params[:car_id])
  end

查看index.html.erb

<h1>File Upload</h1>
  <%= form_tag({:action => 'upload_image', :car_id => @car.id}, :multipart => true) do %>
    <p><label for="upload_file">Select File</label>
    <%= file_field 'upload', 'datafile' %></p>
    <%= submit_tag "Upload" %>
  <% end %>

  <% @images.each do |image| %>
     <%= image.id %><br/>
     <%= image.name %>
  <% end %>

模型

class DataFile < ActiveRecord::Base
    attr_accessor :upload

  def self.save_file(upload)   

    file_name = upload['datafile'].original_filename  if  (upload['datafile'] !='')    
    file = upload['datafile'].read    

    file_type = file_name.split('.').last
    new_name_file = Time.now.to_i
    name_folder = new_name_file
    new_file_name_with_type = "#{new_name_file}." + file_type

    image_root = "#{RAILS_CAR_IMAGES}"


    Dir.mkdir(image_root + "#{name_folder}");
      File.open(image_root + "#{name_folder}/" + new_file_name_with_type, "wb")  do |f|  
        f.write(file) 
      end

  end
end

另一答案

问题的原因是编码问题。您似乎正在以ASCII-8BIT模式读取文件并以UTF-8编写，这意味着需要进行转换。从ASCII-8BIT到UTF-8的转换并不是直截了当的。或者，您可以为读取和写入文件指定二进制模式。

upload_file = File.new(<original file>, "rb").read

和

File.open(<final uploaded file>, "wb") {|f| f.write(upload_file) }

另一答案

用“wb”代替“wp”。有用

File.open(path, "wb") { |f| f.write(upload['datafile'].read)}

另一答案

另一个很好的选择是carrierwave，安装非常简单，github上的指南可以在几分钟内启动并运行。将它添加到您的gemfile然后运行bundle install

关于这个问题，还有一个很好的railscast