如何在不使用图像 url 的情况下将现有缩略图数据从 Rails 发送到 Dropzone.js

Question

我是 Rails 的新手，在不使用图像 url 的情况下将现有缩略图从 Rails 发送到 Dropzone.js 时遇到问题。缩略图为 jpeg 格式，在 public 目录中不可用，因为它们位于服务器上 Rails 项目之外。

到目前为止，我可以将文件上传到服务器并进行处理。我发现 Rails 能够传递 send_file 或 send_data 形式的信息。我注意到 Dropzone.js 显示格式为

的上传缩略图

<img data-dz-thumbnail alt="..." src="data:image/png;base64...">

这是我的 Dropzone.js 初始化部分：

Dropzone.autoDiscover = false;
var dzupload = jQuery("#dZUpload"), attachments_path = $('#project_attachments_path').val();
dzupload.dropzone({
  url: "/project/upload_attachment",
  type: "POST",
  addRemoveLinks: false,
  init: function() {
    var myDropzone = this;
    jQuery.ajax({
      url: '/project/get_attachments',
      type: "POST",
      data: {id: "#{@project.id}"},
      success: function(data) {
        jQuery.each(data.attachments, function(index,val) {
          jQuery.ajax({
            url: '/project/send_thumbnail',
            type: "POST",
            data: {id: "#{@project.id}", file: val},
            success: function(file) {
              var mockFile = {
                filename: val.filename,
                name: val.original_filename,
                size: val.size,
                type: val.content_type,
                status: Dropzone.ADDED
              };
              myDropzone.emit("addedfile", mockFile);
              // This is not correct way
              myDropzone.emit("thumbnail", mockFile, file);
              myDropzone.emit("complete", mockFile);
            }
          });
        });
      }
    });
  }...
});

这是我的 Rails 部分 send_file 版本：

def send_thumbnail
  s = service_factory.new_project_service
  url = s.get_project_url(params[:id])
  send_file("#{url}/dropzone_#{params[:file][:filename]}",
    :type => params[:file][:content_type],
    :filename => params[:file][:original_filename],
    :disposition => 'inline',
    :x_sendfile => true)
end

谁能帮我解决这个问题？

Answer 1

我已经解决了这个问题！这个想法是通过 url 地址检索每个附件。收到项目附件文件名后，将设置操作路径、项目 ID 和附件以创建一个 URL 地址，从中加载缩略图。路由设置为routes.rb 文件。比如路径和action=/project/send_thumbnail，项目ID=1，文件名=123就会执行"#{project_send_thumbnail}/{#@project.id}/"+文件。

所以它就像下面这样。

Dropzone.js

Dropzone.autoDiscover = false;
var dzupload = jQuery("#dZUpload"), attachments_path = $('#project_attachments_path').val();
dzupload.dropzone({
  url: "/project/upload_attachment",
  type: "POST",
  addRemoveLinks: false,
  init: function() {
    var myDropzone = this;
    // Fetch project's attacment
    jQuery.ajax({
      url: '/project/get_attachments',
      type: "POST",
      data: {id: "#{@project.id}"},
      success: function(data) {
        jQuery.each(data.attachments, function(index,file) {
           var mockFile = {
             filename: val.filename,
             name: val.original_filename,
             size: val.size,
             type: val.content_type,
             status: Dropzone.ADDED
           };
           myDropzone.emit("addedfile", mockFile);
           // 
           myDropzone.emit("thumbnail", mockFile, "#{project_send_thumbnail_path}/#{@project.id}/"+file);
           myDropzone.emit("complete", mockFile);
        });
      }
    });
  }...
});

routes.rb

match 'project/send_thumbnail/:project_id/:file' => 'project#send_thumbnail', :as => project_send_thumbnail

project/send_thumbnail.rb

def send_thumbnail
  s = service_factory.new_project_service
  file = s.get_file(params[:project_id], params[:file])
  send_file(file[:filename],
    :type => file[:content_type],
    :filename => file[:original_filename],
    :disposition => 'inline',
    :x_sendfile => true)
end

如何在不使用图像 url 的情况下将现有缩略图数据从 Rails 发送到 Dropzone.js

How to send existing thumbnails data from Rails to Dropzone.js without using image's url

ruby-on-rails

dropzone.js