Question

我无法影响的协议的网站向我发送POST请求，其中多个参数的名称为“t”。

这是我的request.raw_post：

--===13978193024621189109088990673===
Content-Disposition: form-data; name="t"
Content-Type: text/plain; charset=UTF-8

thevalue1
--===13978193024621189109088990673===
Content-Disposition: form-data; name="t"
Content-Type: text/plain; charset=UTF-8

thevalue2
--===13978193024621189109088990673===
Content-Disposition: form-data; name="t"
Content-Type: text/plain; charset=UTF-8

thevalue3
--===13978193024621189109088990673===
Content-Disposition: form-data; name="t"
Content-Type: text/plain; charset=UTF-8

thevalue4
--===13978193024621189109088990673===
Content-Disposition: form-data; name="t"
Content-Type: text/plain; charset=UTF-8

thevalue5
--===13978193024621189109088990673===
Content-Disposition: form-data; name="t"
Content-Type: text/plain; charset=UTF-8

thevalue6

标准params集合仅列出最后一个参数。

如何获取所有值？

重现此请求的方法是：

<form action="/updateinfo" method="post" enctype="multipart/form-data">
  <input type="text" name="t" value="thevalue1"><br>
  <input type="text" name="t" value="thevalue2"><br>
  <input type="text" name="t" value="thevalue3"><br>
  <input type="text" name="t" value="thevalue4"><br>
  <input type="text" name="t" value="thevalue5"><br>
  <input type="text" name="t" value="thevalue6"><br>
  <input type="submit">
</form>

Answer 1

最后我发现并使用了multipart-parser gem。它缺少文档，所以这里是我使用的代码：

require 'multipart_parser/reader'

module MultiParams
  def parse_multi_params(request)
    parts={}

    reader = MultipartParser::Reader.new(MultipartParser::Reader::extract_boundary_value(request.headers['CONTENT_TYPE']))

    reader.on_part do |part|
      pn = part.name.to_sym
      part.on_data do |partial_data|
        if parts[pn].nil?
          parts[pn] = partial_data
        else
          parts[pn] = [parts[pn]] unless parts[pn].kind_of?(Array)
          parts[pn] << partial_data
        end
      end
    end

    reader.write request.raw_post
    reader.ended? or raise Exception, 'truncated multipart message'

    parts
  end
end

控制器中的用法：

require 'multi_params'

class MyController < ApplicationController
  include MultiParams

  def my_method
    mp = parse_multi_params(request)
    process_params(mp[:t])
  end
end

Answer 2

请查看how rack parses incoming parameters并转换为哈希值。您可以使用raw_request并将其放入您自己的params解析器中，该解析器与机架实现非常相似，并且可以将参数t直接转换为数组。像这样的东西：

def normalize_params(params, name, v = nil)
  name =~ %r(\A[\[\]]*([^\[\]]+)\]*)
  k = $1 || ''
  after = $' || ''

  return if k.empty?

  if after == "" && k == 't'
    params[k] ||= []
    params[k] << v
  elsif == ""
    params[k] = v
  elsif after == "[]"
    params[k] ||= []
    params[k] << v
  elsif after =~ %r(^\[\]\[([^\[\]]+)\]$) || after =~ %r(^\[\](.+)$)
    child_key = $1
    params[k] ||= []
    if params_hash_type?(params[k].last)
      && !params[k].last.key?(child_key)
      normalize_params(params[k].last, child_key, v)
    else
      params[k] << normalize_params(params.class.new, child_key, v)
    end
  else
    params[k] ||= params.class.new
    params[k] = normalize_params(params[k], after, v)
  end

  return params
end

Rails：获取具有相同名称的multipart / form-data POST请求参数

2 个答案: