Ruby on Rails - 双渲染错误 - 重定向和返回

Question

错误：AbstractController::DoubleRenderError（在此操作中多次调用渲染和/或重定向。请注意，您只能调用渲染或重定向，并且每个操作最多调用一次。另请注意，重定向和渲染都不会终止执行动作，所以如果你想在重定向后退出动作，你需要执行类似“redirect_to(...) and return”的操作。）

更新时，模型检查 template.exists？，如果为 true，则下载报告并重定向到父对象。否则，只需重定向即可。

我在“if”语句的切线一侧使用“and return”，那么为什么它没有按预期工作？

def update
  template = resource.check_changes(params[:well_master])
  paramString = resource.to_json
  
  update! do |format|
    if resource.errors.present?
      return render :edit
    else
      if template != ''
        generateWellLetter(template, 'Rpt_Farm_Name', paramString) 
      else
        rec = resource.PERMIT
        format.html { redirect_to admin_well_master_path(rec) }
      end
    end
  end
end
 
def generateWellLetter(template, letterName, params)
  @URL = "#{ENV["API_HOST"]}/api/Document/Generate/#{template}"
  response = HTTParty.post(@URL,
     :body => params,
     :headers => { "Content-Type" => "application/json" })

  Zip::InputStream.open(StringIO.new(response)) do |io|
    while entry = io.get_next_entry
      report = io.read
      send_data report, :filename => letterName + '.docx', :type => 'docx'
    end
  end

  respond_to do |format|
    rec = resource.PERMIT
    format.html { redirect_to admin_well_master_path(rec) } and return
  end
end

Answer 1

您渲染了很多次，我建议将所有渲染调用集中在一起。

# send_data is like render, you can only call it once
while entry = io.get_next_entry
  report = io.read
  send_data report, filename: letterName + ".docx", type: "docx"
end

# can't send_data and also render
#
# can't use respond_to and respond_with (from inherited_resources -> responders)
# that's what `update!` method is for
#
# returning inside of the respond_to block means 
# `redirect_to admin_well_master_path(rec)` never runs
respond_to do |format|
  rec = resource.PERMIT
  format.html { redirect_to admin_well_master_path(rec) } and return
end

---

如果您使用继承的资源，那么您可能应该使用它，否则，它没有帮助，您应该只使用

respond_to

块与您自己的逻辑。

def update
  template = resource.check_changes(params[:well_master])
  update! do |success, failure|
    # failure - already renders :edit so it's not needed
    success.html do
      if template.present?
        generate_well_letter(template, resource.to_json) do |report|
          send_data report, filename: "Rpt_Farm_Name.docx", type: "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
        end
      else
        redirect_to admin_well_master_path(resource.PERMIT)
      end
    end
  end
end

def generate_well_letter(template, json)
  url = "#{ENV["API_HOST"]}/api/Document/Generate/#{template}"
  response = HTTParty.post(url, body: json, headers: {"Content-Type" => "application/json"})

  # either you're sending the whole zip file or just one file from the zip file
  Zip::InputStream.open(response) do |io|
    entry = io.get_next_entry
    report = entry.get_input_stream.read
    yield report
  end
end

https://github.com/activeadmin/inherited_resources#overwriting-actions