跳到內容 跳到搜尋
方法
H

執行個體公開方法

head(status, options = nil)

傳回沒有內容(只有標頭)的回應。選項引數會被解釋為標題名稱與值的雜湊。這讓你可以輕鬆傳回只包含重要標題的回應

head :created, location: person_path(@person)

head :created, location: @person

也可以用於回傳例外情況

return head(:method_not_allowed) unless request.post?
return head(:bad_request) unless valid_request?
render

參閱 Rack::Utils::SYMBOL_TO_STATUS_CODE 來取得所有有效 status 符號的完整清單。

# File actionpack/lib/action_controller/metal/head.rb, line 23
def head(status, options = nil)
  if status.is_a?(Hash)
    raise ArgumentError, "#{status.inspect} is not a valid value for `status`."
  end

  status ||= :ok

  if options
    location = options.delete(:location)
    content_type = options.delete(:content_type)

    options.each do |key, value|
      headers[key.to_s.split(/[-_]/).each { |v| v[0] = v[0].upcase }.join("-")] = value.to_s
    end
  end

  self.status = status
  self.location = url_for(location) if location

  if include_content?(response_code)
    unless self.media_type
      self.content_type = content_type || ((f = formats) && Mime[f.first]) || Mime[:html]
    end

    response.charset = false
  end

  self.response_body = ""

  true
end