Swift中如何高效解析含HTML的API响应至PolicyEntity实体？

问题背景 #

API返回的是Swift对象的Debug描述字符串（格式如Optional(SBKK.PolicyEntity(errorCode: Optional("222"), message: nil, httpBody: Optional("<html>...</html>")))），当前只能通过字符串索引截取解析，需要更可靠的方式将其转换为PolicyEntity实体，最终提取httpBody内容展示在WebView中。

最优解决方案优先级 #

1. 修正API返回格式（推荐）
   直接要求后端返回标准JSON格式，示例如下：

   {"errorCode":"222","message":null,"httpBody":"<html><meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">...</html>"}
   

   这种情况下，PolicyEntity的Decodable协议可直接生效，无需额外处理：

   AF.request(request).responseDecodable(of: PolicyEntity.self) { response in
       switch response.result {
       case .success(let model):
           successHandler(model as! T)
       case .failure(let error):
           print("解析失败: \(error)")
           failHandler(ErrorCode())
       }
   }
   

2. 自定义Debug字符串解析（API无法修改时）
   利用正则表达式提取字段值，给PolicyEntity添加自定义初始化方法适配Debug字符串格式：

   extension PolicyEntity {
       init?(fromDebugString string: String) {
           // 提取errorCode
           let errorCodePattern = #"errorCode: Optional\((\"?)(.*?)\1\)"#
           let errorCodeMatch = string.range(of: errorCodePattern, options: .regularExpression)
           errorCode = errorCodeMatch.flatMap {
               let capture = string[$0].replacingOccurrences(of: errorCodePattern, with: "$2", options: .regularExpression)
               return capture.isEmpty ? nil : capture
           }
           
           // 提取message
           let messagePattern = #"message: (nil|Optional\((\"?)(.*?)\2\))"#
           let messageMatch = string.range(of: messagePattern, options: .regularExpression)
           if let matchRange = messageMatch {
               let messagePart = string[matchRange].replacingOccurrences(of: messagePattern, with: "$1", options: .regularExpression)
               if messagePart == "nil" {
                   message = nil
               } else {
                   let content = messagePart.replacingOccurrences(of: #"Optional\((\"?)(.*?)\1\)"#, with: "$2", options: .regularExpression)
                   message = content.isEmpty ? nil : content
               }
           } else {
               message = nil
           }
           
           // 提取httpBody并还原转义字符
           let httpBodyPattern = #"httpBody: Optional\((\"?)([\s\S]*?)\1\)"#
           let httpBodyMatch = string.range(of: httpBodyPattern, options: .regularExpression)
           httpBody = httpBodyMatch.flatMap {
               var content = string[$0].replacingOccurrences(of: httpBodyPattern, with: "$2", options: .regularExpression)
               // 还原转义的双引号
               content = content.replacingOccurrences(of: "\\\"", with: "\"")
               return content.isEmpty ? nil : content
           }
       }
   }
   

   在请求方法中替换原解析逻辑：

   case .success:
       guard let responseString = response.value, let model = PolicyEntity(fromDebugString: responseString) else {
           print("AF.request failure")
           failHandler(ErrorCode())
           return
       }
       successHandler(model as! T)
   

注意事项 #

• 正则解析依赖Debug字符串的格式稳定性，若后端修改结构体的Debug输出（如字段顺序、命名），解析逻辑需同步调整。
• 优先选择API返回标准JSON，这是最可靠、可维护的方案。

内容的提问来源于stack exchange，提问作者Marcel Kopera