Dart从base64转换整个json树

Question

我有每个值都编码为base64的json。 我想遍历整个树并解码每个值。 这需要是自动的。 在代码中不能指定json键。 它需要自行下降。 我该怎么办？

这就是我到目前为止

Map<String, dynamic> parseJson(String response) {
  var data = json.decode(response);

  // Here I need to decode from base64

  return data;
}

这就是json的样子

{
   "app_title":"RnJpU8Okaw==",
   "app_color":"I0ZGRUUzMw==",
   "app_tabs":[
      {
         "title":"RW4gdGl0ZWwgw6XDpMO2w4XDhMOW",
         "content":"CkxpdGUgaW5uZWjDpWxsLiA8YnIgLz4gCjxiPmhlajwvYj4gCjxoMT50ZXN0PC9oMT4KPGEgaHJlZj0iaHR0cDovL2ZyaXNrb2xhLm51Ij5FbiBsw6RuazwvYT4KPGRpdiBzdHlsZT0iY29sb3I6IGdyZWVuIj5MaXRlIGdyw7ZuIHRleHQga2Fuc2tlPzwvZGl2Pgo8aW1nIHNyYz0iaHR0cDovL2ZyaXNrb2xhLm51L2ltYWdlcy9zb2ZyaV9sb2dvdHlwLnBuZyIgLz4K"
      },
      {
         "title":"RW4gdGl0ZWwgw6XDpMO2w4XDhMOW",
         "content":"CkxpdGUgaW5uZWjDpWxsLiA8YnIgLz4gCjxiPmhlajwvYj4gCjxoMT50ZXN0PC9oMT4KPGEgaHJlZj0iaHR0cDovL2ZyaXNrb2xhLm51Ij5FbiBsw6RuazwvYT4KPGRpdiBzdHlsZT0iY29sb3I6IGdyZWVuIj5MaXRlIGdyw7ZuIHRleHQga2Fuc2tlPzwvZGl2Pgo8aW1nIHNyYz0iaHR0cDovL2ZyaXNrb2xhLm51L2ltYWdlcy9zb2ZyaV9sb2dvdHlwLnBuZyIgLz4K"
      },
      {
         "title":"RW4gdGl0ZWwgw6XDpMO2w4XDhMOW",
         "content":"CkxpdGUgaW5uZWjDpWxsLiA8YnIgLz4gCjxiPmhlajwvYj4gCjxoMT50ZXN0PC9oMT4KPGEgaHJlZj0iaHR0cDovL2ZyaXNrb2xhLm51Ij5FbiBsw6RuazwvYT4KPGRpdiBzdHlsZT0iY29sb3I6IGdyZWVuIj5MaXRlIGdyw7ZuIHRleHQga2Fuc2tlPzwvZGl2Pgo8aW1nIHNyYz0iaHR0cDovL2ZyaXNrb2xhLm51L2ltYWdlcy9zb2ZyaV9sb2dvdHlwLnBuZyIgLz4K"
      }
   ]
}

谢谢！

Answer 1

这是使用Base64Codec ，如果使用utf8.decode ，则不会丢失编码。

  import 'dart:convert';

  Base64Codec base64 = const Base64Codec();
Map<String, dynamic> parseJson(String response) {
    final data = json.decode(response);

    // Here I need to decode from base64
    final dataTitle = data["app_title"];
    final dataColor = data["app_color"];


    //decode base64
    final dataTitle64 = base64.decode(dataTitle);
    final dataColor64 = base64.decode(dataColor);


    //Strings
    String stringTitle = utf8.decode(dataTitle64);
    String stringColor = utf8.decode(dataColor64);


    //content array
    List<Item> list = List();
    for (Map<String, dynamic> value in data["app_tabs"]){
       final mapTitle = base64.decode(value["title"]);
       final mapContent = base64.decode(value["content"]);
       String stringTitle = utf8.decode(mapTitle);
       String stringContent = utf8.decode(mapContent);
       list.add(Item(stringTitle, stringContent));
    }

    //now you have your list of items

    for(Item item in list){
       print("ITEM: ${item.title} .. ${item.content}");
    }
    //return that list if you want


    return data;
  }

Answer 2

我最终自己解决了！ 这是最终代码：

import 'dart:async';
import 'dart:convert';

import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;


Future<Map<String, dynamic>> fetchJson() async {
  final res = await http.get('http://app.roboro.se/json/001');

  if (res.statusCode == 200) {
    return compute(parseJson, res.body);
  } else {
    throw Exception('Failed to load json');
  }
}


Map<String, dynamic> parseJson(String response) {    
  return walkJson(json.decode(response));
}


Map<String, dynamic> walkJson(data) {
  data.forEach((key, value) {
    if (value is List == false) {
      data[key] = base64Decode(value);  
    } else {
      value.forEach((item) => item = walkJson(item));
    }
  });

  return data;
}


String base64Decode(String encoded) {
  return utf8.decode(base64.decode(encoded));
}