Optimization of Flutter network log printing

I recently started learning About Flutter. When viewing network data, I used the default Log interceptor, LogInterceptor, and found that its logs were not ideal — all on one line and not fully printed. To address these issues, I have a custom LogInterceptor

Take a look at the default interceptor’s log:

I’m used to Logger’s log format, but I can’t accept it. So I want to customize the LogInterceptor by imitating Logger’s log format

class WanLogInterceptor extends Interceptor {

  static const String TOP_LINE = "┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─";
  static const String START_LINE = "│";
  static const String SPLIT_LINE = "| ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄ ┄";
  static const String END_LINE = "└ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─";

  @override
  void onRequest(RequestOptions options, RequestInterceptorHandler handler) {
    print(TOP_LINE);
    print(START_LINE + "--> " + options.method + "" + options.uri.toString());
    print(START_LINE + 'responseType: ' + options.responseType.toString());
    print(START_LINE + 'followRedirects: ' + options.followRedirects.toString());
    print(START_LINE + 'connectTimeout: ' + options.connectTimeout.toString());
    print(START_LINE + 'sendTimeout: ' + options.sendTimeout.toString());
    print(START_LINE + 'receiveTimeout: ' + options.receiveTimeout.toString());
    print(START_LINE + 'receiveDataWhenStatusError: ' + options.receiveDataWhenStatusError.toString());
    print(START_LINE + 'extra: ' + options.extra.toString());
    print(START_LINE + "Headers: ");
    options.headers.forEach((name, values) {
      print(START_LINE + "    $name: $values");
    });
    print(END_LINE);
    handler.next(options);
  }

  @override
  void onResponse(Response response, ResponseInterceptorHandler handler) {
    print(TOP_LINE);
    print(START_LINE + "< -" + response.statusCode.toString() + "" + response.requestOptions.uri.toString());
    print(SPLIT_LINE);
    response.headers.forEach((name, values) {
      print(START_LINE + "$name: $values");
    });
    print(START_LINE + "Response Body:");
    var formatJson = JsonUtils.formatJson(response.toString());
    var splitJson = formatJson.split("\n");
    splitJson.forEach((element) {
      print(START_LINE + element);
    });
    print(END_LINE); handler.next(response); }}Copy the code

Formatting for JSON strings

class JsonUtils {

  static const int LEFT_BIG_BRACKET = 123; / / {" "
  static const int LEFT_MIDDLE_BRACKET = 91; [" / /"
  static const int RIGHT_BIG_BRACKET = 125; / / "}"
  static const int RIGHT_MIDDLE_BRACKET = 93; / / "]"
  static const int COMMA = 44; / / ","
  static const String SPACE = "";
  static const String WRAP = "\n";

  static void writeSpace(StringBuffer stringBuffer, int writeCount){
    for(int i = 1; i <= writeCount ; i++){ stringBuffer.write(SPACE); }}static String formatJson(String jsonStr) {
    var stringBuffer = StringBuffer(a);var codeUnits = jsonStr.codeUnits;
    var deep = 0;
    for(var i = 0 ; i < codeUnits.length ; i++){
      var unit = codeUnits[i];
      var string = String.fromCharCode(unit);
      switch(unit){
        case LEFT_BIG_BRACKET | LEFT_MIDDLE_BRACKET : {
          deep++;
          stringBuffer.write(string);
          stringBuffer.write(WRAP);
          writeSpace(stringBuffer, deep);
        }
        break;
        case RIGHT_BIG_BRACKET | RIGHT_BIG_BRACKET : {
          deep--;
          stringBuffer.write(WRAP);
          writeSpace(stringBuffer, deep);
          stringBuffer.write(string);
        }
        break;
        case COMMA : {
          stringBuffer.write(string);
          stringBuffer.write(WRAP);
          writeSpace(stringBuffer, deep);
        }
        break;
        default:{
          stringBuffer.write(string);
        }
        break; }}returnstringBuffer.toString(); }}Copy the code

Output effect:

That’s the end of it. The written utility class hasn’t been extensively tested and may be buggy. The test address is playing android official website, thank you.