Flutter Config toJson/fromJson (#1893)

flutter/sherpa_onnx/lib/src/online_punctuation.dart

@@ -11,6 +11,16 @@ class OnlinePunctuationModelConfig {
       this.provider = 'cpu',
       this.debug = true});
 
+  factory OnlinePunctuationModelConfig.fromJson(Map<String, dynamic> json) {
+    return OnlinePunctuationModelConfig(
+      cnnBiLstm: json['cnnBiLstm'],
+      bpeVocab: json['bpeVocab'],
+      numThreads: json['numThreads'],
+      provider: json['provider'],
+      debug: json['debug'],
+    );
+  }
+
   @override
   String toString() {
     return 'OnlinePunctuationModelConfig(cnnBiLstm: $cnnBiLstm, '
@@ -18,6 +28,16 @@ class OnlinePunctuationModelConfig {
         'provider: $provider, debug: $debug)';
   }
 
+  Map<String, dynamic> toJson() {
+    return {
+      'cnnBiLstm': cnnBiLstm,
+      'bpeVocab': bpeVocab,
+      'numThreads': numThreads,
+      'provider': provider,
+      'debug': debug,
+    };
+  }
+
   final String cnnBiLstm;
   final String bpeVocab;
   final int numThreads;
@@ -30,11 +50,23 @@ class OnlinePunctuationConfig {
     required this.model,
   });
 
+  factory OnlinePunctuationConfig.fromJson(Map<String, dynamic> json) {
+    return OnlinePunctuationConfig(
+      model: OnlinePunctuationModelConfig.fromJson(json['model']),
+    );
+  }
+
   @override
   String toString() {
     return 'OnlinePunctuationConfig(model: $model)';
   }
 
+  Map<String, dynamic> toJson() {
+    return {
+      'model': model.toJson(),
+    };
+  }
+
   final OnlinePunctuationModelConfig model;
 }
 
@@ -90,7 +122,7 @@ class OnlinePunctuation {
     final ans = p.toDartString();
 
     SherpaOnnxBindings.sherpaOnnxOnlinePunctuationFreeText?.call(p);
-    
+
     return ans;
   }