first commit

web/main.dart

@@ -0,0 +1,18 @@
+import 'dart:convert';
+import 'dart:html';
+
+void main() {
+  querySelector("#format").onClick.listen((event) {
+    TextAreaElement e = querySelector("#json");
+    var string = e.value;
+    var pretty = formatJson(string);
+    e.value = pretty;
+  });
+}
+
+String formatJson(String jsonString) {
+  var map = json.decode(jsonString);
+  var prettyStringList = JsonUtf8Encoder(" ").convert(map);
+  var prettyString = String.fromCharCodes(prettyStringList);
+  return prettyString;
+}