implemented har feature

packages/devtools_app/lib/src/screens/network/har_builder.dart

@@ -0,0 +1,153 @@
+import '../../../devtools_app.dart';
+import '../../shared/analytics/constants.dart';
+
+/// Builds a HAR (HTTP Archive) object from a list of HTTP requests.
+///
+/// The HAR format is a JSON-based format used for logging a web browser's
+/// interaction with a site. It is useful for web performance analysis and
+/// debugging. This function constructs the HAR object based on the 1.2
+/// specification.
+///
+/// For more details on the HAR format, see the [HAR 1.2 Specification](https://github.com/ahmadnassri/har-spec/blob/master/versions/1.2.md).
+///
+/// Parameters:
+/// - [httpRequests]: A list of DartIOHttpRequestData data.
+///
+/// Returns:
+/// - A Map representing the HAR object.
+Map<String, dynamic> buildHar(List<DartIOHttpRequestData> httpRequests) {
+// Build the creator
+  final creator = {
+    NetworkEventKeys.name: NetworkEventDefaults.creatorName,
+    NetworkEventKeys.creatorVersion: NetworkEventDefaults.creatorVersion,
+  };
+
+// Build the pages
+  final pages = [
+    {
+      NetworkEventKeys.startedDateTime:
+          httpRequests.first.startTimestamp.toUtc().toIso8601String(),
+      NetworkEventKeys.id: NetworkEventDefaults.id,
+      NetworkEventKeys.title: NetworkEventDefaults.title,
+      NetworkEventKeys.pageTimings: {
+        NetworkEventKeys.onContentLoad: NetworkEventDefaults.onContentLoad,
+        NetworkEventKeys.onLoad: NetworkEventDefaults.onLoad,
+      },
+    },
+  ];
+
+// Build the entries
+  final entries = httpRequests.map((e) {
+    final requestCookies = e.requestCookies.map((cookie) {
+      return {
+        NetworkEventKeys.name: cookie.name,
+        NetworkEventKeys.value: cookie.value,
+        'path': cookie.path,
+        'domain': cookie.domain,
+        'expires': cookie.expires?.toUtc().toIso8601String(),
+        'httpOnly': cookie.httpOnly,
+        'secure': cookie.secure,
+      };
+    }).toList();
+
+    final requestHeaders = e.requestHeaders?.entries.map((header) {
+      var value = header.value;
+      if (value is List) {
+        value = value.first;
+      }
+      return {
+        NetworkEventKeys.name: header.key,
+        NetworkEventKeys.value: value,
+      };
+    }).toList();
+
+    final queryString = Uri.parse(e.uri).queryParameters.entries.map((param) {
+      return {
+        NetworkEventKeys.name: param.key,
+        NetworkEventKeys.value: param.value,
+      };
+    }).toList();
+
+    final responseCookies = e.responseCookies.map((cookie) {
+      return {
+        NetworkEventKeys.name: cookie.name,
+        NetworkEventKeys.value: cookie.value,
+        'path': cookie.path,
+        'domain': cookie.domain,
+        'expires': cookie.expires?.toUtc().toIso8601String(),
+        'httpOnly': cookie.httpOnly,
+        'secure': cookie.secure,
+      };
+    }).toList();
+
+    final responseHeaders = e.responseHeaders?.entries.map((header) {
+      var value = header.value;
+      if (value is List) {
+        value = value.first;
+      }
+      return {
+        NetworkEventKeys.name: header.key,
+        NetworkEventKeys.value: value,
+      };
+    }).toList();
+
+    return {
+      NetworkEventKeys.pageref: NetworkEventDefaults.id,
+      NetworkEventKeys.startedDateTime:
+          e.startTimestamp.toUtc().toIso8601String(),
+      NetworkEventKeys.time: e.duration?.inMilliseconds,
+      NetworkEventKeys.request: {
+        NetworkEventKeys.method: e.method.toUpperCase(),
+        NetworkEventKeys.url: e.uri.toString(),
+        NetworkEventKeys.httpVersion: NetworkEventDefaults.httpVersion,
+        NetworkEventKeys.cookies: requestCookies,
+        NetworkEventKeys.headers: requestHeaders,
+        NetworkEventKeys.queryString: queryString,
+        NetworkEventKeys.postData: {
+          NetworkEventKeys.mimeType: e.contentType,
+          NetworkEventKeys.text: e.requestBody,
+        },
+        NetworkEventKeys.headersSize: NetworkEventDefaults.headersSize,
+        NetworkEventKeys.bodySize: NetworkEventDefaults.bodySize,
+      },
+      NetworkEventKeys.response: {
+        NetworkEventKeys.status: e.status,
+        NetworkEventKeys.statusText: '',
+        NetworkEventKeys.httpVersion: NetworkEventDefaults.responseHttpVersion,
+        NetworkEventKeys.cookies: responseCookies,
+        NetworkEventKeys.headers: responseHeaders,
+        NetworkEventKeys.content: {
+          NetworkEventKeys.size: e.responseBody?.length,
+          NetworkEventKeys.mimeType: e.type,
+          NetworkEventKeys.text: e.responseBody,
+        },
+        NetworkEventKeys.redirectURL: '',
+        NetworkEventKeys.headersSize: NetworkEventDefaults.headersSize,
+        NetworkEventKeys.bodySize: NetworkEventDefaults.bodySize,
+      },
+      NetworkEventKeys.cache: {},
+      NetworkEventKeys.timings: {
+        NetworkEventKeys.blocked: NetworkEventDefaults.blocked,
+        NetworkEventKeys.dns: NetworkEventDefaults.dns,
+        NetworkEventKeys.connect: NetworkEventDefaults.connect,
+        NetworkEventKeys.send: NetworkEventDefaults.send,
+        NetworkEventKeys.wait: e.duration!.inMilliseconds - 2,
+        NetworkEventKeys.receive: NetworkEventDefaults.receive,
+        NetworkEventKeys.ssl: NetworkEventDefaults.ssl,
+      },
+      NetworkEventKeys.serverIPAddress: NetworkEventDefaults.serverIPAddress,
+      NetworkEventKeys.connection: e.hashCode.toString(),
+      NetworkEventKeys.comment: '',
+    };
+  }).toList();
+
+// Assemble the final HAR object
+  return {
+    NetworkEventKeys.log: {
+      NetworkEventKeys.version: NetworkEventDefaults.logVersion,
+      NetworkEventKeys.creator: creator,
+      NetworkEventKeys.pages: pages,
+      NetworkEventKeys.entries: entries,
+    },
+  };
+}

packages/devtools_app/lib/src/screens/network/network_controller.dart

@@ -3,19 +3,23 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:devtools_app_shared/utils.dart';
 import 'package:flutter/foundation.dart';
 import 'package:vm_service/vm_service.dart';
 
+import '../../shared/config_specific/import_export/import_export.dart';
 import '../../shared/config_specific/logger/allowed_error.dart';
 import '../../shared/globals.dart';
 import '../../shared/http/http_request_data.dart';
 import '../../shared/http/http_service.dart' as http_service;
+import '../../shared/offline_data.dart';
 import '../../shared/primitives/utils.dart';
 import '../../shared/ui/filter.dart';
 import '../../shared/ui/search.dart';
 import '../../shared/utils.dart';
+import 'har_builder.dart';
 import 'network_model.dart';
 import 'network_screen.dart';
 import 'network_service.dart';
@@ -46,6 +50,7 @@ class NetworkController extends DisposableController
     with
         SearchControllerMixin<NetworkRequest>,
         FilterControllerMixin<NetworkRequest>,
+        OfflineScreenControllerMixin,
         AutoDisposeControllerMixin {
   NetworkController() {
     _networkService = NetworkService(this);
@@ -56,6 +61,34 @@ class NetworkController extends DisposableController
     );
     subscribeToFilterChanges();
   }
+  List<DartIOHttpRequestData>? _httpRequests;
+
+  String? exportAsHarFile() {
+    final exportController = ExportController();
+
+    _httpRequests =
+        filteredData.value.whereType<DartIOHttpRequestData>().toList();
+
+    if (_httpRequests!.isEmpty) {
+      debugPrint('No valid request data to export');
+      return '';
+    }
+
+    try {
+      if (_httpRequests != null && _httpRequests!.isNotEmpty) {
+        // Build the HAR object
+        final har = buildHar(_httpRequests!);
+        debugPrint('data is ${json.encode(har)}');
+        return exportController.downloadFile(
+          json.encode(har),
+          type: ExportFileType.har,
+        );
+      }
+    } catch (ex) {
+      debugPrint('Exception in export $ex');
+    }
+    return null;
+  }
 
   static const methodFilterId = 'network-method-filter';
 
@@ -360,6 +393,16 @@ class NetworkController extends DisposableController
       serviceConnection.errorBadgeManager.incrementBadgeCount(NetworkScreen.id);
     }
   }
+
+  @override
+  OfflineScreenData prepareOfflineScreenData() {
+    debugPrint('offline data - httpRequests are $_httpRequests');
+    return OfflineScreenData(
+      screenId: NetworkScreen.id,
+      //TODO deserialize har data and pass here
+      data: {},
+    );
+  }
 }
 
 /// Class for managing the set of all current websocket requests, and

packages/devtools_app/lib/src/screens/network/network_screen.dart

@@ -234,6 +234,14 @@ class _NetworkProfilerControlsState extends State<_NetworkProfilerControls>
           onPressed: widget.controller.clear,
         ),
         const SizedBox(width: defaultSpacing),
+        DownloadButton(
+          minScreenWidthForTextBeforeScaling:
+              _NetworkProfilerControls._includeTextWidth,
+          onPressed: widget.controller.exportAsHarFile,
+          gaScreen: gac.network,
+          gaSelection: gac.NetworkEvent.networkDownloadHar,
+        ),
+        const SizedBox(width: defaultSpacing),
         const Expanded(child: SizedBox()),
         // TODO(kenz): fix focus issue when state is refreshed
         SearchField<NetworkController>(

packages/devtools_app/lib/src/shared/analytics/constants.dart

@@ -12,6 +12,7 @@ part 'constants/_debugger_constants.dart';
 part 'constants/_deep_links_constants.dart';
 part 'constants/_extension_constants.dart';
 part 'constants/_memory_constants.dart';
+part 'constants/_network_constants.dart';
 part 'constants/_logging_constants.dart';
 part 'constants/_performance_constants.dart';
 part 'constants/_vs_code_sidebar_constants.dart';

packages/devtools_app/lib/src/shared/analytics/constants/_network_constants.dart

@@ -0,0 +1,79 @@
+// Copyright 2024 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+part of '../constants.dart';
+
+class NetworkEvent {
+  static const networkDownloadHar = 'networkDownloadHar';
+}
+
+class NetworkEventKeys {
+  static const log = 'log';
+  static const version = 'version';
+  static const creator = 'creator';
+  static const name = 'name';
+  static const creatorVersion = 'version';
+  static const pages = 'pages';
+  static const startedDateTime = 'startedDateTime';
+  static const id = 'id';
+  static const title = 'title';
+  static const pageTimings = 'pageTimings';
+  static const onContentLoad = 'onContentLoad';
+  static const onLoad = 'onLoad';
+  static const entries = 'entries';
+  static const pageref = 'pageref';
+  static const time = 'time';
+  static const request = 'request';
+  static const method = 'method';
+  static const url = 'url';
+  static const httpVersion = 'httpVersion';
+  static const cookies = 'cookies';
+  static const headers = 'headers';
+  static const queryString = 'queryString';
+  static const postData = 'postData';
+  static const mimeType = 'mimeType';
+  static const text = 'text';
+  static const headersSize = 'headersSize';
+  static const bodySize = 'bodySize';
+  static const response = 'response';
+  static const status = 'status';
+  static const statusText = 'statusText';
+  static const content = 'content';
+  static const size = 'size';
+  static const redirectURL = 'redirectURL';
+  static const cache = 'cache';
+  static const timings = 'timings';
+  static const blocked = 'blocked';
+  static const dns = 'dns';
+  static const connect = 'connect';
+  static const send = 'send';
+  static const wait = 'wait';
+  static const receive = 'receive';
+  static const ssl = 'ssl';
+  static const serverIPAddress = 'serverIPAddress';
+  static const connection = 'connection';
+  static const comment = 'comment';
+  static const value = 'value';
+}
+
+class NetworkEventDefaults {
+  static const logVersion = '1.2';
+  static const creatorName = 'devtools';
+  static const creatorVersion = '0.0.2';
+  static const id = 'page_0';
+  static const title = 'FlutterCapture';
+  static const onContentLoad = -1;
+  static const onLoad = -1;
+  static const httpVersion = 'HTTP/1.1';
+  static const responseHttpVersion = 'http/2.0';
+  static const headersSize = -1;
+  static const bodySize = -1;
+  static const blocked = -1;
+  static const dns = -1;
+  static const connect = -1;
+  static const send = 1;
+  static const receive = 1;
+  static const ssl = -1;
+  static const serverIPAddress = '10.0.0.1';
+}

packages/devtools_app/lib/src/shared/config_specific/import_export/import_export.dart

@@ -113,7 +113,8 @@ enum ExportFileType {
   json,
   csv,
   yaml,
-  data;
+  data,
+  har;
 
   @override
   String toString() => name;