title: Dart/Flutter: Http request raises XMLHttpRequest error
body: <p>I am trying to make an RSS reader with flutter but the program raises the <code>XMLHttpRequest error</code>.</p>
  <p>In my test I used web (Chrome) as my target platform.</p>
  <p>Thank you for your help.</p>
  <pre><code>  Future&lt;RssFeed&gt; fetchFeed() async {
  try {
    final response = await http.get(Uri.parse(url), headers: {&quot;Access-Control-Allow-Origin&quot;: &quot;*&quot;});
    return RssFeed.parse(response.body);
  } catch (e) {
    print(e);
    return RssFeed(title: &quot;Test&quot;);
    }}
  
    var feed = await fetchFeed();
  </code></pre>
  <p>Full Error Log:</p>
  <pre><code>Error: XMLHttpRequest error.
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-
  
  sdk/lib/_internal/js_dev_runtime/patch/core_patch.dart 910:28                get current
  packages/http/src/browser_client.dart 69:22                                                                                    &lt;fn&gt;
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/zone.dart 1685:54                                              runUnary
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 159:18                                        handleValue
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 766:44                                        handleValueCallback
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 795:13                                        _propagateToListeners
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 592:7                                         [_complete]
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/stream_pipe.dart 61:11                                         _cancelAndValue
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/stream.dart 1288:7                                             &lt;fn&gt;
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 334:14  _checkAndCall
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 339:39  dcall
  C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/html/dart2js/html_dart2js.dart 37301:58                              &lt;fn&gt;
  
  
      at Object.createErrorWithStack (http://localhost:49656/dart_sdk.js:5080:12)
      at Function._throw (http://localhost:49656/dart_sdk.js:20337:18)
      at Function.throwWithStackTrace (http://localhost:49656/dart_sdk.js:20334:18)
      at async._AsyncCallbackEntry.new.callback (http://localhost:49656/dart_sdk.js:40851:18)
      at Object._microtaskLoop (http://localhost:49656/dart_sdk.js:40708:13)
      at _startMicrotaskLoop (http://localhost:49656/dart_sdk.js:40714:13)
      at http://localhost:49656/dart_sdk.js:36191:9
  </code></pre>
  <p>flutter doctor output:</p>
  <pre><code>[√] Flutter (Channel stable, 2.10.1, on Microsoft Windows [Version 10.0.19042.1526], locale de-DE)
  [√] Android toolchain - develop for Android devices (Android SDK version 32.1.0-rc1)
  [√] Chrome - develop for the web
  [√] Visual Studio - develop for Windows (Visual Studio Community 2022 17.0.5)
  [√] Android Studio (version 2021.1)
  [√] VS Code (version 1.63.2)
  [√] Connected device (4 available)
  [√] HTTP Host Availability
  </code></pre>
  <p>Dependencies:</p>
  <pre><code>dependencies:
    flutter:
      sdk: flutter
  
  
  
    # The following adds the Cupertino Icons font to your application.
    # Use with the CupertinoIcons class for iOS style icons.
    cupertino_icons: ^1.0.2
    url_launcher: ^6.0.20
    http: ^0.13.0
    flutter_staggered_grid_view: ^0.6.1
    calendar_view: ^0.0.3
    webfeed: ^0.7.0
    string_similarity: ^2.0.0
    sortedmap: ^0.5.1
  </code></pre>