f8/sdk/dart/package-fuchsia_inspect_reader/ArchiveReader/snapshot.md

# snapshot method




    *[<Null safety>](https://dart.dev/null-safety)*




Future&lt;List&lt;[DiagnosticsData](../../package-fuchsia_inspect_reader/DiagnosticsData-class.md)&lt;METADATA>>> snapshot
({bool acceptSnapshot(List&lt;[DiagnosticsData](../../package-fuchsia_inspect_reader/DiagnosticsData-class.md)&lt;METADATA>> snapshot)?, Duration attemptDelay = const Duration(milliseconds: 100), int? maxAttempts = 200})





<p>Obtain a snapshot of the current inspect data as constrained by
<code>selector</code>.</p>
<p>The return value is the json object returned by <code>FormattedContent.json</code> as
parsed by <code>jsonDecode</code>.</p>
<p>If <code>acceptSnapshot</code> is not null, this method returns a snapshot once
<code>acceptSnapshot</code> returns true.  If <code>maxAttempts</code> is not null, at most
<code>maxAttempts</code> are made to obtain a snapshot.  <code>delay</code> controls the delay
between snapshot attempts.</p>



## Implementation

```dart
Future<List<DiagnosticsData<METADATA>>> snapshot(
    {bool acceptSnapshot(List<DiagnosticsData<METADATA>> snapshot)?,
    Duration attemptDelay = const Duration(milliseconds: 100),
    int? maxAttempts = 200}) async {
  for (var attempts = 0;
      maxAttempts == null || attempts < maxAttempts;
      attempts++) {
    final snapshot = await _snapshotAttempt;
    if (acceptSnapshot == null || acceptSnapshot(snapshot)) {
      return snapshot;
    }
    await Future.delayed(attemptDelay);
  }
  throw Exception('snapshot failed');
}
```