Future _loadAndShowGist()

in lib/embed.dart [606:688]
72 lines of code
15 McCabe index (conditional complexity)

  Future<void> _loadAndShowGist({bool analyze = true}) async {
    if (gistId!.isEmpty && sampleId.isEmpty && !githubParamsPresent) {
      print('Cannot load gist: neither id, sample_id, nor GitHub repo info is '
          'present.');
      return;
    }

    editorIsBusy = true;

    final loader = deps[GistLoader] as GistLoader?;

    try {
      Gist gist;

      if (gistId!.isNotEmpty) {
        gist = await loader!.loadGist(gistId);
      } else if (sampleId.isNotEmpty) {
        // Right now, there are only two hosted versions of the docs: master and
        // stable. Default to stable for dev and beta.
        final channel = (sampleChannel == FlutterSdkChannel.master)
            ? FlutterSdkChannel.master
            : FlutterSdkChannel.stable;
        gist = await loader!.loadGistFromAPIDocs(sampleId, channel);
      } else {
        gist = await loader!.loadGistFromRepo(
          owner: githubOwner,
          repo: githubRepo,
          path: githubPath,
          ref: githubRef,
        );
      }

      setContextSources(<String, String>{
        'main.dart': gist.getFile('main.dart')?.content ?? '',
        'index.html': gist.getFile('index.html')?.content ?? '',
        'styles.css': gist.getFile('styles.css')?.content ?? '',
        'solution.dart': gist.getFile('solution.dart')?.content ?? '',
        'test.dart': gist.getFile('test.dart')?.content ?? '',
        'hint.txt': gist.getFile('hint.txt')?.content ?? '',
      });

      if (analyze) {
        unawaited(performAnalysis());
      }

      if (autoRunEnabled) {
        unawaited(handleRun());
      }
    } on GistLoaderException catch (ex) {
      // No gist was loaded, so clear the editors.
      setContextSources(<String, String>{});

      if (ex.failureType == GistLoaderFailureType.contentNotFound) {
        await dialog.showOk(
            'Error loading gist',
            'No gist was found for the gist ID, sample ID, or repository '
                'information provided.');
      } else if (ex.failureType == GistLoaderFailureType.rateLimitExceeded) {
        await dialog.showOk(
            'Error loading files',
            'GitHub\'s rate limit for '
                'API requests has been exceeded. This is typically caused by '
                'repeatedly loading a single page that has many DartPad embeds or '
                'when many users are accessing DartPad (and therefore GitHub\'s '
                'API server) from a single, shared IP address. Quotas are '
                'typically renewed within an hour, so the best course of action is '
                'to try back later.');
      } else if (ex.failureType ==
          GistLoaderFailureType.invalidExerciseMetadata) {
        if (ex.message != null) {
          print(ex.message);
        }
        await dialog.showOk(
            'Error loading files',
            'DartPad could not load the requested exercise. Either one of the '
                'required files wasn\'t available, or the exercise metadata was '
                'invalid.');
      } else {
        await dialog.showOk('Error loading files',
            'An error occurred while the requested files.');
      }
    }
  }