Handling async operations in a synchronous ITimeZoneProvider interface

[McahitKutsal]

Hello,

I’m trying to implement ITimeZoneProvider in order to provide correct timezone offset values based on the user’s browser. For this, I need to call a IJSRuntime function as shown below, but doing so causes a deadlock.

Converting GetTimeZone() into Task would violate the existing interface contract, so I’m looking for advice on the best way to integrate asynchronous runtime calls in a design where the interface is synchronous. @sfmskywalker

Best Regards
Mücahit

public TimeZoneInfo GetTimeZone()
{
    if (_userOffset == null)
    {
        int offsetInMinutes = _jsRuntime.InvokeAsync<int>("blazorGetTimezoneOffset").ConfigureAwait(false).GetAwaiter().GetResult();
        _userOffset = TimeSpan.FromMinutes(-offsetInMinutes);
    }

    var offset = _userOffset.Value;
    string displayName = $"UTC{(offset >= TimeSpan.Zero ? "+" : "")}{offset:hh\\:mm}";
    string standardName = $"Client Local Time ({displayName})";

    return TimeZoneInfo.CreateCustomTimeZone(
        id: displayName,
        baseUtcOffset: offset,
        displayName: displayName,
        standardDisplayName: standardName
    );
}

[sfmskywalker]

Makes sense. Best would be to refactor the timeline provider interface to support async. Please feel free to raise a PR to that effect. Alternatively, we’ll take care of it, at some point.