CODEWITHSUNDEEP
c#system.reactive
Jordi
Jordi

Reputation: 23187

Dynamic timer observable

I'm facing with an issue related with how to create a dynamic "timer" observable.

Slightly I mean, I need to perform a function and according the value it returns (integer representing the number of seconds) I need to call the same function after these seconds have elapsed. So, I guess I need to re-schedule the observable according this another new value seconds.

I've tried to find something overthere but I',ve not been able to figure out what do I need to do.

Any ideas?

Upvotes: 0

Views: 413

Answers (1)

Enigmativity
Enigmativity

Reputation: 117029

Use Observable.Generate. Try this example:

void Main()
{
    Observable
        .Generate(
            0, // initialState
            x => x < 10, //condition
            x => x + 1, //iterate
            x => x, //resultSelector
            x => TimeSpan.FromSeconds(GetSeconds())) //timeSelector
        .Timestamp()
        .Subscribe(x => Console.WriteLine($"{x.Value} {x.Timestamp}"));
}

private double _seconds = 2.0;

public double GetSeconds()
{
    if (++_seconds > 5.0)
    {
        _seconds = 2.0;
    }
    return _seconds;
}

It produces the following output:

0 2017/09/27 12:47:24 +00:00
1 2017/09/27 12:47:28 +00:00
2 2017/09/27 12:47:33 +00:00
3 2017/09/27 12:47:35 +00:00
4 2017/09/27 12:47:38 +00:00
5 2017/09/27 12:47:42 +00:00
6 2017/09/27 12:47:47 +00:00
7 2017/09/27 12:47:49 +00:00
8 2017/09/27 12:47:52 +00:00
9 2017/09/27 12:47:56 +00:00

The first result appears after 3.0 seconds (because of the initial ++seconds) and the next value after 4.0 seconds as seen by the difference in the timestamp.

It stops after 10 values due to the x => x < 10, //condition.

Upvotes: 4

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