Simple samples for dummies

[Berad]

Hi there!
I've read introduction, get started, etc. Still I can't find any dummy samples.

In my case I need to retry getting some value from my database, i.e. now I have

MyCustomType myValue = await dbContext.TryGetMyValueByIdAsync(id);

where TryGetMyValueByIdAsync can return null and it's ok after several attempts.
And I was looking for something like

MyCustomType myValue = pipeline.ExecuteAsync<MyCustomType>( token => {
    dbContext.TryGetMyValueByIdAsync(id, token)); 
});

I don't need to get any exceptions, I just want to retry to get a value several times and if it's null -- ok, I will deal with it.

Could you please help me with that?

[martincostello]

For your use case it looks like you want a fallback strategy with something similar to:

var options = new FallbackStrategyOptions<MyCustomType>
{
    ShouldHandle = new PredicateBuilder<MyCustomType>().Handle<Exception>(),
    FallbackAction = static args => Outcome.FromResultAsValueTask((MyCustomType)null)
};

var pipeline = new ResiliencePipelineBuilder<MyCustomType>().AddFallback(options);

MyCustomType myValue = pipeline.ExecuteAsync<MyCustomType>(
    token => dbContext.TryGetMyValueByIdAsync(id, token));

[Berad]

Almost!
Thank you for your answer, you helped me to realize that I actually need a combination of fallback and retry!
I found it on the page you've linked. Very appreciated!