Table of Contents

AverageStrategy Class

Definition

Namespace
Bodu.Financial.ExchangeRates.Caching
Assembly
Bodu.Financial.ExchangeRates.Caching.dll
Package
Bodu.Financial.ExchangeRates.Caching 1.0.0
Source
AverageStrategy.cs

An IRateAggregationStrategy that returns the arithmetic mean of every candidate that can resolve the request, tagged with a synthetic provider label.

public sealed class AverageStrategy : IRateAggregationStrategy
Inheritance
AverageStrategy
Implements
Inherited Members
Extension Methods

Remarks

The mean is computed in decimal over the forward rates each candidate returns (each candidate has already resolved its own inverse, so the synthesized rate is never itself inverted) and is not pre-rounded; rounding is deferred to the money boundary. The synthesized observation is dated at the requested date, and its reported offset is the largest offset among the contributing candidates.

Averaging is most meaningful with Exact, where every contributor shares the requested date; under fallback resolutions the contributors may have resolved different dates. The range overload averages only the dates present in every contributing candidate (an inner join by date).

The synthesized mean is an analytical, composite value, not an authoritative observation: it can differ from every contributor and so may equal a rate that no source actually published, and under a fallback resolution it can blend observations the contributors resolved on different dates. It is well suited to smoothing or cross-source comparison, but a consumer that needs a rate a specific source actually published - for tax, accounting, audit, or other compliance use - should prefer a single source (for example through PriorityFallbackStrategy or per-pair routing) rather than this strategy. 

using Bodu.Financial.ExchangeRates;
using Bodu.Financial.ExchangeRates.Caching;

var aggregate = new AggregatingRateProvider(
    new[]
    {
        new NamedDatedRateProvider("BankA", bankA),
        new NamedDatedRateProvider("BankB", bankB),
    },
    new RateAggregationOptions { DefaultStrategy = new AverageStrategy() });

// The mean of every contributor, under the synthetic "Average" provider label.
RateLookupResult averaged = aggregate.GetRate("AUD", "USD", new DateOnly(2024, 3, 15));

Constructors

AverageStrategy(string)

Initializes a new instance of the AverageStrategy class.

public AverageStrategy(string providerLabel = "Average")

Parameters

providerLabel string

The provider label applied to each synthesized average rate.

Exceptions

ArgumentNullException

Thrown when providerLabel is null.

ArgumentException

Thrown when providerLabel is empty or white space.

Fields

DefaultProviderLabel

The default provider label applied to a synthesized average rate.

public const string DefaultProviderLabel = "Average"

Field Value

string

Properties

ProviderLabel

Gets the provider label applied to each synthesized average rate.

public string ProviderLabel { get; }

Property Value

string

The synthetic provider label.

Methods

AggregateRange(string, string, DateOnly, DateOnly, IReadOnlyList<NamedDatedRateProvider>)

Combines the candidates' rates over the inclusive date range startDate to endDate synchronously.

public IReadOnlyList<ExchangeRate> AggregateRange(string fromIsoCode, string toIsoCode, DateOnly startDate, DateOnly endDate, IReadOnlyList<NamedDatedRateProvider> candidates)

Parameters

fromIsoCode string

The source-currency ISO code.

toIsoCode string

The destination-currency ISO code.

startDate DateOnly

The inclusive start of the range.

endDate DateOnly

The inclusive end of the range.

candidates IReadOnlyList<NamedDatedRateProvider>

The ordered candidate providers to combine.

Returns

IReadOnlyList<ExchangeRate>

The combined rates ordered by date, or an empty list when none are available.

Remarks

This member lets the aggregator's synchronous range surface stay synchronous rather than block on AggregateRangeAsync(string, string, DateOnly, DateOnly, IReadOnlyList<NamedDatedRateProvider>, CancellationToken). The default implementation blocks on the asynchronous overload as a compatibility fallback for strategies that supply only the asynchronous combination; the built-in strategies override it with a genuinely synchronous implementation. Override it whenever the candidates expose a synchronous range surface.

AggregateRangeAsync(string, string, DateOnly, DateOnly, IReadOnlyList<NamedDatedRateProvider>, CancellationToken)

Combines the candidates' rates over the inclusive date range startDate to endDate.

public ValueTask<IReadOnlyList<ExchangeRate>> AggregateRangeAsync(string fromIsoCode, string toIsoCode, DateOnly startDate, DateOnly endDate, IReadOnlyList<NamedDatedRateProvider> candidates, CancellationToken cancellationToken)

Parameters

fromIsoCode string

The source-currency ISO code.

toIsoCode string

The destination-currency ISO code.

startDate DateOnly

The inclusive start of the range.

endDate DateOnly

The inclusive end of the range.

candidates IReadOnlyList<NamedDatedRateProvider>

The ordered candidate providers to combine.

cancellationToken CancellationToken

A token to observe while awaiting the operation.

Returns

ValueTask<IReadOnlyList<ExchangeRate>>

The combined rates ordered by date, or an empty list when none are available.

TryAggregate(string, string, DateOnly, RateLookupOptions, IReadOnlyList<NamedDatedRateProvider>, out RateLookupResult)

Attempts to resolve a single-date rate from the supplied candidates.

public bool TryAggregate(string fromIsoCode, string toIsoCode, DateOnly date, RateLookupOptions options, IReadOnlyList<NamedDatedRateProvider> candidates, out RateLookupResult result)

Parameters

fromIsoCode string

The source-currency ISO code.

toIsoCode string

The destination-currency ISO code.

date DateOnly

The calendar date for which a rate is required.

options RateLookupOptions

The lookup rules to apply; never null.

candidates IReadOnlyList<NamedDatedRateProvider>

The ordered candidate providers to combine.

result RateLookupResult

When this method returns true, the resolved result.

Returns

bool

true when the candidates yielded a rate; otherwise false.

Applies to

ProductVersions
.NET8, 10