Tempo.Event.Resolver behaviour (Tempo v2.1.1)

A behaviour for a consumer's own computed events, written (name)e in a selection beside the built-ins of Tempo.Event.

A resolver names the events it owns with known/0 and computes each one's date with date/3, and is registered with config :ex_tempo, :event_resolvers, [MyApp.Events]. The registry is read each time a date is asked, so it may be set at compile time or at runtime; the first resolver whose known/0 claims a name computes it.

defmodule MyApp.Events do
  @behaviour Tempo.Event.Resolver

  @impl true
  def known, do: ["fiscal-year-start"]

  @impl true
  def date("fiscal-year-start", year, _calendar), do: Date.new(year, 4, 1)
  def date(_name, _year, _calendar), do: {:error, :unknown_event}
end

Summary

Callbacks

date(name, year, calendar)

The date of a named event in a Gregorian year, {:ok, date} in Calendar.ISO or {:error, reason}. Tempo.Event.date/3 returns the reason as that of a Tempo.InvalidDateError, and an exception as it is.

known()

The event names this resolver computes.

Callbacks

date(name, year, calendar)

@callback date(name :: String.t(), year :: integer(), calendar :: module()) ::
  {:ok, Date.t()} | {:error, term()}

known()

@callback known() :: [String.t()]

The event names this resolver computes.