= Moduliths Moments Moments is an implementation of the https://verraes.net/2019/05/patterns-for-decoupling-distsys-passage-of-time-event/[Passage of Time Event] idea, originally presented by https://github.com/mathiasverraes[Mathias Verraes]. It enables Spring Boot applications to consume the following events to attach business logic to them: * `DayHasPassed` - signals the end of a day * `WeekHasPassed` - signals the end of a week * `MonthHasPassed` - signals the end of a month * `QuarterHasPassed` - signals the end of a quarter * `YearHasPassed` - signals the end of a year This allows event listeners to be registered that react on the publication of such events. They allow to decouple from the actual triggering mechanism (e.g. Spring's built-in scheduling) and can thus be tested more easily. == How to use Moments? Moments will auto-activate in a Spring Boot application if you put it on the classpath of your application. [source, xml] ---- <dependency> <groupId>org.springframework.modulith</groupId> <artifactId>spring-modulith-moments</artifactId> <version>…</version> </dependency> ---- == What does Moments enable? The Moments module enables scheduling for the application it is applied to. It registers a bean of type `Moments` that takes care of publishing the above mentioned events. By setting `moduliths.moments.enable-time-machine` you can also rather expose a bean of type `TimeMachine` (which extends `Moments`), which exposes a `….shift(Duration)` method which allows to move what constitutes "now" by the given `Duration`. Moving time forward will cause all events published that would occur during the delta. === How to disable Moments? If you don't control the classpath of the application you run, you can still disable Moments by setting the `moduliths.moments.enabled` property to `false`. == Customization options Moments works with Java's standard `Clock` abstraction to determine the current time. By default, `Clock.standardUTC()` is used. To use a different clock, just register a Spring Bean of type `Clock`. Moments will pick it up automatically. === Moments configuration properties Moments exposes configuration properties to tweak its behavior under the `moduliths.moments` namespace. [%header, cols="1,1,2"] |=== |Property|Default value|Description |`enabled`|`true`|Whether to enable Moments in the first place. |`enable-time-machine`|`false`|Set to true to expose `TimeMachine` instead of `Moments` to publicly expose methods to shift time. |`granularity`|`hours`|At which granularity to publish events. Switch to `days` if you want to disable the distribution of `HourHasPassed` events. |`locale`|`Locale.default()`|The `Locale` to determine the start date of the week for `WeekHasPassed` events. |`quarter-start-month`|January|The month in which the first quarter starts. Customize via the month's name you like to start the quarters at (e.g. `February`). |`zone-id`|`UTC`|The time zone to determine the dates and times attached to the events published. Use standardized region time zone descriptors (e.g. `Europe/Berlin`) to customize |===