event_bus

# Changelog
All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).

## [1.7.X] 2022-01-02
- Doc enhancements by @kianmeng
- Apply credo library suggestions
- Fix warnings for the new elixir version 1.13

## [1.6.X] 2020-01-20

- Update type names and docs for consistent naming convention (Note: there is no logic or method name change)
- Update the Travis script to prevent breaks on merges:
- - Include dialyzer warnings
- - Include coverage
- - Include credo checks
- Update `EventBus.Model.Event` struct optional attribute type specs to allow `nil` values
- Update license year
- Change `EventBus.Service.Store.fetch` to return a safe value when ETS data is missing and log it

## [1.5.X] 2018.09.27

- Fix Elixir `v1.7.x` warnings for string to atom conversions
- Remove deprecated `EventBus.Util.String` module
- Move the time calculation logic into the new `MonotonicTime` utility module
- Set `initialized_at` value on `EventSource` helper to a monotonically increasing time
- Enhance tests for the `:second` time unit
- Enhance tests for the `unique_id` generator

## [1.4.X] 2018.09.07

- Add public types to main module to increase type safety and readability
- Remove allowence of passing string on topic registration/deregistration
- Allow passing `event_shadow` to `mark_as_completed/1` and `mark_as_skipped/1`
- Update wrong spec for unsubscribe/1
- Add more test for unsubscribe/1
- Add questions section
- Change default `@eb_tme_unit` to `:microsecond`
- Change all instances of `micro_seconds` and `microseconds` to `microsecond`, as per Erlang 19+
- Fix dialyzer warnings
- Update the id generator source in test configuration

## [1.3.X] 2018.08.04

- Set default transaction to the id
- Delegate optional variables to optional library configuration when building/notifying events with Event builder
- Add random id generator for Event builder
- Introduce `fetch_event_data` function to fetch only event data
- Log empty topic subscribers
- Add missing tests for existence check
- Update time spent calculation for EventSource block
- Remove support for system event tracing (Update the wiki to create wrapper for system event tracing)
- Dialyzer enhancements
- Test and documentation enhancements

## [1.2.X] - 2018.02.24

- Remove support for system event tracing for `notify` action (unnecessary)
- Move internal modules under managers namespace for better documentation
- Add `subscribed?` function to check subscriptions

## [1.1.X] - 2018.02.21

- Optional system events which notify the `eb_action_called` topic for the actions: `notify`, `register_topic`, `unregister_topic`, `subscribe`, `unsubscribe`, `mark_as_completed`, `mark_as_skipped`
- Add public exist? function to Topic, Watcher, and Store
- Check existence of topic in a blocking manner
- Register/Unregister topic in a blocking manner

## [1.0.0] - 2018.01.23

- Move build and notify blocks into EventSource
- Add use keyword for Source for developer friendly require and aliases
- Split GenServers and Services
- Move utility functions into its own module
- Add addons section to README
- Switch to microseconds when auto event structuring with `EventSource` to increase compability with Zipkin and Datadog APM
- Error topic introduced for dynamic event builder/notifier with `EventSource`. Now you can pass `:error_topic` key, EvetSource automatically check the result of execution block for `{:error, _}` tuple and create an event structure for the given `:error_topic`.
- Add elixir formatter config to format code

## [0.9.0] - 2018.01.06

- Add `source` attribute to increase traceability
- Add optional configuration to Subscriber to use the same module/function with different configurations to process the event. The aim of this change is increasing re-useability of the subscriber with several configurations. For example, this will allow writing an HTTP consumer or an AWS lambda caller function with different configurations.

## [0.8.0] - 2018.01.06

- Register/unregister topics on-demand (`EventBus.register_topic/1` and `EventBus.unregister/1`)
- Add block/yield builder for Event with auto `initialized_at` and `occurred_at` attribute assignments
- Add block/yield notifier for delivering/notifying events creation with same benefits of build block
- Add changelog file

## [0.7.0] - 2018.01.06

- Add `initialized_at` attribute