Component Hooks and Observers in Bevy 0.14

Component Hooks and Observers are two new ways of handling events in Bevy 0.14. Hooks are great for upholding invariants while Observers let you schedule systems on-demand in a wide variety of ways.

Announcement: https://bevyengine.org/news/bevy-0-14...

All examples shown in the video are in this github repo: https://github.com/rust-adventure/yt-...

Chapters

00:00 Component Hooks and Observers
00:20 tldr; one sentence
00:50 01_hooks
01:03 What are Component Hooks?
03:08 Do hooks run immediately?
03:33 02_hooks_values
04:29 hooks are for invariants
05:49 relevant docs
06:19 03_observers
06:52 hooks vs observers
07:18 defining an observer
08:09 04_observers_hooks_ordering
09:17 05_observing_entities
10:07 06_observing_entities_custom_events
10:48 commands.trigger_targets
11:40 07_observers_global
11:48 commands.trigger
12:35 Entity::PLACEHOLDER
14:00 observers as commands
14:42 08_observers_recursive
17:15 you can stack overflow
17:39 core wrap up
18:29 observers vs eventreader systems
19:38 the future of observers is today
20:22 on_replace
20:55 Observer Event Bubbling
24:34 final thoughts on observers