Grasping this concept is essential! Many resources online may be inaccurate.
Compact yet dense explanation.
🏆 Here are 4 Laws of Observables 🏆
Law 1
• Every Observable is lazy—this holds universally, with no exceptions.
Law 2
• Observables fall into two categories: cold ones, which provide a distinct execution context per subscription, operating unicast.
• Or hot ones, which share a single execution context across multiple subscribers, operating multicast.
Law 3
• A Subject acts as both an Observable and an Observer.
• The Observable side is multicast, yet it remains lazy, executing only upon the arrival of the first subscriber.
• The Observer side is eagerly instantiated, enabling the use of .next() to push data through the Subject;
• The Observer side does not signal that the Observable's execution context is active prior to the initial subscription.
Law 4
• Some Subjects maintain state, such as BehaviorSubject or ReplySubject, by expanding the Observer role.
• They incorporate capabilities to store 1..n previous states, which the Observable part then multicasts to prospective subscribers.
Does this make you consider RxJS a challenging topic (pun intended :D)?
The Angular Team has hinted at potentially making RxJS non-mandatory in the future.
Should RxJS remain a requirement?
Or is making it optional the right call?