Streams principle

FP + RP + OPP DP (Observer + Iterator) = FRP => RxJS

Everythink is a stream!

Unidirection data flow

Stream pipeline (side effects postponed after => concern the consumer)

RxJS Component

• Producer => Observable
• Consumer => Observer
• Data pipeline => Observable Operators (business logic)

Abstract the notion of time

Why Observable vs Observer?

Decoupled Business Logic from View (so side-effect) => Separation of concerns

Observable liability

• Receive push event
• Transform data
• Apply business logic
• Prepare data for consumer

Observer liability

• Interact with DOM
• Log to console
• Read/Write filesystem
• Read/Write Database

RxJS API & lifecycle

next*(error|complete)?

Implementation

            // Implementation Example
            [const subscription =] stream$.timerInSeconds()             // Producer
                .interval()                                             // pipeline
                .map(x => x.value)                                      // pipeline
                .filter(x => x % 2 === 0)                               // pipeline
                .take(10)                                               // pipeline
                .subscribe(val => console.log(val))                     // consumer