Member-only story
RxJS & Angular: Declarative If / Else
Source Code: Github 🚀 | Live Examples & Snippets 🚀
Article Goal 🎯
Leveraging the RxJS Filter Operator. Use a consistent declarative programming paradigm, to potentially improve code clarity and readability.
Key Concepts 📝
- Control Flow: is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated
- Choice: perform different computations or actions depending on whether a programmer-specified boolean condition evaluates to true or false.
- Declarative Programming: is a programming paradigm — a style of building the structure and elements of computer programs — that expresses the logic of a computation without describing its control flow
- Reactive Programming: is a declarative programming paradigm concerned with data streams and the propagation of change — RxJS is a Library for Reactive Programming (Thus RxJS is a Declarative Paradigm)
- RxJS Filter Operator: Filter items emitted by the source Observable by only emitting those that satisfy a specified predicate.
Explanation & Summary 🧪
Emphasis on explicit control flow is what differentiates imperative programming from declarative programming.
We can (and most of us, myself included, probably do) mix RxJS with imperative programming. Writing conditional statements (if / else) like this:
Using streams (Observables), composition (merge), and the filter operator. We can create the same result without writing if / else.
💡 Note: Imperative programming is not bad or an anti-pattern. — This is simply another way of achieving the same result.
