g-marcin-journal

  fig 1.1 BehaviorSubject abstraction marble diagram       It is high time to write another part of angular basics revision. Last time i mentioned Subject object. It is also worth to describe other ‚special’ cases of Subject. The first is behavior subject. It is part of powerful tool for reactive programming called rxjs . When writing angular version of exchange app or mars-rover-photos app I was using behavior subject in following way. Start with declaring behavioral subject private field within your service. The following example ilustrates this step: private myDataSubject: BehaviorSubject<any> = new BehaviorSubject<any>( null );     it will declare new private field with myDataSubject name and BehaviorSubject type. The value within <> braces is called type parameter and is a part of TypeScript generic types. In this case it would describe the type of values emited by this subject. on the right side of the assignment statement we can see basic javas

fig 1.1 angular application structure overview      Recently I have been re-writing one of my side projects using another js framework. Originaly written in react, after several days and long hours of scrolling and prompting it was re-shaped to Angular version . In this blog post I want to summarize the stuff I have learned about javascript frontend framework developed by Google . There are only class components. No function component nor hooks available in angular. Moreover it requires developer to use typescript straightaway without support for vanillla js which make it less available for beginners. Angular has no dedicated syntax such as jsx/tsx which enables to combine template, controller and styles within single file. It divides the responsibilities to separate view-template.html file and component.ts file which contains logic. It is a good moment to mention that re-renders of the ui uses diferent technique under the hood. Angular utilizes incremental DOM mechanism a