How exactly Angular flows between Client and Server? - angular-ui-router

Question

I was exploring about Angular 8 Recently and I am new to this technology. Here is what I understood..
You build your spring rest API project, and deploy that .war file on the web server (Like tomcat)
You build your Angular client application
.ts files will be translated to equivalent .js files
The build process create a 'dist' folder. The dist folder will have .js and .html files with angular tags and directives.
You deploy dist folder on a server where node.js is installed
You go to browser and ask for index.html file
Server sends all the files in the 'dist' folder to the client, up on initial request. We now have entire client app in the browser
For all the subsequent requests, the client app will make a webservcie call to spring app through Ajax requests
Javascript will use DOM to update the part of the page with new data.
For all this to work, browser must support angular directives and must also know how to render custom components
Please help me understand!

Answer 1

Via HttpCLient
Most front-end applications communicate with backend services over the
HTTP protocol. Modern browsers support two different APIs for making
HTTP requests: the XMLHttpRequest interface and the fetch() API.
The HttpClient in #angular/common/http offers a simplified client HTTP
API for Angular applications that rests on the XMLHttpRequest interface exposed by browsers.
In the example below, we are creating a post call, params for this post are the posted object, the url, and httpOptions(Headers, httpParms etc ...)
addHero (hero: Hero): Observable<Hero> {
return this.http.post<Hero>(this.heroesUrl, hero, httpOptions)
.pipe(
catchError(this.handleError('addHero', hero))
);
}
addHero (hero: Hero): Observable<Hero> {
return this.http.post<Hero>(this.heroesUrl, hero, httpOptions)
.pipe(
catchError(this.handleError('addHero', hero))
);
}
Just like when you post from Postman, you should configure your call with the right parameters.
You call should be in a Service that will be injected in application, module, or component.