This is necessary to enable type-based optimizations with Closure.
Without explicity making these options the same named type, Closure
thinks they are different types and cannot disambiguate the `fromObject`
property.
Today, constructing a new GET request with headers looks like:
const headers = new HttpHeaders({
'My-Header': 'header value',
});
http.get('/url', {headers}).subscribe(...);
This indirection is unnecessary. It'd be more ergonomic to write:
http.get('/url', {headers: {'My-Header': 'header value'}}).subscribe(...);
This commit allows that new syntax, both for HttpHeaders and HttpParams.
In the HttpParams case it also allows construction of HttpParams with a map.
PR Close#18490
HttpClient is an evolution of the existing Angular HTTP API, which exists
alongside of it in a separate package, @angular/common/http. This structure
ensures that existing codebases can slowly migrate to the new API.
The new API improves significantly on the ergonomics and features of the legacy
API. A partial list of new features includes:
* Typed, synchronous response body access, including support for JSON body types
* JSON is an assumed default and no longer needs to be explicitly parsed
* Interceptors allow middleware logic to be inserted into the pipeline
* Immutable request/response objects
* Progress events for both request upload and response download
* Post-request verification & flush based testing framework
Jeremy Elbourn
Alex Rickabaugh