A long-requested feature for HttpClient is the ability to store and retrieve
custom metadata for requests, especially in interceptors. This commit
implements this functionality via a new context object for requests.
Each outgoing HttpRequest now has an associated "context", an instance of
the HttpContext class. An HttpContext can be provided when making a request,
or if not then an empty context is created for the new request. This context
shares its lifecycle with the entire request, even across operations that
change the identity of the HttpRequest instance such as RxJS retries.
The HttpContext functions as an expando. Users can create typed tokens as instances of HttpContextToken, and
read/write a value for the key from any HttpContext object.
This commit implements the HttpContext functionality. A followup commit will
add angular.io documentation.
PR Close#25751
They aim to improve code readability.
Since they are defined by `const enum` they have zero runtime performance impact
over just using constant literals.
Fixes#23543
PR Close#23548
The `HttpParamsOptions` was not documented or included in the public API even
though it is a constructor argument of `HttpParams` which is a part of the
public API. This commit adds the `HttpParamsOptions` into the exports, thus
making it a part of the public API.
Resolves#20276
PR Close#35829
Fixes#23023.
When a HTTP Interceptor injects HttpClient it causes a DI cycle. This fix is to use Injector to lazily inject HTTP_INTERCEPTORS while setting up the HttpHandler on the server so as to break the cycle.
PR Close#24229
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