For URLs that use auxiliary route outlets in the second or following path segments,
when removing the auxiliary route segment, parenthesis remain for the primary outlet segment.
This causes the following error when trying to reload an URL: "Cannot match any route".
The commit adds a check for this scenario, serializing the URL as "a/b" instead of "a/(b)".
PR Close#24656
PR Close#37163
Partial resubmit of #26243
Fixes incorrect url tree generation for empty path components with children.
Adds a test to demonstrate the failure of createUrlTree for those routes.
Fixes#13011Fixes#35687
PR Close#37446
The Router use the type `Params` for all of:
- position parameters,
- matrix parameters,
- query parameters.
`Params` is defined as follow `type Params = {[key: string]: any}`
Because parameters can either have single or multiple values, the type should
actually be `type Params = {[key: string]: string | string[]}`.
The client code often assumes that parameters have single values, as in the
following exemple:
```
class MyComponent {
sessionId: Observable<string>;
constructor(private route: ActivatedRoute) {}
ngOnInit() {
this.sessionId = this.route
.queryParams
.map(params => params['session_id'] || 'None');
}
}
```
The problem here is that `params['session_id']` could be `string` or `string[]`
but the error is not caught at build time because of the `any` type.
Fixing the type as describe above would break the build because `sessionId`
would becomes an `Observable<string | string[]>`.
However the client code knows if it expects a single or multiple values. By
using the new `ParamMap` interface the user code can decide when it needs a
single value (calling `ParamMap.get(): string`) or multiple values (calling
`ParamMap.getAll(): string[]`).
The above exemple should be rewritten as:
```
class MyComponent {
sessionId: Observable<string>;
constructor(private route: ActivatedRoute) {}
ngOnInit() {
this.sessionId = this.route
.queryParamMap
.map(paramMap => paramMap.get('session_id') || 'None');
}
}
```
Added APIs:
- `interface ParamMap`,
- `ActivatedRoute.paramMap: ParamMap`,
- `ActivatedRoute.queryParamMap: ParamMap`,
- `ActivatedRouteSnapshot.paramMap: ParamMap`,
- `ActivatedRouteSnapshot.queryParamMap: ParamMap`,
- `UrlSegment.parameterMap: ParamMap`