## Inheritance Semantics:
Decorators:
1) list the decorators of the class and its parents in the ancestor first order
2) only use the last decorator of each kind (e.g. @Component / ...)
Constructor parameters:
If a class inherits from a parent class and does not declare
a constructor, it inherits the parent class constructor,
and with it the parameter metadata of that parent class.
Lifecycle hooks:
Follow the normal class inheritance model,
i.e. lifecycle hooks of parent classes will be called
even if the method is not overwritten in the child class.
## Example
E.g. the following is a valid use of inheritance and it will
also inherit all metadata:
```
@Directive({selector: 'someDir'})
class ParentDirective {
constructor(someDep: SomeDep) {}
ngOnInit() {}
}
class ChildDirective extends ParentDirective {}
```
Closes#11606Closes#12892
This is needed to resolve symbols without `.d.ts` files.
This bumps the version of the metadata from 1 to 2.
This adds logic into `ng_host.ts` to automatically upgrade
version 1 to version 2 metadata by adding the exported symbols
from the `.d.ts` file.
Add support for the `$postDigest()` and `$onDestroy()` lifecycle hooks.
Better align the behavior of the `$onChanges()` and `$onInit()` lifecycle hooks
with Angular 1.x:
- Call `$onInit()` before pre-linking.
- Always instantiate the controller before calling `$onChanges()`.
Add upgrade-static.umd.js bundles
This allows depending on it without getting a transitive dependency on compiler.
BREAKING CHANGE:
Four newly added APIs in 2.2.0-beta:
downgradeComponent, downgradeInjectable, UpgradeComponent, and UpgradeModule
are no longer exported by @angular/upgrade.
Import these from @angular/upgrade/static instead.
This commit introduces a new API to the ngUpgrade module, which is compatible
with AoT compilation. Primarily, it removes the dependency on reflection
over the Angular 2 metadata by introducing an API where this information
is explicitly defined, in the source code, in a way that is not lost through
AoT compilation.
This commit is a collaboration between @mhevery (who provided the original
design of the API); @gkalpak & @petebacondarwin (who implemented the
API and migrated the specs from the original ngUpgrade tests) and @alexeagle
(who provided input and review).
This commit is an starting point, there is still work to be done:
* add more documentation
* validate the API via internal projects
* align the ngUpgrade compilation of A1 directives closer to the real A1
compiler
* add more unit tests
* consider support for async `templateUrl` A1 upgraded components
Closes#12239
Dzmitry Shylovich
Victor Berchet
Jónatan Núñez
Alex Rickabaugh
Bowen Ni
Victor Savkin
vsavkin
Tobias Bosch
Pawel Kozlowski
Bowen Ni
Alex Eagle
Chuck Jazdzewski
Peter Bacon Darwin
Matias Niemelä
Joao Dias
João Dias
Georgios Kalpakas
Thomas Shafer
Jeremy Elbourn