Originally, the ivy_switch mechanism used Bazel genrules to conditionally
compile one TS file or another depending on whether ngc or ngtsc was the
selected compiler. This was done because we wanted to avoid importing
certain modules (and thus pulling them into the build) if Ivy was on or
off. This mechanism had a major drawback: ivy_switch became a bottleneck
in the import graph, as it both imports from many places in the codebase
and is imported by many modules in the codebase. This frequently resulted
in cyclic imports which caused issues both with TS and Closure compilation.
It turns out ngcc needs both code paths in the bundle to perform the switch
during its operation anyway, so import switching was later abandoned. This
means that there's no real reason why the ivy_switch mechanism needed to
operate at the Bazel level, and for the ivy_switch file to be a bottleneck.
This commit removes the Bazel-level ivy_switch mechanism, and introduces
an additional TypeScript transform in ngtsc (and the pass-through tsc
compiler used for testing JIT) to perform the same operation that ngcc
does, and flip the switch during ngtsc compilation. This allows the
ivy_switch file to be removed, and the individual switches to be located
directly next to their consumers in the codebase, greatly mitigating the
circular import issues and making the mechanism much easier to use.
As part of this commit, the tag for marking switched variables was changed
from __PRE_NGCC__ to __PRE_R3__, since it's no longer just ngcc which
flips these tags. Most variables were renamed from R3_* to SWITCH_* as well,
since they're referenced mostly in render2 code.
Test strategy: existing test coverage is more than sufficient - if this
didn't work correctly it would break the hello world and todo apps.
PR Close#26550
Create getter methods `getXXXDef` for each definition which
uses `hasOwnProperty` to verify that we don't accidently read form the
parent class.
Fixes: #24011Fixes: #25026
PR Close#25736
Various user code uses 'instanceof' to check whether a particular instance
is a TemplateRef, ElementRef, etc. Ivy needs to work with these checks.
PR Close#25775
By pulling in `compiler` into `core` the `compiler` was not
100% tree-shakable and about 8KB of code was retained
when tree-shaken with closure.
PR Close#25531
Provides a runtime and compile time switch for ivy including
`ApplicationRef.bootstrapModule`.
This is done by naming the symbols such that `ngcc` (angular
Compatibility compiler) can rename symbols in such a way that running
`ngcc` command will switch the `@angular/core` module from `legacy` to
`ivy` mode.
This is done as follows:
```
const someToken__PRE_NGCC__ = ‘legacy mode’;
const someToken__POST_NGCC__ = ‘ivy mode’;
export someSymbol = someToken__PRE_NGCC__;
```
The `ngcc` will search for any token which ends with `__PRE_NGCC__`
and replace it with `__POST_NGCC__`. This allows the `@angular/core`
package to be rewritten to ivy mode post `ngcc` execution.
PR Close#25238
When @angular/core is compiled by ngtsc, a factory file is generated
for ApplicationModule, that is currently invalid because r3_symbols
does not export NgModuleFactory. This change fixes that issue and
ensures the generated ngfactory file for @angular/core is valid.
PR Close#25392
Greg Magolan
Alex Rickabaugh
Andrew Kushnir
Matias Niemelä
Miško Hevery
Kara Erickson
Pawel Kozlowski
Ben Lesh
Marc Laval
Alex Eagle