To prepare for pending ngForOf work, the dep from instructions -> query
should be broken. This will enable a dep from di -> instructions while
avoiding a di -> instructions -> query -> di cycle.
Analyzing this cycle also uncovered another problem: the implementation
of query() breaks tree-shaking through a hard dependency on DI concepts
of TemplateRef, ElementRef, ViewContainerRef. This is fundamentally due
to how query() can query for those values without any configuration.
Instead, this fix introduces the concept by employing the strategy
pattern, and redefining QueryReadType to pass a function which will
return one of the above values. This strategy is then used for 'read'
instead of an enum in cases where special values should be read from
the DI system.
PR Close#21430
This change makes the code cleaner for the user. It does mean
a little bit more work for us since we have to patch the `type` back
into the `DirectiveDef`. However since the patching happens only once
on startup it should not be significant.
PR Close#21374
This PR fixes a circular dependency among those files in Renderer3:
`query` -> `di` -> `instructions` -> `query` -> ...
Looking at the above dependencies the `di` -> `instructions` import is
a problematic one. Previously `di` had an import from `instructions`
since we can known about "current node" only in `instructions`
(and we need "current node" to create node injector instances).
This commit refactors the code in the way that functions in the
`di` file don't depend on any info stored module-global variables
in `instructions`.
PR Close#20855
