The `R3TargetBinder` accepts an interface for directive metadata which
declares types for `input` and `output` objects. These types convey the
mapping between the property names for an input or output and the
corresponding property name on the component class. Due to
`R3TargetBinder`'s requirements, this mapping was specified with property
names as keys and field names as values.
However, because of duck typing, this interface was accidentally satisifed
by the opposite mapping, of field names to property names, that was produced
in other parts of the compiler. This form more naturally represents the data
model for inputs.
Rather than accept the field -> property mapping and invert it, this commit
introduces a new abstraction for such mappings which is bidirectional,
eliminating the ambiguous plain object type. This mapping uses new,
unambiguous terminology ("class property name" and "binding property name")
and can be used to satisfy both the needs of the binder as well as those of
the template type-checker (field -> property).
A new test ensures that the input/output metadata produced by the compiler
during analysis is directly compatible with the binder via this unambiguous
new interface.
PR Close#38685
Previously, bound events were incorrectly bound to directives with
inputs matching the bound event attribute. This fixes that so bound
events can only be bound to directives with matching outputs.
Adds tests for all kinds of directive matching on bound attributes.
PR Close#31938
Prior to this change, namespaced elements such as SVG elements would not
participate correctly in directive matching as their namespace was not
ignored, which was the case with the View Engine compiler. This led to
incorrect behavior at runtime and template type checking.
This commit resolved the issue by ignoring the namespace of elements and
attributes like they were in View Engine.
Fixes#32061
PR Close#33555
Previously, Template.templateAttrs was introduced to capture attribute
bindings which originated from microsyntax (e.g. bindings in *ngFor="...").
This means that a Template node can have two different structures, depending
on whether it originated from microsyntax or from a literal <ng-template>.
In the literal case, the node behaves much like an Element node, it has
attributes, inputs, and outputs which determine which directives apply.
In the microsyntax case, though, only the templateAttrs should be used
to determine which directives apply.
Previously, both the t2_binder and the TemplateDefinitionBuilder were using
the wrong set of attributes to match directives - combining the attributes,
inputs, outputs, and templateAttrs of the Template node regardless of its
origin. In the TDB's case this wasn't a problem, since the TDB collects a
global Set of directives used in the template, so it didn't matter whether
the directive was also recognized on the <ng-template>. t2_binder's API
distinguishes between directives on specific nodes, though, so it's more
sensitive to mismatching.
In particular, this showed up as an assertion failure in template type-
checking in certain cases, when a directive was accidentally matched on
a microsyntax template element and also had a binding which referenced a
variable declared in the microsyntax. This resulted in the type-checker
attempting to generate a reference to a variable that didn't exist in that
scope.
The fix is to distinguish between the two cases and select the appropriate
set of attributes to match on accordingly.
Testing strategy: tested in the t2_binder tests.
PR Close#29698
This commit introduces the "t2" API, which processes parsed template ASTs
and performs a number of functions such as binding (the process of
semantically interpreting cross-references within the template) and
directive matching. The API is modeled on TypeScript's TypeChecker API,
with oracle methods that give access to collected metadata.
This work is a prerequisite for the upcoming template type-checking
functionality, and will also become the basis for a refactored
TemplateDefinitionBuilder.
PR Close#26203
