Currently the static-query migration ignores queries declared on getters
or setters as these are not part of a `PropertyDeclaration`. We need to
handle these queries in order to cover all queries within a given project.
The usage strategy is not able to detect timing for queries on accessors,
so we add a TODO and print a message. The template strategy is able
to detect the proper timing for such queries because it's not dependent
on detecting the usage of the query.
Resolves FW-1215
PR Close#30327
Currently when someone has a call expression within the `ngOnInit` call
and we try to peek into that function with respect to the current function
context, the schematic errors because a call expression argument is
undefined. This is valid because the target function declaration defines
that parameter with a default value. In order to fix this, we need to
respect parameter default values.
PR Close#30269
Currently we always prompt when the static-query migration runs. This is not
always needed because some applications do not even use `ViewChild` or
`ContentChild` queries and it just causes confusion if developers need to
decide on a migration strategy while there is nothing to migrate.
In order to avoid this confusion, we no longer prompt for a strategy
if there are no queries declared within the project.
PR Close#30254
Introduces a new strategy for the `static-query` schematic that
is enabled by default. In order to provide a migration that works
for the most Angular applications and makes the upgrade as easy
as possible, the template strategy leverages the view engine
Angular compiler logic in order to determine the query timing
that is currently used within applications using view engine.
PR Close#29815
In order to support multiple strategies for detecting the query timing, the
query usage logic has been moved into a query usage strategy.
PR Close#29815
Queries can technically be also accessed within component templates
e.g.
```html
<my-comp [binding]="myQuery"></my-comp>
```
In that case the query with the property "myQuery" is accessed
statically and needs to be marked with `static: true`. There are
other edge cases that need to be handled as the template property
read doesn't necessarily resolve to the actual query property.
For example:
```html
<foo #myQuery></foo>
<my-comp [binding]="myQuery"></my-comp>
```
In this scenario the binding doesn't refer to the actual query
because the template reference variable takes precedence. The
query doesn't need to be marked with "static: true" this time.
This commit ensures that the `static-query` migration schematic
now handles this cases properly. Also template property reads
that access queries from within a `<ng-template>` are ignored
as these can't access the query before the view has been initialized.
Resolves FW-1216
PR Close#29713
Queries can not only be accessed within derived classes, but also in
the super class through abstract methods. e.g.
```
abstract class BaseClass {
abstract getEmbeddedForm(): NgForm {}
ngOnInit() {
this.getEmbeddedForm().doSomething();
}
}
class Subclass extends BaseClass {
@ViewChild(NgForm) form: NgForm;
getEmbeddedForm() { return this.form; }
}
```
Same applies for abstract properties which are implemented in the base class
through accessors. This case is also now handled by the schematic.
Resolves FW-1213
PR Close#29688
Currently the static-query schematic is not able to properly handle
call expressions that pass function declarations that access a given
query. e.g.
```ts
ngOnInit() {
this._callFunction(() => this.myQuery.doSomething());
}
_callFunction(cb: any) { cb(); }
```
In that case the passed function is executed synchronously in
the "ngOnInit" lifecycle and therefore the query needs to be
detected as "static".
We can fix this by keeping track of the current function context
and using it to resolve identifiers to the passed arguments.
PR Close#29663
Currently we only check getters for property access expressions. This is wrong
because property access expressions do not always cause the "getter" to be
triggered. e.g.
```ts
set a() {...}
get a() {...}
ngOnInit() {
this.a = true;
}
```
In that case the schematic currently incorrectly checks the "getter", while this is a binary
expression and the property access is used as left-side of the binary expression. In that
case we need to check the setter declaration of the property and not the "getter". In order
to fix this, we need to also check `ts.BinaryExpression` nodes and check getters/setters
based on the used operator token. There are three types of binary expressions:
1) Value assignment (using `=`). In that case only the setter is triggered.
2) Compound assignment (e.g. using `+=`). In that case `getter` and `setter` are triggered.
3) Comparison (e.g. using `===`). In that case only the getter is triggered.
PR Close#29663
Queries can also be statically accessed within getters. e.g.
```ts
ngOnInit() {
this.myQueryGetter.doSomething();
}
```
In that case we need to check if the `myQueryGetter` definition accesses
a query statically. As we need to use the type checker for every property acess
within lifecylce hooks, the schematic might become slower than before, but considering
that this is a one-time execution, it is totally fine using the type-checker extensively.
PR Close#29609
Queries can be also used statically within the "ngDoCheck" and "ngOnChanges" lifecylce hook.
In order to properly detect all queries, we need to also respect these lifecycle hooks.
Resolves FW-1192
PR Close#29492
Currently the static-query migration does not properly handle functions which
are declared externally. This is because we don't resolve the symbol of the
call-expression through its type. Currently we just determine the symbol of the
call-expression through the given call expression node, which doesn't necessarily
refer to the *value declaration* of the call expression. e.g. the symbol refers to the
import declaration which imports the external function. This means that we currently
can't check the external function as we couldn't find the actual value declaration.
We can fix this by resolving the type of the call expression and using the type in order
to retrieve the symbol containing the *value declaration*
PR Close#29133
With 6215799055, we introduced a schematic
for the Angular core package that automatically migrates unexplicit
query definitions to the explicit query timing (static <-> dynamic).
As the initial foundation was already big enough, it was planned
to come up with a follow-up that handles asynchronous query
usages properly. e.g. queries could be used in Promises,
`setTimeout`, `setInterval`, `requestAnimationFrame` and more, but
the schematic would incorrectly declare these queries as static.
This commit ensures that we properly handle these micro/macro
tasks and don't incorrectly consider queries as static.
The declaration usage visitor should only check the synchronous
control flow and completely ignore any statements within function
like expressions which aren't explicitly executed in a synchronous
way. e.g. IIFE's still work as the function expression is
synchronously invoked.
PR Close#29133
Introduces an update schematic for the "@angular/core" package
that automatically migrates pre-V8 "ViewChild" and "ContentChild"
queries to the new explicit timing syntax. This is not required
yet, but with Ivy, queries will be "dynamic" by default. Therefore
specifying an explicit query timing ensures that developers can
smoothly migrate to Ivy (once it's the default).
Read more about the explicit timing API here:
https://github.com/angular/angular/pull/28810
PR Close#28983
Paul Gschwendtner