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
Improves the failure messages for the `template-var-assignment` schematic. After manual
testing of the schematic it's not quite clear for developers what the failure message means
without any context. The schematic now also references a short markdown file mentioning
what needs to be changed, but eventually this document needs to be expanded with more
information and context of the reasoning behind this change within Ivy.
PR Close#29708
Introduces a new update schematic called "template-var-assignment"
that is responsible for analyzing template files in order to warn
developers if template variables are assigned to values.
The schematic also comes with a driver for `tslint` so that the
check can be used wtihin Google.
PR Close#29608
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
Fixes the incorrect failure message or the TSLint rule that
is used within Google. The TSLint rule is not part of the
public schematic code.
Additionally in order to make it easier to understand what
action the developer needs to take, we rather print out the
expected "static: true/false" statement instead of saying that
a query needs to be static or dynamic. Dynamic is ambiguous, as
there is no `dynamic: true` option.
PR Close#29320
Improves the failure message for the `explicit-query` timing TSLint rule
that is used within Google. Currently it's not very clear what action
developers need to take in order to resolve the lint failure manually.
PR Close#29258
In order to be able to use the static-query migration logic within
Google, we need to provide a TSLint rule entry-point that wires up
the schematic logic and provides reporting and automatic fixes.
PR Close#29258
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
Currently when the static-query runs for a project with multiple TypeScript
configuration files (e.g. a usual CLI project), the migration incorrectly
applies the code transformation multiple times. This is because the migration
is currently based on the source file contents in the file system, while the
actual source file contents could have already changed in the devkit schematic
tree.
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
Bowen Ni