fix(ivy): queries should match elements inside ng-container with the descendants: false option (#35384)

Before this change content queries with the `descendants: false` option, as implemented in ivy,
would not descendinto `<ng-container>` elements. This behaviour was different from the way the
View Engine worked. This change alligns ngIvy and VE behaviours when it comes to queries and the
`<ng-container>` elements and fixes a common bugs where a query target was placed inside the
`<ng-container>` element with a * directive on it.

Before:

```html
<needs-target>
  <ng-container *ngIf="condition">
    <div #target>...</div>  <!-- this node would NOT match -->
  </ng-container>
</needs-target>
```

After:

```html
<needs-target>
  <ng-container *ngIf="condition">
    <div #target>...</div>  <!-- this node WILL match -->
  </ng-container>
</needs-target>
```

Fixes #34768

PR Close #35384
This commit is contained in:
Pawel Kozlowski 2020-02-12 14:31:51 +01:00 committed by Alex Rickabaugh
parent 5fbfe6996a
commit 3f4e02b8c7
6 changed files with 272 additions and 81 deletions

View File

@ -26,4 +26,4 @@
}
}
}
}
}

View File

@ -64,4 +64,4 @@
}
}
}
}
}

View File

@ -188,7 +188,23 @@ class TQuery_ implements TQuery {
private isApplyingToNode(tNode: TNode): boolean {
if (this._appliesToNextNode && this.metadata.descendants === false) {
return this._declarationNodeIndex === (tNode.parent ? tNode.parent.index : -1);
const declarationNodeIdx = this._declarationNodeIndex;
let parent = tNode.parent;
// Determine if a given TNode is a "direct" child of a node on which a content query was
// declared (only direct children of query's host node can match with the descendants: false
// option). There are 3 main use-case / conditions to consider here:
// - <needs-target><i #target></i></needs-target>: here <i #target> parent node is a query
// host node;
// - <needs-target><ng-template [ngIf]="true"><i #target></i></ng-template></needs-target>:
// here <i #target> parent node is null;
// - <needs-target><ng-container><i #target></i></ng-container></needs-target>: here we need
// to go past `<ng-container>` to determine <i #target> parent node (but we shouldn't traverse
// up past the query's host node!).
while (parent !== null && parent.type === TNodeType.ElementContainer &&
parent.index !== declarationNodeIdx) {
parent = parent.parent;
}
return declarationNodeIdx === (parent !== null ? parent.index : -1);
}
return this._appliesToNextNode;
}

View File

@ -690,7 +690,14 @@ describe('query logic', () => {
expect(fixture.componentInstance.contentChildren.length).toBe(0);
});
describe('descendants', () => {
describe('descendants: false (default)', () => {
/**
* A helper function to check if a given object looks like ElementRef. It is used in place of
* the `instanceof ElementRef` check since ivy returns a type that looks like ElementRef (have
* the same properties but doesn't pass the instanceof ElementRef test)
*/
function isElementRefLike(result: any): boolean { return result.nativeElement != null; }
it('should match directives on elements that used to be wrapped by a required parent in HTML parser',
() => {
@ -715,8 +722,246 @@ describe('query logic', () => {
fixture.detectChanges();
expect(cmptWithQuery.myDefs.length).toBe(1);
});
it('should match elements with local refs inside <ng-container>', () => {
@Component({selector: 'needs-target', template: ``})
class NeedsTarget {
@ContentChildren('target') targets !: QueryList<ElementRef>;
}
@Component({
selector: 'test-cmpt',
template: `
<needs-target>
<ng-container>
<tr #target></tr>
</ng-container>
</needs-target>
`,
})
class TestCmpt {
}
TestBed.configureTestingModule({declarations: [TestCmpt, NeedsTarget]});
const fixture = TestBed.createComponent(TestCmpt);
const cmptWithQuery = fixture.debugElement.children[0].injector.get(NeedsTarget);
fixture.detectChanges();
expect(cmptWithQuery.targets.length).toBe(1);
expect(isElementRefLike(cmptWithQuery.targets.first)).toBeTruthy();
});
it('should match elements with local refs inside nested <ng-container>', () => {
@Component({selector: 'needs-target', template: ``})
class NeedsTarget {
@ContentChildren('target') targets !: QueryList<ElementRef>;
}
@Component({
selector: 'test-cmpt',
template: `
<needs-target>
<ng-container>
<ng-container>
<ng-container>
<tr #target></tr>
</ng-container>
</ng-container>
</ng-container>
</needs-target>
`,
})
class TestCmpt {
}
TestBed.configureTestingModule({declarations: [TestCmpt, NeedsTarget]});
const fixture = TestBed.createComponent(TestCmpt);
const cmptWithQuery = fixture.debugElement.children[0].injector.get(NeedsTarget);
fixture.detectChanges();
expect(cmptWithQuery.targets.length).toBe(1);
expect(isElementRefLike(cmptWithQuery.targets.first)).toBeTruthy();
});
it('should match directives inside <ng-container>', () => {
@Directive({selector: '[targetDir]'})
class TargetDir {
}
@Component({selector: 'needs-target', template: ``})
class NeedsTarget {
@ContentChildren(TargetDir) targets !: QueryList<HTMLElement>;
}
@Component({
selector: 'test-cmpt',
template: `
<needs-target>
<ng-container>
<tr targetDir></tr>
</ng-container>
</needs-target>
`,
})
class TestCmpt {
}
TestBed.configureTestingModule({declarations: [TestCmpt, NeedsTarget, TargetDir]});
const fixture = TestBed.createComponent(TestCmpt);
const cmptWithQuery = fixture.debugElement.children[0].injector.get(NeedsTarget);
fixture.detectChanges();
expect(cmptWithQuery.targets.length).toBe(1);
expect(cmptWithQuery.targets.first).toBeAnInstanceOf(TargetDir);
});
it('should match directives inside nested <ng-container>', () => {
@Directive({selector: '[targetDir]'})
class TargetDir {
}
@Component({selector: 'needs-target', template: ``})
class NeedsTarget {
@ContentChildren(TargetDir) targets !: QueryList<HTMLElement>;
}
@Component({
selector: 'test-cmpt',
template: `
<needs-target>
<ng-container>
<ng-container>
<ng-container>
<tr targetDir></tr>
</ng-container>
</ng-container>
</ng-container>
</needs-target>
`,
})
class TestCmpt {
}
TestBed.configureTestingModule({declarations: [TestCmpt, NeedsTarget, TargetDir]});
const fixture = TestBed.createComponent(TestCmpt);
const cmptWithQuery = fixture.debugElement.children[0].injector.get(NeedsTarget);
fixture.detectChanges();
expect(cmptWithQuery.targets.length).toBe(1);
expect(cmptWithQuery.targets.first).toBeAnInstanceOf(TargetDir);
});
it('should cross child ng-container when query is declared on ng-container', () => {
@Directive({selector: '[targetDir]'})
class TargetDir {
}
@Directive({selector: '[needs-target]'})
class NeedsTarget {
@ContentChildren(TargetDir) targets !: QueryList<HTMLElement>;
}
@Component({
selector: 'test-cmpt',
template: `
<ng-container targetDir>
<ng-container needs-target>
<ng-container>
<tr targetDir></tr>
</ng-container>
</ng-container>
</ng-container>
`,
})
class TestCmpt {
}
TestBed.configureTestingModule({declarations: [TestCmpt, NeedsTarget, TargetDir]});
const fixture = TestBed.createComponent(TestCmpt);
const cmptWithQuery = fixture.debugElement.children[0].injector.get(NeedsTarget);
fixture.detectChanges();
expect(cmptWithQuery.targets.length).toBe(1);
expect(cmptWithQuery.targets.first).toBeAnInstanceOf(TargetDir);
});
it('should match nodes when using structural directives (*syntax) on <ng-container>', () => {
@Directive({selector: '[targetDir]'})
class TargetDir {
}
@Component({selector: 'needs-target', template: ``})
class NeedsTarget {
@ContentChildren(TargetDir) dirTargets !: QueryList<TargetDir>;
@ContentChildren('target') localRefsTargets !: QueryList<ElementRef>;
}
@Component({
selector: 'test-cmpt',
template: `
<needs-target>
<ng-container *ngIf="true">
<div targetDir></div>
<div #target></div>
</ng-container>
</needs-target>
`,
})
class TestCmpt {
}
TestBed.configureTestingModule({declarations: [TestCmpt, NeedsTarget, TargetDir]});
const fixture = TestBed.createComponent(TestCmpt);
const cmptWithQuery = fixture.debugElement.children[0].injector.get(NeedsTarget);
fixture.detectChanges();
expect(cmptWithQuery.dirTargets.length).toBe(1);
expect(cmptWithQuery.dirTargets.first).toBeAnInstanceOf(TargetDir);
expect(cmptWithQuery.localRefsTargets.length).toBe(1);
expect(isElementRefLike(cmptWithQuery.localRefsTargets.first)).toBeTruthy();
});
onlyInIvy(
'VE uses injectors hierarchy to determine if node matches, ivy uses elements as written in a template')
.it('should match directives on <ng-container> when crossing nested <ng-container>', () => {
@Directive({selector: '[targetDir]'})
class TargetDir {
}
@Component({selector: 'needs-target', template: ``})
class NeedsTarget {
@ContentChildren(TargetDir) targets !: QueryList<HTMLElement>;
}
@Component({
selector: 'test-cmpt',
template: `
<needs-target>
<ng-container>
<ng-container targetDir>
<ng-container targetDir>
<tr targetDir></tr>
</ng-container>
</ng-container>
</ng-container>
</needs-target>
`,
})
class TestCmpt {
}
TestBed.configureTestingModule({declarations: [TestCmpt, NeedsTarget, TargetDir]});
const fixture = TestBed.createComponent(TestCmpt);
const cmptWithQuery = fixture.debugElement.children[0].injector.get(NeedsTarget);
fixture.detectChanges();
expect(cmptWithQuery.targets.length).toBe(3);
});
});
describe('observable interface', () => {
it('should allow observing changes to query list', () => {

View File

@ -361,19 +361,18 @@ describe('Query API', () => {
expect(comp.children.length).toBe(1);
});
onlyInIvy(
'Shallow queries don\'t cross ng-container boundaries in ivy (ng-container is treated as a regular element')
.it('should not cross ng-container boundaries with shallow queries', () => {
const template = `<needs-content-children-shallow>
it('should not cross ng-container boundaries with shallow queries', () => {
const template = `<needs-content-children-shallow>
<ng-container>
<div #q></div>
</ng-container>
</needs-content-children-shallow>`;
const view = createTestCmpAndDetectChanges(MyComp0, template);
const view = createTestCmpAndDetectChanges(MyComp0, template);
const comp = view.debugElement.children[0].injector.get(NeedsContentChildrenShallow);
expect(comp.children.length).toBe(0);
});
const comp = view.debugElement.children[0].injector.get(NeedsContentChildrenShallow);
expect(comp.children.length).toBe(1);
});
it('should contain the first descendant content child templateRef', () => {
const template = '<needs-content-child-template-ref-app>' +

View File

@ -569,75 +569,6 @@ describe('query', () => {
expect(qList.first.nativeElement).toEqual(elToQuery);
});
/**
* BREAKING CHANGE: this tests asserts different behavior as compared to Renderer2 when it
* comes to descendants: false option and <ng-container>.
*
* Previous behavior: queries with descendants: false would descend into <ng-container>.
* New behavior: queries with descendants: false would NOT descend into <ng-container>.
*
* Reasoning: the Renderer2 behavior is inconsistent and hard to explain to users when it
* comes to descendants: false interpretation (see
* https://github.com/angular/angular/issues/14769#issuecomment-356609267) so we are changing
* it in ngIvy.
*
* In ngIvy implementation queries with the descendants: false option are interpreted as
* "don't descend" into children of a given element when looking for matches. In other words
* only direct children of a given component / directive are checked for matches. This applies
* to both regular elements (ex. <div>) and grouping elements (<ng-container>,
* <ng-template>)).
*
* Grouping elements (<ng-container>, <ng-template>) are treated as regular elements since we
* can query for <ng-container> and <ng-template>, so they behave like regular elements from
* this point of view.
*/
it('should not descend into <ng-container> when descendants: false', () => {
let elToQuery;
/**
* <ng-container>
* <div #foo></div>
* </ng-container>
* class Cmpt {
* @ViewChildren('foo') deep;
* @ViewChildren('foo', {descendants: false}) shallow;
* }
*/
const Cmpt = createComponent(
'cmpt',
function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵelementContainerStart(0);
{
ɵɵelement(1, 'div', null, 0);
elToQuery = getNativeByIndex(3, getLView());
}
ɵɵelementContainerEnd();
}
},
3, 0, [], [],
function(rf: RenderFlags, ctx: any) {
if (rf & RenderFlags.Create) {
ɵɵviewQuery(['foo'], true, ElementRef);
ɵɵviewQuery(['foo'], false, ElementRef);
}
if (rf & RenderFlags.Update) {
let tmp: any;
ɵɵqueryRefresh(tmp = ɵɵloadQuery<QueryList<any>>()) &&
(ctx.deep = tmp as QueryList<any>);
ɵɵqueryRefresh(tmp = ɵɵloadQuery<QueryList<any>>()) &&
(ctx.shallow = tmp as QueryList<any>);
}
},
[], [], undefined, [['foo', '']]);
const fixture = new ComponentFixture(Cmpt);
const deepQList = fixture.component.deep;
const shallowQList = fixture.component.shallow;
expect(deepQList.length).toBe(1);
expect(shallowQList.length).toBe(0);
});
it('should read ViewContainerRef from element nodes when explicitly asked for', () => {
/**
* <div #foo></div>