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feat(ivy): support markForCheck (#22690) 

PR Close #22690
This commit is contained in:
Kara Erickson 2018-03-09 12:45:31 -08:00
parent 0d8deb0795
commit fa451bcd19
4 changed files with 327 additions and 18 deletions
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26
packages/core/src/change_detection/change_detector_ref.ts
View File

@ -11,7 +11,11 @@
*/
export abstract class ChangeDetectorRef {
/**
* Marks all {@link ChangeDetectionStrategy#OnPush OnPush} ancestors as to be checked.
* Marks a view and all of its ancestors dirty.
*
* This can be used to ensure an {@link ChangeDetectionStrategy#OnPush OnPush} component is
* checked when it needs to be re-rendered but the two normal triggers haven't marked it
* dirty (i.e. inputs haven't changed and events haven't fired in the view).
*
* <!-- TODO: Add a link to a chapter on OnPush components -->
*
@ -39,12 +43,12 @@ export abstract class ChangeDetectorRef {
abstract markForCheck(): void;
/**
* Detaches the change detector from the change detector tree.
* Detaches the view from the change detection tree.
*
* The detached change detector will not be checked until it is reattached.
*
* This can also be used in combination with {@link ChangeDetectorRef#detectChanges detectChanges}
* to implement local change detection checks.
* Detached views will not be checked during change detection runs until they are
* re-attached, even if they are dirty. `detach` can be used in combination with
* {@link ChangeDetectorRef#detectChanges detectChanges} to implement local change
* detection checks.
*
* <!-- TODO: Add a link to a chapter on detach/reattach/local digest -->
* <!-- TODO: Add a live demo once ref.detectChanges is merged into master -->
@ -93,7 +97,7 @@ export abstract class ChangeDetectorRef {
abstract detach(): void;
/**
* Checks the change detector and its children.
* Checks the view and its children.
*
* This can also be used in combination with {@link ChangeDetectorRef#detach detach} to implement
* local change detection checks.
@ -108,8 +112,7 @@ export abstract class ChangeDetectorRef {
* we want to check and update the list every five seconds.
*
* We can do that by detaching the component's change detector and doing a local change detection
* check
* every five seconds.
* check every five seconds.
*
* See {@link ChangeDetectorRef#detach detach} for more information.
*/
@ -124,7 +127,10 @@ export abstract class ChangeDetectorRef {
abstract checkNoChanges(): void;
/**
* Reattach the change detector to the change detector tree.
* Re-attaches the view to the change detection tree.
*
* This can be used to re-attach views that were previously detached from the tree
* using {@link ChangeDetectorRef#detach detach}. Views are attached to the tree by default.
*
* <!-- TODO: Add a link to a chapter on detach/reattach/local digest -->
*

2
packages/core/src/render3/instructions.ts
View File

@ -1499,7 +1499,7 @@ export function wrapListenerWithDirtyAndDefault(
}
/** Marks current view and all ancestors dirty */
function markViewDirty(view: LView): void {
export function markViewDirty(view: LView): void {
let currentView: LView|null = view;
while (currentView.parent != null) {

162
packages/core/src/render3/view_ref.ts
View File

@ -8,7 +8,7 @@
import {EmbeddedViewRef as viewEngine_EmbeddedViewRef} from '../linker/view_ref';
import {detectChanges} from './instructions';
import {detectChanges, markViewDirty} from './instructions';
import {ComponentTemplate} from './interfaces/definition';
import {LViewNode} from './interfaces/node';
import {LView, LViewFlags} from './interfaces/view';
@ -26,14 +26,93 @@ export class ViewRef<T> implements viewEngine_EmbeddedViewRef<T> {
destroy(): void { notImplemented(); }
destroyed: boolean;
onDestroy(callback: Function) { notImplemented(); }
markForCheck(): void { notImplemented(); }
/**
* Detaches a view from the change detection tree.
* Marks a view and all of its ancestors dirty.
*
* Detached views will not be checked during change detection runs, even if the view
* is dirty. This can be used in combination with detectChanges to implement local
* change detection checks.
* It also triggers change detection by calling `scheduleTick` internally, which coalesces
* multiple `markForCheck` calls to into one change detection run.
*
* This can be used to ensure an {@link ChangeDetectionStrategy#OnPush OnPush} component is
* checked when it needs to be re-rendered but the two normal triggers haven't marked it
* dirty (i.e. inputs haven't changed and events haven't fired in the view).
*
* <!-- TODO: Add a link to a chapter on OnPush components -->
*
* ### Example ([live demo](https://stackblitz.com/edit/angular-kx7rrw))
*
* ```typescript
* @Component({
* selector: 'my-app',
* template: `Number of ticks: {{numberOfTicks}}`
* changeDetection: ChangeDetectionStrategy.OnPush,
* })
* class AppComponent {
* numberOfTicks = 0;
*
* constructor(private ref: ChangeDetectorRef) {
* setInterval(() => {
* this.numberOfTicks++;
* // the following is required, otherwise the view will not be updated
* this.ref.markForCheck();
* }, 1000);
* }
* }
* ```
*/
markForCheck(): void { markViewDirty(this._view); }
/**
* Detaches the view from the change detection tree.
*
* Detached views will not be checked during change detection runs until they are
* re-attached, even if they are dirty. `detach` can be used in combination with
* {@link ChangeDetectorRef#detectChanges detectChanges} to implement local change
* detection checks.
*
* <!-- TODO: Add a link to a chapter on detach/reattach/local digest -->
* <!-- TODO: Add a live demo once ref.detectChanges is merged into master -->
*
* ### Example
*
* The following example defines a component with a large list of readonly data.
* Imagine the data changes constantly, many times per second. For performance reasons,
* we want to check and update the list every five seconds. We can do that by detaching
* the component's change detector and doing a local check every five seconds.
*
* ```typescript
* class DataProvider {
* // in a real application the returned data will be different every time
* get data() {
* return [1,2,3,4,5];
* }
* }
*
* @Component({
* selector: 'giant-list',
* template: `
* <li *ngFor="let d of dataProvider.data">Data {{d}}</li>
* `,
* })
* class GiantList {
* constructor(private ref: ChangeDetectorRef, private dataProvider: DataProvider) {
* ref.detach();
* setInterval(() => {
* this.ref.detectChanges();
* }, 5000);
* }
* }
*
* @Component({
* selector: 'app',
* providers: [DataProvider],
* template: `
* <giant-list><giant-list>
* `,
* })
* class App {
* }
* ```
*/
detach(): void { this._view.flags &= ~LViewFlags.Attached; }
@ -41,10 +120,79 @@ export class ViewRef<T> implements viewEngine_EmbeddedViewRef<T> {
* Re-attaches a view to the change detection tree.
*
* This can be used to re-attach views that were previously detached from the tree
* using detach(). Views are attached to the tree by default.
* using {@link ChangeDetectorRef#detach detach}. Views are attached to the tree by default.
*
* <!-- TODO: Add a link to a chapter on detach/reattach/local digest -->
*
* ### Example ([live demo](https://stackblitz.com/edit/angular-ymgsxw))
*
* The following example creates a component displaying `live` data. The component will detach
* its change detector from the main change detector tree when the component's live property
* is set to false.
*
* ```typescript
* class DataProvider {
* data = 1;
*
* constructor() {
* setInterval(() => {
* this.data = this.data * 2;
* }, 500);
* }
* }
*
* @Component({
* selector: 'live-data',
* inputs: ['live'],
* template: 'Data: {{dataProvider.data}}'
* })
* class LiveData {
* constructor(private ref: ChangeDetectorRef, private dataProvider: DataProvider) {}
*
* set live(value) {
* if (value) {
* this.ref.reattach();
* } else {
* this.ref.detach();
* }
* }
* }
*
* @Component({
* selector: 'my-app',
* providers: [DataProvider],
* template: `
* Live Update: <input type="checkbox" [(ngModel)]="live">
* <live-data [live]="live"><live-data>
* `,
* })
* class AppComponent {
* live = true;
* }
* ```
*/
reattach(): void { this._view.flags |= LViewFlags.Attached; }
/**
* Checks the view and its children.
*
* This can also be used in combination with {@link ChangeDetectorRef#detach detach} to implement
* local change detection checks.
*
* <!-- TODO: Add a link to a chapter on detach/reattach/local digest -->
* <!-- TODO: Add a live demo once ref.detectChanges is merged into master -->
*
* ### Example
*
* The following example defines a component with a large list of readonly data.
* Imagine, the data changes constantly, many times per second. For performance reasons,
* we want to check and update the list every five seconds.
*
* We can do that by detaching the component's change detector and doing a local change detection
* check every five seconds.
*
* See {@link ChangeDetectorRef#detach detach} for more information.
*/
detectChanges(): void { detectChanges(this.context); }
checkNoChanges(): void { notImplemented(); }

155
packages/core/test/render3/change_detection_spec.ts
View File

@ -756,6 +756,161 @@ describe('change detection', () => {
});
describe('markForCheck()', () => {
let comp: OnPushComp;
class OnPushComp {
value = 'one';
doCheckCount = 0;
constructor(public cdr: ChangeDetectorRef) {}
ngDoCheck() { this.doCheckCount++; }
static ngComponentDef = defineComponent({
type: OnPushComp,
tag: 'on-push-comp',
factory: () => comp = new OnPushComp(injectChangeDetectorRef()),
/** {{ value }} */
template: (ctx: OnPushComp, cm: boolean) => {
if (cm) {
text(0);
}
textBinding(0, bind(ctx.value));
},
changeDetection: ChangeDetectionStrategy.OnPush
});
}
class OnPushParent {
value = 'one';
static ngComponentDef = defineComponent({
type: OnPushParent,
tag: 'on-push-parent',
factory: () => new OnPushParent(),
/**
* {{ value }} -
* <on-push-comp></on-push-comp>
*/
template: (ctx: OnPushParent, cm: boolean) => {
if (cm) {
text(0);
elementStart(1, OnPushComp);
elementEnd();
}
textBinding(0, interpolation1('', ctx.value, ' - '));
OnPushComp.ngComponentDef.h(2, 1);
directiveRefresh(2, 1);
},
changeDetection: ChangeDetectionStrategy.OnPush
});
}
it('should schedule check on OnPush components', () => {
const parent = renderComponent(OnPushParent);
expect(getRenderedText(parent)).toEqual('one - one');
comp.value = 'two';
tick(parent);
expect(getRenderedText(parent)).toEqual('one - one');
comp.cdr.markForCheck();
requestAnimationFrame.flush();
expect(getRenderedText(parent)).toEqual('one - two');
});
it('should only run change detection once with multiple calls to markForCheck', () => {
renderComponent(OnPushParent);
expect(comp.doCheckCount).toEqual(1);
comp.cdr.markForCheck();
comp.cdr.markForCheck();
comp.cdr.markForCheck();
comp.cdr.markForCheck();
comp.cdr.markForCheck();
requestAnimationFrame.flush();
expect(comp.doCheckCount).toEqual(2);
});
it('should schedule check on ancestor OnPush components', () => {
const parent = renderComponent(OnPushParent);
expect(getRenderedText(parent)).toEqual('one - one');
parent.value = 'two';
tick(parent);
expect(getRenderedText(parent)).toEqual('one - one');
comp.cdr.markForCheck();
requestAnimationFrame.flush();
expect(getRenderedText(parent)).toEqual('two - one');
});
it('should schedule check on OnPush components in embedded views', () => {
class EmbeddedViewParent {
value = 'one';
showing = true;
static ngComponentDef = defineComponent({
type: EmbeddedViewParent,
tag: 'embedded-view-parent',
factory: () => new EmbeddedViewParent(),
/**
* {{ value }} -
* % if (ctx.showing) {
* <on-push-comp></on-push-comp>
* % }
*/
template: (ctx: EmbeddedViewParent, cm: boolean) => {
if (cm) {
text(0);
container(1);
}
textBinding(0, interpolation1('', ctx.value, ' - '));
containerRefreshStart(1);
{
if (ctx.showing) {
if (embeddedViewStart(0)) {
elementStart(0, OnPushComp);
elementEnd();
}
OnPushComp.ngComponentDef.h(1, 0);
directiveRefresh(1, 0);
embeddedViewEnd();
}
}
containerRefreshEnd();
},
changeDetection: ChangeDetectionStrategy.OnPush
});
}
const parent = renderComponent(EmbeddedViewParent);
expect(getRenderedText(parent)).toEqual('one - one');
comp.value = 'two';
tick(parent);
expect(getRenderedText(parent)).toEqual('one - one');
comp.cdr.markForCheck();
requestAnimationFrame.flush();
expect(getRenderedText(parent)).toEqual('one - two');
parent.value = 'two';
tick(parent);
expect(getRenderedText(parent)).toEqual('one - two');
comp.cdr.markForCheck();
requestAnimationFrame.flush();
expect(getRenderedText(parent)).toEqual('two - two');
});
// TODO(kara): add test for dynamic views once bug fix is in
});
});
});