[英]Why Angular 2+ structural directive doesn't update the view?
在我的應用程序中,我有一個具有權限數組的帳戶服務,因此我創建了一個結構指令來決定是否顯示操作的按鈕,但問題是當我登錄/注銷並更新權限數組時,該指令沒有t 更新視圖。
這是代碼:
import { Directive, Input, TemplateRef, ViewContainerRef } from '@angular/core';
import { Account } from './models';
import { AccountService } from './account.service';
@Directive({
selector: '[appAuth]',
})
export class AuthDirective {
@Input() set appAuth(action: string) {
if (this._account.permissions.includes(action)) {
this._contRef.createEmbeddedView(this._tmplRef);
} else {
this._contRef.clear();
}
}
constructor(
private _contRef: ViewContainerRef,
private _tmplRef: TemplateRef<any>,
private _account: AccountService
) { }
}
以下是該指令的使用示例:
<button
class="btn btn-default"
*appAuth="'find-accounts'"
(click)="doSomething()">
Find Accounts
</button>
import { Account, AccountService } from '../common';
import { Subscription } from 'rxjs/Subscription';
import {
Directive, Input, TemplateRef, ViewContainerRef, OnInit, OnDestroy
} from '@angular/core';
@Directive({
selector: '[appAuth]',
})
export class AuthDirective implements OnInit, OnDestroy {
private _accountChangesSubscription: Subscription;
@Input('appAuth') private appAuth: string;
constructor(
private _contRef: ViewContainerRef,
private _tmplRef: TemplateRef<any>,
private _account: AccountService
) { }
ngOnInit() {
this._accountChangesSubscription = this._account.changes$
.subscribe((account: Account) => {
const permissions = this._account.permissions;
if (permissions && permissions.includes(this.appAuth)) {
this._contRef.createEmbeddedView(this._tmplRef);
} else {
this._contRef.clear();
}
});
}
ngOnDestroy() {
this._accountChangesSubscription.unsubscribe();
}
}
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