简而言之:向下滚动查看解决方案。
我有一个循环依赖,我收到了警告,但这是正确的,因为我正在管理它。问题是我有一个聊天组件,在角落里你可以选择查看他们的个人资料页面,而在他们的个人资料页面中你可以选择给他们发送消息,因此出现了循环依赖。我通过以下方式进行管理:
聊天组件
public async openProfile(): Promise<void> {
this.modalCtrl.dismiss(); //closing the chat component before opening the profile modal
const profile = await this.modalCtrl.create({
component: ProfileComponent,
});
await profile.present();
}
profile.component
public async openChat(): Promise<void> {
this.modalCtrl.dismiss(); //closing the profile component before opening the chat modal
const chat = await this.modalCtrl.create({
component: ProfileComponent,
});
await chat.present();
}
有没有更简单的方法处理这个循环依赖?
更新: 根据下面的建议,我尝试创建了一个服务。然而现在我有了一个三方依赖循环:
chat.component
private modalService: ModalService;
constructor(modalService: ModalService){
this.modalService = modalService
}
public async openProfile(): Promise<void> {
this.modalService.openProfile(this.userData);
}
profile.component
private modalService: ModalService;
constructor(modalService: ModalService){
this.modalService = modalService
}
public async openChat(): Promise<void> {
this.modalService.openChat(this.userData);
}
modal.service
import { ModalController } from '@ionic/angular';
import { Injectable } from '@angular/core';
import { ProfileComponent } from '../../components/profile/profile.component';
import { ChatComponent } from '../../components/chat/chat.component';
import { UserData } from '../../interfaces/UserData/userData.interface';
@Injectable({
providedIn: 'root',
})
export class ModalService {
private modal: ModalController;
public constructor(modal: ModalController) {
this.modal = modal;
}
public async openProfileComponent(user: UserData): Promise<void> {
this.modal.dismiss();
const profile = await this.modal.create({
component: ProfileComponent,
componentProps: {
contact: user,
},
});
await profile.present();
}
public async openChatComponent(user: UserData): Promise<void> {
this.modal.dismiss();
const chat = await this.modal.create({
component: ChatComponent,
componentProps: {
contact: user,
},
});
await chat.present();
}
public close(): void {
this.modal.dismiss();
}
}
< p > 更新 Stackblitz 在使用Ionic 4时过于不稳定,因此我无法在其中复制它,因此这里有一个要点以及相关代码。
更新2
我采纳了答案中提到的建议,但仍然收到错误信息。为此,我创建了一个名为shared.module.ts
的文件,其内容如下:
import { UserService } from './componentServices/user/user.service';
import { ModalService } from './componentServices/modal/modal.service';
import { AuthenticationSecurityService } from './componentServices/auth_security/authentication-security.service';
import { AuthGuardService } from '../_guards/auth-guard.service';
import { ApiService } from './componentServices/api/api.service';
import { ChatService } from './components/chat/socketIO/chat.service';
@NgModule({
imports: [CommonModule, ReactiveFormsModule, IonicModule.forRoot(), FormsModule, IonicModule],
declarations: [
// various components
],
exports: [
// various components and common modules
],
})
export class SharedModule {
static forRoot(): ModuleWithProviders {
return {
ngModule: SharedModule,
providers: [
UserService,
ModalService,
DashboardService,
AuthenticationSecurityService,
AuthGuardService,
ApiService,
ChatService,
],
};
}
}
app.module.ts
imports: [
SharedModule.forRoot(),
]
client:135 Circular dependency detected:
src/sharedModules/componentServices/modal/modal.service.ts -> src/sharedModules/components/profile/profile.component.ts -> src/sharedModules/componentServices/modal/modal.service.ts
client:135 Circular dependency detected:
src/sharedModules/components/chat/chat.component.ts -> src/sharedModules/components/search/search.component.ts -> src/sharedModules/components/profile/profile.component.ts -> src/sharedModules/componentServices/modal/modal.service.ts -> src/sharedModules/components/chat/chat.component.ts
client:135 Circular dependency detected:
src/sharedModules/components/profile/profile.component.ts -> src/sharedModules/componentServices/modal/modal.service.ts -> src/sharedModules/components/profile/profile.component.ts
client:135 Circular dependency detected:
src/sharedModules/components/search/search.component.ts -> src/sharedModules/components/profile/profile.component.ts -> src/sharedModules/componentServices/modal/modal.service.ts -> src/sharedModules/components/chat/chat.component.ts -> src/sharedModules/components/search/search.component.ts
解决方案
正如 @bryan60 和 @Luis 所说,必须有一个缓冲区,所以我按照他们两个都建议的发射路线来做。Bryan 给出了更多的代码样式,而 Luis 则提供了很好的职责概述。这是我重构的方式:
app.component.ts
public initializeApp(): void {
this.platform.ready().then((): void => {
this.statusBar.styleDefault();
this.splashScreen.hide();
this._subToObservables();
});
}
private _subToObservables(): void {
this.modalService.openModal$.subscribe(
async (e: ModalEmitInterface): Promise<void> => {
const { command, data } = e;
switch (command) {
case 'open-profile':
const profile = await this.modalCtrl.create({
component: ProfileComponent,
componentProps: {
contact: data,
},
});
await profile.present();
break;
case 'open-chat':
// same as above
break;
default:
break;
}
},
);
}
modalSignal.service.ts
export class ModalService {
private openModalSubject: Subject<ModalEmitInterface> = new Subject<ModalEmitInterface>();
public readonly openModal$: Observable<ModalEmitInterface> = this.openModalSubject.asObservable();
private emitPayload: ModalEmitInterface;
public openProfileComponent(user: UserData): void {
this.emitPayload = {
command: 'open-profile',
data: user,
};
this.openModalSubject.next(this.emitPayload);
}
// repeat for others
}
chat.component.html
<button (click)="openProfile(user)">click me</button>
chat.component.ts
export class ChatComponent {
public constructor(private modalSignal: ModalService){}
private openProfile(user: UserData): void {
this.modalSignal.openProfileComponent(user);
}
}
就是这样,不过您仍需确保关闭模态框,否则它们将继续叠加。