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[英]Angular 2, How to Share Array Data Between components using service?
[英]How to share service data between components correctly in Angular 2
我想創建一個從.json文件中獲取數據一次並將其共享給多個訂閱者的服務。 但是現在,根據我的解決方案,從.json文件獲取數據的請求數量等於我的服務的子服務數量。
getconfig.service.ts
import {Injectable} from 'angular2/core'; import {Http, Response} from "angular2/http"; @Injectable() export class ConfigService { config: any; http: Http; constructor(http: Http) { this.http = http; console.log('Inside service'); this.config = this.http.get('/config.json'); } }
robotui.component.ts
... import {ConnectionService} from '../services/connection.service'; @Component({ ... providers: [HTTP_PROVIDERS, ConfigService, ConnectionService] ... }) constructor(private _configService: ConfigService) { this._configService.config.subscribe((observer) => { console.log('Subscribe in RobotUI component', JSON.parse(observer._body)); }); }
實際照片組件
import {Component} from 'angular2/core'; import {ConfigService} from '../services/getconfig.service'; @Component({ ... providers: [ConfigService] }) export class ActualPhotoComponent { constructor(private _configService: ConfigService) { this._configService.config.subscribe((observer) => { console.log('Subscribe in ActualPhoto component', JSON.parse(observer._body)); }); } }
當我在控制台中運行它時,我看到:
因此,每個子域都有一個get請求。 我只需要一次獲取config.json文件,將此信息保存在服務中並與多個子服務共享時,就需要一個解決方案。
那是因為
@Component({
...
providers: [ConfigService] //<--- this creates service instance per component
})
要在控制器/組件之間共享數據並僅創建單個實例,您必須將服務注入bootstrap function
。
import {ConfigService } from './path to service';
bootstrap('AppCompoent',[configService]) //<----Inject here it will create a single instance only
在訂閱組件中,
robotui.component.ts
...
import {ConfigService} from '../services/getconfig.service'; //<----- Note this line here....
import {ConnectionService} from '../services/connection.service';
@Component({
...
... // No providers needed anymore
...
})
constructor(private _configService: ConfigService) {
this._configService.config.subscribe((observer) => {
console.log('Subscribe in RobotUI component', JSON.parse(observer._body));
});
}
實際照片組件
import {Component} from 'angular2/core';
import {ConfigService} from '../services/getconfig.service';
@Component({
...
... // No providers needed anymore...
})
export class ActualPhotoComponent {
constructor(private _configService: ConfigService) {
this._configService.config.subscribe((observer) => {
console.log('Subscribe in ActualPhoto component', JSON.parse(observer._body));
});
}
}
這是您應該做的。
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