HTTP.get請求在從localstorage獲取值時不返回元素

Question

我目前正在完成一個項目，但我有一個小問題。

我在本地存儲一個值（它正在工作）。 我想在我的提供程序中檢索這個值，我可以檢索它，但是我不能在this.http.get函數中使用它。

我希望能夠用存儲的值調用this.http.get。

我的賽道，services.ts這是不工作：

import {Injectable} from '@angular/core'; 
import {Http} from '@angular/http'; 
import {Storage} from '@ionic/storage'; 
import 'rxjs/add/operator/map'; 
import {resolveId} from "@ionic/app-scripts/dist/rollup/ionic-rollup-resolver-plugin"; 

/* 
Generated class for the CoursService provider. 

See https://angular.io/docs/ts/latest/guide/dependency-injection.html 
for more info on providers and Angular 2 DI. 
*/ 
@Injectable() 
export class CoursService { 
    data: any; 
    identifiant: string; 

    constructor(public http: Http, private storage: Storage) { 
    console.log('Hello CoursService Provider'); 
    this.storage = storage; 
    } 

    getName() { 

    }; 

    load() { 
    if (this.data) { 
     // already loaded data 
     return Promise.resolve(this.data); 
    } 
    // don't have the data yet 
    return new Promise(resolve => { 
     // We're using Angular HTTP provider to request the data, 
     // then on the response, it'll map the JSON data to a parsed JS object. 
     // Next, we process the data and resolve the promise with the new data. 

     this.storage.get('identifiant').then((identifiant) => { 
     this.identifiant = identifiant 
     }) 

     this.http.get('https://api.corentincloss.fr/intranet/edt.php?id=' + this.identifiant) 
     .map(res => res.json()) 
     .subscribe(data => { 
      // we've got back the raw data, now generate the core schedule data 
      // and save the data for later reference 
      this.data = data; 
      resolve(this.data); 
     }); 
    }); 
    } 

} 

，其中數據是空返回此對象：

現在我的賽道服務。 ts這是工作時，我手動定義this.identifiant：

import {Injectable} from '@angular/core'; 
import {Http} from '@angular/http'; 
import {Storage} from '@ionic/storage'; 
import 'rxjs/add/operator/map'; 
import {resolveId} from "@ionic/app-scripts/dist/rollup/ionic-rollup-resolver-plugin"; 

/* 
Generated class for the CoursService provider. 

See https://angular.io/docs/ts/latest/guide/dependency-injection.html 
for more info on providers and Angular 2 DI. 
*/ 
@Injectable() 
export class CoursService { 
    data: any; 
    identifiant: string; 

    constructor(public http: Http, private storage: Storage) { 
    console.log('Hello CoursService Provider'); 
    this.storage = storage; 
    } 

    getName() { 

    }; 

    load() { 
    if (this.data) { 
     // already loaded data 
     return Promise.resolve(this.data); 
    } 
    // don't have the data yet 
    return new Promise(resolve => { 
     // We're using Angular HTTP provider to request the data, 
     // then on the response, it'll map the JSON data to a parsed JS object. 
     // Next, we process the data and resolve the promise with the new data. 

     /*this.storage.get('identifiant').then((identifiant) => { 
     this.identifiant = identifiant 
     })*/ 

     this.identifiant = 'closs006' 

     this.http.get('https://api.corentincloss.fr/intranet/edt.php?id=' + this.identifiant) 
     .map(res => res.json()) 
     .subscribe(data => { 
      // we've got back the raw data, now generate the core schedule data 
      // and save the data for later reference 
      this.data = data; 
      resolve(this.data); 
     }); 
    }); 
    } 

} 

返回此對象，其中數據包含的東西：

因爲像2也許3小時我在尋找，我沒有找到怎麼辦......

謝謝你的回答:)

Answer 1

因爲你知道this.storage.get是一種異步方式，你不會得到你想要的東西diately。所以你必須將http.get移動到this.storage.get().then()。

this.storage.get('identifiant').then((identifiant) => { 
    this.identifiant = identifiant 

    this.http.get('https://api.corentincloss.fr/intranet/edt.php?id=' + this.identifiant) 
     .map(res => res.json()) 
     .subscribe(data => { 
      // we've got back the raw data, now generate the core schedule data 
      // and save the data for later reference 
      this.data = data; 
      resolve(this.data); 
     }); 
    })