[英]need to get data from web service using Angular 4 service
我創建了一個服務,通過將特定 ID 發送到后端然后獲取有關所選 ID 的數據來幫助我從 Web 服務中提取詳細信息,我創建了一個調用該服務的函數,現在我只想知道缺少什么我的代碼。
我的服務:
import { Injectable } from '@angular/core';
import { HttpClient, HttpErrorResponse, HttpParams } from
'@angular/common/http';
import { environment } from '../../environment/environment'
import { SchoolsModel } from '../models/school-model';
@Injectable()
export class GradesService {
constructor(public http: HttpClient) {
}
public getSchoolGrades(schoolId: number) {
const apiUrl: string = environment.apiBaseUrl +
'/api/en/admin/grades/division';
let promise = new Promise((resolve, reject) => {
return this.http.get(apiUrl, { params: new
HttpParams().set("school_id", schoolId.toString()) })
.subscribe(respose => {
console.log(respose.data);
return resolve(respose.data);
}, (err: HttpErrorResponse) => {
return reject(err);
});
});
return promise;
}
}
我的組件 TS:
import { Component, OnInit, ViewEncapsulation } from '@angular/core';
import { ActivatedRoute, ParamMap } from '@angular/router';
import { AuthService } from '../common-services/auth/auth.service';
import { UserService } from '../common-services/user.service';
import { Title } from '@angular/platform-browser';
import { SchoolsModel } from '../models/school-model';
import { SchoolsService } from '../business-services/schools.service';
import { GradesService } from '../business-services/grades.service';
declare const $;
@Component({
selector: 'app-divisions',
templateUrl: './divisions.component.html',
styleUrls: ['./divisions.component.css'],
encapsulation: ViewEncapsulation.Emulated
})
export class DivisionsComponent implements OnInit {
public divisionList: SchoolsModel;
constructor(
private schoolService: SchoolsService,
private gradesService: GradesService,
private titleService: Title,
private authService: AuthService,
private route: ActivatedRoute
) {}
ngOnInit(): void {
this.getSchoolGrades();
}
private getSchoolGrades(schoolId: number) {
this.gradesService.getSchoolGrades(schoolId)
.then((division: SchoolsModel) => {
// debugger;
this.divisionList = division;
}).catch(err => {
console.error("Error occured :", err)
})
}
}
我的組件 HTML
<div>
<button name="American Primary"
class="choose-list arrow-onclick1" data-toggle="collapse" data-
target="#list1">
{{divisionList.name}}<i class="fa fa-arrow-right pull-
right arrow-down-onclick1" aria-hidden="true" style="margin-top:
12px"></i>
</button>
<a routerLink="/editaisdivision"
style="text-decoration: none;"><span class="fa fa-pencil pen-pen-pen"
aria-hidden="true" style="margin-left: 10px; color: #171b5e;"></span>
</a>
</div>
學校模式:
export class SchoolsModel{
id:number;
name:string;
logo:string;
vision:string;
mission:string;
address:string;
latitude:number;
longitude:number;
district_id:number;
created_at:Date;
updated_at:Date;
}
環境:
export const environment = {
apiBaseUrl: 'https://crm.easyschools.org'
}
我想這就是您可能需要告訴我為什么組件沒有從 Web 服務捕獲正確數據並將其顯示在屏幕上的一切。
我正在嘗試盡可能具體,所以如果有不清楚的地方,請告訴我。
當您擁有像 RxJs 這樣強大的工具時,使用 promise 並不是真正的最佳解決方案,尤其是因為 Angular 使用它來處理 http 請求。 嘗試按如下方式重寫您的服務:
public getSchoolGrades(schoolId: number) {
const apiUrl: string = environment.apiBaseUrl +
'/api/en/admin/grades/division';
return this.http.get(apiUrl, { params: new HttpParams().set("school_id", schoolId.toString()) });
}
然后在您的組件中:
ngOnInit(): void {
this.getSchoolGrades(123);
}
private getSchoolGrades(schoolId: number) {
this.gradesService.getSchoolGrades(schoolId)
.catch(err => {
console.error("Error occured :", err)
})
.subscribe((division: SchoolsModel) => {
this.divisionList = division;
});
}
你的方法簽名是這樣的
getSchoolGrades(schoolId: number)
但是在 ngOnInit 中,您調用了該方法而不傳遞 schoolId
this.getSchoolGrades();
這是調用網絡服務並獲得結果的簡單方法
let token="Bearer"+" "+tokenUser;
var headers = new Headers();
headers.append('Authorization',token);
headers.append('Content-Type','application/json');
let options = new RequestOptions({ headers: headers });
this.spinnerService.show();
this.http.get('https://www.000webhost.com/sample/rest_api/api/all-user-details',options)
.subscribe((res)=> {
this.spinnerService.hide();
this.userdetails=res.json();
console.log(this.userdetails);
}
,(err) => {
this.spinnerService.hide();
console.log("Error occured");
});
}
<tbody>
<tr *ngFor = "let user of userdetails; let i=index">
<td align="left" valign="middle">{{i+1}}</td>
<td align="left" valign="middle">{{user.IPADDRESS}}</td>
<td align="left" valign="middle">{{user.INSERT}}</td>
<td align="left" valign="middle">{{user.UPDATE}}</td>
</tr>
</tbody>
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