[英]Angular2 Injecting Service into another Service
我找不到我的錯誤。
app.module.ts
...
providers: [ValidateService,AuthService]
...
我在register.component.ts中執行以下操作:
import {AuthService} from '../../services/auth.service';
...
constructor( private _validateService: ValidateService,
private _fms: FlashMessagesService,
private _authService: AuthService,
private _router: Router
) { }
...
ngOnInit() {
this._authService.uniqueUser({username:'zomh'}).subscribe(data => {
console.log("data.success: "+data.success);
if(!data.success) { // Username already exists
console.log('exists');
}
else {
console.log('does not exist');
}
});
}
按預期工作的用戶已經在數據庫中,因此我得到一個用戶存在於控制台中。
我在validate.service.ts中幾乎做同樣的事情(將其分解為這一點):
import { AuthService } from './auth.service';
import { Injectable } from '@angular/core';
import { FormControl } from '@angular/forms';
@Injectable()
export class ValidateService {
constructor( public _authService: AuthService) { }
validateRegister(user) {
if(user.name == undefined || user.email == undefined || user.username == undefined || user.password == undefined)
return false;
else
return true;
}
validateEmailPattern(c: FormControl) {
const re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
if (re.test(c.value))
return null;
else
return {invalidPattern:true};
}
validateUsernamePattern(c: FormControl) {
const re = /^[A-Za-z0-9]+(?:[ _-][A-Za-z0-9]+)*$/
if (re.test(c.value))
return null;
else
return {invalidPattern:true};
}
validateUsernameIsUnique (c: FormControl) {
let ret:any;
if (c.value.length >= 3)
{
console.log(c.value);
this._authService.uniqueUser({username:'zomh'}).subscribe(data => {
if(!data.success) { // Username already exists
console.log('call from service: exists');
}
else {
console.log('call from service: does not exist');
}
});
}
return {usernameIsTaken:true};
}
}
但是在這里,我得到了Cannot read property _authService of undefined
異常
對我來說,該服務似乎未正確注入。 但是我找不到我的錯誤。
更新1:所以我確實將auth Service調用復制到了構造函數中並工作。 因此,必須要有一些。 相關錯誤(?)我無法從構造函數之外的任何其他方法獲取this._authService的值?
@Injectable()
export class ValidateService {
constructor( private _authService: AuthService ) {
this._authService.uniqueUser({ username: 'zomh' }).subscribe(data => {
if (!data.success) { // Username already exists
console.log('call from service: exists');
}
else {
console.log('call from service: does not exist');
}
});
}
我不認為您可以在@Injectable
和export class ValidateService {
嘗試沒有那條線。
閱讀文章后,我將方法重寫為實例方法:
validateUsernameIsUnique = (c: FormControl) => {
let ret: any;
if (c.value.length >= 3) {
this._authService.uniqueUser({ username: c.value }).subscribe(data => {
if (!data.success) { // Username already exists
console.log('call from service: exists');
}
else {
console.log('call from service: does not exist');
}
});
}
...
它解決了問題。 我仍然不確定為什么必須這樣做,請隨時添加知識
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