相关疑难解决方法(0)

如何在Angular2/4/5中实现自定义异步验证器

1.它甚至得到了Angular的支持吗?看到这个开放的问题

2.如果是的话,什么是错在下面的代码

export class someClass{

    myForm:ControlGroup;

    constructor(public http:Http, public formBuilder:FormBuilder)
       this.myForm = formBuilder.group({
            ImageId: ["", Validators.required, this.asynValidator]
    });

    asyncValidator(control: Control): {[key: string]: any} {

        return new Promise (resolve => {

          let headers = new Headers();
          headers.append('Content-Type', 'application/json');

          this.http.get('http://localhost/ImageIdValidate?id='+ control.value, {headers:headers})
                .map(res => res.json())
                .subscribe(data => {
                    console.log(data);
                    if(data != null) {
                        resolve({"duplicate": true})
                    }
                    else resolve(null);      
                })
            });
        });
      }
    }
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它甚至没有提出服务器请求.

typescript angular

25
推荐指数
1
解决办法
2万
查看次数

Http在Angular 2自定义异步验证中不起作用

我正在尝试创建一个自定义异步验证器,它将转到服务器并检查电子邮件是否已注册.

不幸的是,似乎get请求永远不会被触发,因为没有任何反应.我在里面尝试了多个console.logs subscribe,但是他们没有运行.

我已经检查过该请求是否在验证器之外工作,而且确实如此,所以这不是问题所在.

import { Component } from '@angular/core';
import { FormGroup, FormBuilder, Validators, FormControl } from '@angular/forms';
import { Response, Http } from '@angular/http';

 @Component({
     templateUrl: 'build/pages/welcome/signup/signup.html',
     providers: [AuthService, CustomValidators]
})
export class Signup {

     signupForm: FormGroup;

     constructor(private formBuilder: FormBuilder, private http: Http) {

         this.signupForm = formBuilder.group({
             'email': ['', Validators.required, this.checkEmail],
         }):
     }

     checkEmail(control: FormControl): Promise<any> {

          const promise = new Promise<any>(
             (resolve, reject) => {

                 this.http.get('/sharealead/main.php?action=checkEmail').subscribe(
                     (res: Response) => {
                         console.log('it never gets here');
                         console.log(res)
                         if …
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asynchronous angular2-forms angular

7
推荐指数
1
解决办法
2915
查看次数