Angular 2 error- There is no directive with “expor

2019-02-17 01:44发布

问题:

I am using angular 2 forms in my application and i have created the forms based on given link.

https://angular.io/docs/ts/latest/guide/forms.html

In this for validation and to use forms APIs, i have set the ngModel values like #name="id" #id="ngModel" and which throws script error. But its resolved if i set #id="ngModel" as #id="ngForm". But for my case i have to set my model value to ngModel.

Below is my html page.

 <form (ngSubmit)="onSubmit()" #myForm="ngForm">
  <div class="form-group">
  <label class="control-label" for="id">Employee ID</label>
    <input type="text" class="form-control" required [(ngModel)]="model.id" #name="id"  #id="ngModel" >
    <div [hidden]="id.valid || id.pristine" class="alert alert-danger">
      Employee ID is required
    </div>
  </div>
  <div class="form-group">
    <label for="name">Employee Name</label>
    <input type="text" class="form-control" [(ngModel)]="model.name" name="name" #name="ngModel" required>
        <div [hidden]="name.valid || name.pristine" class="alert alert-danger">
      Employee ID is required
        </div>
  </div>
  <div class="form-group">
    <label for="DOJ">DOJ</label>
    <input class="form-control" required [(ngModel)]="model.DOJ" name="DOJ" #DOJ="ngModel"  />
    <div [hidden]="DOJ.valid || DOJ.pristine" class="alert alert-danger">
      DOJ is required
    </div>
  </div>
  <button type="submit" class="btn btn-default" [disabled]="!myForm.form.valid">Submit</button>
</form>

Below is my issue.

      EXCEPTION: Template parse errors:
       There is no directive with "exportAs" set to "ngModel" ("
         <div>
          <h1>My Form</h1>
             <form (ngSubmit)="onSubmit()" [ERROR ->]#myForm="ngModel">
             <div class="form-group>
            <label class="control-label" for="id">Employee"):AppComponent@3:34

I have checked with more questions and answers, most of them said to update angular2 version to RC4 so i have updated my application to rc4 but still i am facing this issue.

Below is my ts file:

import {Component} from '@angular/core';
import { disableDeprecatedForms, provideForms , NgForm} from '@angular/forms';
import {CORE_DIRECTIVES, FORM_DIRECTIVES, FormBuilder,Validators,Control,ControlGroup } from '@angular/common';


@Component({
selector: 'ej-app',    
templateUrl: 'app/app.component.html',
directives: [ CORE_DIRECTIVES,FORM_DIRECTIVES]  
})
  export class AppComponent {
  model = new Employees(null,'','');
    onSubmit() { alert("values submitted")}
   constructor() {
     }
     }
        export class Employees {
         constructor( public id: number,public name: string, public DOJ: String ) {  }
}

回答1:

Don't mix the new and old forms module.

import {CORE_DIRECTIVES, FORM_DIRECTIVES, FormBuilder,Validators,Control,ControlGroup } from '@angular/common';

imports forms stuff from @angular/common. If you use the new forms

bootstrap(AppComponent, [disableDeprecatedForms(), provideForms()])

then use instead

import {FORM_DIRECTIVES, FormBuilder,Validators,Control,ControlGroup } from '@angular/forms';


回答2:

Do not import the FORM_DIRECTIVES and CORE_DIRECTIVES because they are deprecated, instead make sure that you import the NgForm. You can use the following:

import {FormGroup, FormBuilder, FormControl, Validators, NgForm } from '@angular/forms';