angular2 rc.5自定义输入，无值访问器，用于具有未指定名称的表单控制

问题描述

我有像这样的简单自定义输入组件，

I have simple custom input component like this,

import {Component, Provider, forwardRef} from "@angular/core";
import {ControlValueAccessor, NG_VALUE_ACCESSOR} from "@angular/forms";

const noop = () => {};

const CUSTOM_INPUT_CONTROL_VALUE_ACCESSOR: any = {
  provide: NG_VALUE_ACCESSOR,
  useExisting: forwardRef(() => CustomInputComponent),
  multi: true
};

@Component({
  selector: 'custom-input',
  template: `

          <input class="form-control" 
                 [(ngModel)]="value" name="somename"
                 (blur)="onTouched()">

  `,
  providers: [CUSTOM_INPUT_CONTROL_VALUE_ACCESSOR]
})
export class CustomInputComponent implements ControlValueAccessor{

  //The internal data model
  private _value: any = '';

  //Placeholders for the callbacks
  private _onTouchedCallback: () => void = noop;

  private _onChangeCallback: (_:any) => void = noop;

  //get accessor
  get value(): any { return this._value; };

  //set accessor including call the onchange callback
  set value(v: any) {
    if (v !== this._value) {
      this._value = v;
      this._onChangeCallback(v);
    }
  }

  //Set touched on blur
  onTouched(){
    this._onTouchedCallback();
  }

  //From ControlValueAccessor interface
  writeValue(value: any) {
    this._value = value;
  }

  //From ControlValueAccessor interface
  registerOnChange(fn: any) {
    this._onChangeCallback = fn;
  }

  //From ControlValueAccessor interface
  registerOnTouched(fn: any) {
    this._onTouchedCallback = fn;
  }

}

我有这样的应用程序模块，

and I have app module like this,

/**
 * Created by amare on 8/15/16.
 */
import { NgModule }                     from '@angular/core';
import { BrowserModule }                from '@angular/platform-browser';
import { ReactiveFormsModule, FormsModule }          from '@angular/forms';
import { AppComponent }                 from './app/app.component';
import {CustomInputComponent} from "./app/shared/custom.input.component";
import {RouterModule} from "@angular/router";
@NgModule({
  imports: [ BrowserModule, ReactiveFormsModule, FormsModule, RouterModule ],
  declarations: [ AppComponent, CustomInputComponent],
  bootstrap: [ AppComponent ]
})
export class AppModule {  
}

和主要

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { AppModule }              from './app.module';

platformBrowserDynamic().bootstrapModule(AppModule);

我已经在一个组件中使用了自定义输入，如下所示，但是却得到了没有用于未指定名称属性的表单控件的无值访问器".

and I have used my custom input in one of my components as shown below, but am getting 'No value accessor for form control with unspecified name attribute'.

<custom-input name="firstName" [(ngModel)]="firstName"></custom-input>

和app.component看起来像这样

and the app.component looks like this

import { Component } from '@angular/core';

@Component({
  moduleId: module.id,
  selector: 'app-root',
  templateUrl: 'app.component.html',
  styleUrls: ['app.component.css']
})
export class AppComponent {
  title = 'app works!';

  firstName: string;
}

推荐答案

在主机中的自定义输入组件中添加ngDefaultControl解决了该问题，谢谢@danieleds

adding ngDefaultControl to the custom input component in the host solved the issue, thanks @danieleds

这篇关于angular2 rc.5自定义输入，无值访问器，用于具有未指定名称的表单控制的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！