如何在窗体内的自定义控件中使用ngModel? [英] How to use ngModel with a custom control inside a form?
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问题描述
我创建了一个用于处理选择框的组件,现在在提交表单后将其放入表单标记中时,选择结果不会显示在控制台中.
I created a component for handling select box, now when I put it in form tag after submitted form the result of the selection doesn't show up in console.
我的代码有什么问题?我该如何解决?
What's the problem with my code? how can I fix this?
- testOption:是我传递的对象数组,用
@Input
抛出选择框.
- testOption: is array of object I passed throw the select box with
@Input
.
这是选择框组件:
import { Component, OnInit, Input } from '@angular/core';
@Component({
selector: 'input-select',
template:`
<div class="field-select">
<span><icon name="select-arrow" size="10"></icon></span>
<select name="{{name}}" class="field">
<option value="0" disabled selected>{{label}}</option>
<option *ngFor="let option of options" [ngValue]="option.value">{{option.name}}</option>
</select>
</div>
`
})
export class InputSelectComponent implements OnInit {
@Input() label: string;
@Input() name: string;
@Input() options;
// testOptions = [
// {value:'test',name:'test2'},
// {value:'test',name:'test2'}
// ];
constructor() { }
ngOnInit() {
console.log(this.options);
}
}
在html中的用法:
<input-select label="test" name="select2" [options]="testOption"></input-select>
表单html:
<form role="form" class="form" #f="ngForm" (ngSubmit)="onSubmit(f)">
<input class="field" name="name" ngModel type="text" placeholder="n1">
<input-select label="b2" name="select2" [options]="testObject"></input-select>
<input class="field" name="building-type" type="text" ngModel placeholder="b3">
</form>
控制台日志(没有选择框值)
Object {name: "test", building-type: "tset" }
推荐答案
我想我现在遇到了您的问题.
I guess I got your problem now.
您想在自定义组件上实现ControlValueAccessor
,以便在具有ngModel
的表单内使用它!!
You want to implement ControlValueAccessor
on your custom component to use it inside of a form with ngModel
!?
您的组件应如下所示:
@Component({
selector: 'ng2-input-select',
template: `
<div class="field-select">
<select name="{{ name }}" class="field" [(ngModel)]="value" (ngModelChange)="_onChange($event)">
<option value="" disabled selected>{{ label }}</option>
<option *ngFor="let option of options" [value]="option.value">{{ option.name }}</option>
</select>
</div>
`,
providers: [
{ /* idk why or what this will do exactly.. but it works! ;) */
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => SelectBoxComponent),
multi: true
}
]
})
export class SelectBoxComponent implements OnInit, ControlValueAccessor {
@Input() label: string;
@Input() name: string;
@Input() options;
@Input() value: string = '';
// ControlValueAccessor implementation
// ====================================
// call if value was changed inside our component
private _onChange = (_: any) => { };
// call if input was "touched" .. !
private _onTouched = () => { };
// incoming change..
public writeValue(val: any) {
this.value = val;
}
public registerOnChange(fn: (_: any) => void): void { this._onChange = fn; }
public registerOnTouched(fn: () => void): void { this._onTouched = fn; }
}
实时演示: https://plnkr.co/edit/imCJmCoJaeGQiUMcyBwz?p=preview
更新
在表单组件中使用更改检测:
Using change detection in your form-component:
<ng2-input-select ngModel (ngModelChange)="selectBoxChanged($event)" label="b2" name="select2" [options]="testObject"></ng2-input-select>
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