controlvalueaccessor

问题 I have a custom component, it's a wrap for mat-select. How can I use it in others component's? I was reading about formControl and controlValueAccessor, but I don't understand alot. my custom.html <mat-select> <mat-option [value]="opt" *ngFor="let op of opt; index as i">{{opt[i]}}</mat-option> </mat-select> <input matInput> my custom.ts import { Component, OnInit, Input } from '@angular/core'; import { MatFormFieldControl } from '@angular/material/form-field'; @Component({ selector: 'cust

问题 I have a custom component, it's a wrap for mat-select. How can I use it in others component's? I was reading about formControl and controlValueAccessor, but I don't understand alot. my custom.html <mat-select> <mat-option [value]="opt" *ngFor="let op of opt; index as i">{{opt[i]}}</mat-option> </mat-select> <input matInput> my custom.ts import { Component, OnInit, Input } from '@angular/core'; import { MatFormFieldControl } from '@angular/material/form-field'; @Component({ selector: 'cust

问题 What's the difference between ViewChild and ControlValueAccessor in Angular? Seems both of them can access child components, directives, DOM. So curious about the differences in usage, can one do something the other cannot do? 回答1: ControlValueAccesor is for making a custom form control . By steps, a FormControl can store anything, even an object. Imagine two different FormGroups form1=new FormGroup({ name:new FormControl('name') direcction:new FormControl({address:'address',cp:'cp'}) })

问题 What's the difference between ViewChild and ControlValueAccessor in Angular? Seems both of them can access child components, directives, DOM. So curious about the differences in usage, can one do something the other cannot do? 回答1: ControlValueAccesor is for making a custom form control . By steps, a FormControl can store anything, even an object. Imagine two different FormGroups form1=new FormGroup({ name:new FormControl('name') direcction:new FormControl({address:'address',cp:'cp'}) })

问题 What's the difference between ViewChild and ControlValueAccessor in Angular? Seems both of them can access child components, directives, DOM. So curious about the differences in usage, can one do something the other cannot do? 回答1: ControlValueAccesor is for making a custom form control . By steps, a FormControl can store anything, even an object. Imagine two different FormGroups form1=new FormGroup({ name:new FormControl('name') direcction:new FormControl({address:'address',cp:'cp'}) })

问题 What's the difference between ViewChild and ControlValueAccessor in Angular? Seems both of them can access child components, directives, DOM. So curious about the differences in usage, can one do something the other cannot do? 回答1: ControlValueAccesor is for making a custom form control . By steps, a FormControl can store anything, even an object. Imagine two different FormGroups form1=new FormGroup({ name:new FormControl('name') direcction:new FormControl({address:'address',cp:'cp'}) })

问题 What's the difference between ViewChild and ControlValueAccessor in Angular? Seems both of them can access child components, directives, DOM. So curious about the differences in usage, can one do something the other cannot do? 回答1: ControlValueAccesor is for making a custom form control . By steps, a FormControl can store anything, even an object. Imagine two different FormGroups form1=new FormGroup({ name:new FormControl('name') direcction:new FormControl({address:'address',cp:'cp'}) })

问题 To show a kind of real world example, let's say that we want to use the @angular/material's datepicker in our application. We want to use it on a lot of pages, so we want to make it very easy to add it to a form with the same configuration everywhere. To fulfill this need, we create a custom angular component around a <mat-datepicker> with ControlValueAccessor implementation to be able to use [(ngModel)] on it. We want to handle the typical validations in the component, but in the same time,

问题 I have a reactive form. The setup is similar to this: myForm: FormGroup; this.myForm= new FormGroup({ name: new FormControl("", [Validators.required, Validators.maxLength(15), Validators.pattern('...')]), ... }); I use this on my form like this: <input type="text" formControlName="name" /> <div *ngIf="name.errors?.required"> Name is required </div> <div *ngIf="name.errors?.maxlength"> Name must be {{ name.errors.maxlength.requiredLength }} characters </div> <div *ngIf="name.errors?.pattern">

问题 I have a custom ControlValueAccessor which simply appends a currency symbol on an input. @Component({ selector: 'app-currency-input', templateUrl: './currency-input.component.html', styleUrls: ['./currency-input.component.scss'], providers: [ CurrencyPipe, { provide: NG_VALUE_ACCESSOR, useExisting: forwardRef(() => CurrencyInputComponent), multi: true } ] }) export class CurrencyInputComponent implements ControlValueAccessor { @Input() class = ''; currencyValue: string; onChange: (value: