ControlValueAccessor with Error Validation in Angular Material
I had the same problem. I tried all and then finally could resolve using this method:
I added this listener on the custom component. You can also do it 'blur' event.
@HostListener('focusout', ['$event.target'])
onFocusout() {
this.onTouched();
}
And also calling onTouched when setting any value.
writeValue(value: any) {
this.onTouched();
this.Value = value ? value : '';
}
This will create error validation from Angular Material
Typescript:
import { Component, OnInit, Input, EventEmitter, Output, forwardRef, Injector } from '@angular/core';
import { ControlValueAccessor, NG_VALUE_ACCESSOR, FormControl, NgForm, FormGroupDirective, NgControl } from '@angular/forms';
import { ErrorStateMatcher } from '@angular/material';
export class CustomFieldErrorMatcher implements ErrorStateMatcher {
constructor(private customControl: FormControl,private errors:any) { }
isErrorState(control: FormControl | null, form: FormGroupDirective | NgForm | null): boolean {
return this.customControl && this.customControl.touched &&(this.customControl.invalid || this.errors);
}
}
@Component({
selector: 'app-input-textbox',
templateUrl: './input-textbox.component.html',
styleUrls: ['./input-textbox.component.scss'],
providers: [
{
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => InputTextboxComponent),
multi: true
}
]
})
export class InputTextboxComponent implements OnInit, ControlValueAccessor {
@Input() MaxLength: string;
@Input() FocusIn: boolean;
@Input() Width: string;
@Input() Value: string;
@Input() type: string;
@Input() Label: string;
@Input() Hint: string;
@Input() PlaceHolder: string;
@Output() saveValue = new EventEmitter();
@Output() onStateChange = new EventEmitter();
@Input() errors: any = null;
disabled: boolean;
control: FormControl;
constructor(public injector: Injector) {}
ngOnInit(){}
ngAfterViewInit(): void {
const ngControl: NgControl = this.injector.get(NgControl, null);
if (ngControl) {
setTimeout(() => {
this.control = ngControl.control as FormControl;
})
}
}
saveValueAction(e) {
this.saveValue.emit(e.target.value);
}
//control value accessor init
writeValue(value: any) {
this.Value = value ? value : '';
}
onChange(e) {
this.Value = e;
}
onTouched() {
this.onStateChange.emit();
}
registerOnChange(fn: any) { this.onChange = fn; }
registerOnTouched(fn: any) { this.onTouched = fn; }
setDisabledState(isDisabled) { this.disabled = isDisabled; }
errorMatcher() {
return new CustomFieldErrorMatcher(this.control,this.errors)
}
readonly errorStateMatcher: ErrorStateMatcher = {
isErrorState: (ctrl: FormControl) => (ctrl && ctrl.invalid)
};
}
HTML
<div class="input-wrap">
<mat-form-field>
<mat-label>{{Label}}</mat-label>
<input
matInput
[attr.maxlength] = "MaxLength"
[value]="Value ? Value : ''"
[placeholder]="PlaceHolder ? PlaceHolder : ''"
[type]="type ? type: 'text'"
[ngModel]="Value"
[errorStateMatcher]="errorMatcher()"
(input)="onChange($event.target.value)"
(blur)="onTouched()"
(change)="saveValueAction($event)"
(ngModelChange)="Value=$event;onChange($event)"
>
<mat-hint>{{Hint}}</mat-hint>
</mat-form-field>
</div>
Kinda used your answer and the link you provided to come up with this solution:
@Component({
selector: 'app-custom-input',
templateUrl: './custom-input.component.html',
styleUrls: ['./custom-input.component.css'],
providers: [{
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => CustomInputComponent),
multi: true
}]
})
export class CustomInputComponent implements OnInit, ControlValueAccessor {
...
_control: NgControl;
disabled: boolean;
constructor(@Inject(INJECTOR) private injector: Injector) {
}
ngOnInit() {
this._control = this.injector.get(NgControl);
}
...
custom-input.component.html
<div class="input-wrap">
<mat-form-field appearance="outline">
<mat-label>{{Label}}</mat-label>
<input matInput
[formControl]="_control.control" // <== this what makes it work
[attr.maxlength]="MaxLength"
[placeholder]="PlaceHolder ? PlaceHolder : ''"
[type]="type ? type: 'text'"
>
</mat-form-field>
</div>
Note: I'm not binding to MatInput's outputs (yea). the formControl directive that passes the control to MatInput handles that for us.
made an example for you