How to assign custom values to mat-checkbox?

Question

I want to attach my status field with mat-checkbox and want to get the value in the form of a string as we use to get in Material-1.

I am looking for an alternative of ng-true-value="'ACTIVE'" ng-false-value="'INACTIVE'" in Material-7.

G. Tranter · Answer 1 · 2022-05-26T17:52:15.557

You can implement this by using the value property of MatCheckbox and listening to changes. For example:

HTML

<mat-checkbox [value]="falseValue" (change)="checkboxChange($event.source, $event.checked)">
  Check me!
</mat-checkbox>

TS

falseValue = 'No'
trueValue = 'Yes';

checkboxChange(checkbox: MatCheckbox, checked: boolean) {
  checkbox.value = checked ? this.trueValue : this.falseValue;
}

This can be implemented as a directive for simple reusability:

TS

import {Directive, Input} from '@angular/core';
import {MatCheckbox} from '@angular/material/checkbox';

@Directive({
  selector: 'mat-checkbox[checkboxValue]',
  exportAs: 'checkboxValue'
})
export class CheckboxValueDirective {

  @Input('checkboxValue') checkbox: MatCheckbox;
  @Input() falseValue: string = '0';
  @Input() trueValue: string = '1';

  ngOnInit() {
    this.checkbox.value = this.checkbox.checked ? this.trueValue : this.falseValue;
    this.checkbox.registerOnChange((checked: boolean) => {
      this.checkbox.value = checked ? this.trueValue : this.falseValue;
    })
  }
}

Usage:

<mat-checkbox #checkbox [checkboxValue]="checkbox" trueValue="Yes" falseValue="No" [checked]="true">
  Check me!
</mat-checkbox>

Here is the directive example on StackBlitz: https://stackblitz.com/edit/angular-aapsr6?file=app/checkbox-value-directive.ts

may be you can answer, https://stackoverflow.com/questions/65429846/loop-through-nested-formgroup-and-change-each-form-control-value-to-null-if-it-h — anonymous, Dec 23 '20 at 19:45

score 1 · Answer 2 · edited Feb 28 '20 at 17:31

I used an approach similar to the comment above. Saving the values of several checkboxes in an array called filtroStatus

filtroStatus: string[] = [];    
checkboxChange(checkbox: MatCheckbox, checked: boolean, statusValue: string){
  if (checked) { 
    this.filtroStatus.push(statusValue);
    statusValue === 'em_analise' ? this.filtroStatus.push('pendente') : null;
    statusValue === 'em_dia' ? this.filtroStatus.push('em_andamento') : null;
    } else {
      const index = this.filtroStatus.indexOf(statusValue);
      const total_excluir = statusValue ==='em_analise' || 'em_dia' ? 2 : 1;

      index >= 0 ? this.filtroStatus.splice(index, total_excluir) : null ; 
    }
}

yumitoya8569 · Answer 3 · 2021-03-10T08:37:08.260

For someone looking for a simple answer

TS:

import { Directive, Input } from '@angular/core';
import { ControlValueAccessor } from '@angular/forms';
import { MatCheckbox } from '@angular/material/checkbox';

@Directive({
  selector: 'mat-checkbox[appCheckboxValue]'
})
export class CheckboxValueDirective implements ControlValueAccessor {
  @Input() trueValue = true;
  @Input() falseValue = false;

  constructor(@Optional() @Self() private ngControl: NgControl, private checkbox: MatCheckbox) {
    if (this.ngControl) {
      this.ngControl.valueAccessor = this;
    }
  }

  writeValue(value: any): void {
    this.checkbox.writeValue(value === this.trueValue);
  }

  registerOnChange(fn: any): void {
    this.checkbox.registerOnChange((checked: boolean) => {
      fn(checked ? this.trueValue : this.falseValue);
    });
  }

  registerOnTouched(fn: any): void {
    this.checkbox.registerOnTouched(fn);
  }

  setDisabledState?(isDisabled: boolean): void {
    this.checkbox.setDisabledState(isDisabled);
  }
}

HTML:

<mat-checkbox appCheckboxValue trueValue="ACTIVE" falseValue="INACTIVE" [(ngModel)]="myCheck">
</mat-checkbox>

How to assign custom values to mat-checkbox?

3 Answers3