NgxGroupValidator

Angular 8+ conditional validation rules for FormGroup

Demo available here

Example

this.form = this.fb.group({
      checkbox: [false],
      comment: ['']
    }, {
      validators: NgxGroupValidators.sync({
        comment: [
          {
            condition: {
              paths: ['checkbox'],
              check: (a) => a.value === true
            },
            validators: Validators.required
          }
        ]
      })
    });

How it works

Validate comment control than, and only then, when described in condition part check function will return true. And comment control will be validated with validators part of configuration.

Realize that the every control in configuration can have many conditions. And each condition has own check function, and each condition validate control with it's own validation rules.

Instalation

npm install ngx-group-validator

yarn add ngx-group-validator