NgxGroupValidator

Angular 8+ conditional validation rules for FormGroup

Demo available here

#### Example
```typescript
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
``shell script
npm install ngx-group-validator
``
``shell script
yarn add ngx-group-validator
```