i'm trying to create custom angular 2 validator directive, which inject NgControl like this :
@Directive({
selector: '[ngModel][customValidator]',
providers: [{provide: NG_VALIDATORS, useExisting: CustomValidatorDirective, multi: true}]
})
export class CustomValidatorDirective implements Validator {
private validateFunction: ValidatorFn;
constructor(private control: NgControl) { };
}
But i get the following error:
Cannot instantiate cyclic dependency! NgControl
Does anyone know how i can workarround it, so i can access the ngControl after intialization?
You can inject NgControl via Injector to avoid cyclic dependency.
constructor(private _injector: Injector) { }
ngOnInit() {
console.log(this._injector.get(NgControl))
}
Providers, Pipes, Directives declaration are removed from @Component or @Directive decorators after RC6 or RC7. So you just need to remove
providers: [{provide: NG_VALIDATORS, useExisting: CustomValidatorDirective, multi: true}]
from directive
and add it into @NgModule({}) decorator
@NgModule({
...
providers: [{provide: NG_VALIDATORS, useExisting: CustomValidatorDirective, multi: true}]
})
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