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notBlank

Validate that a string is not empty and not whitespace-only.

Signature​

NguardValidators.String.notBlank: ValidatorFn

A parameterless validator — used directly without invocation.

Reactive forms​

import { FormControl } from '@angular/forms';
import { NguardValidators } from 'ng-nguard';

const title = new FormControl('', [NguardValidators.String.notBlank]);

Template-driven forms​

<input ngModel name="title" nguardNotBlank />

Error key​

{ notBlank: true }

Notes​

  • The check is value.trim().length > 0.
  • Empty strings fail; strings with only spaces, tabs, newlines fail.
  • A string with at least one non-whitespace character passes — ' a ' is valid.
  • null, undefined, non-string inputs all fail.

See also​

  • Angular's Validators.required — fails on empty but not on whitespace-only. Use notBlank when whitespace must also be rejected.
  • minLength — stricter character-count constraint