Angular No Whitespace Allowed Vaidator Directive

<md-input-container class="admin-form">
  <input md-input placeholder="Block Title" nfNoSpaces [(ngModel)]="block.title" id="block-{{ block.id }}-input-name" name="title"
    #title="ngModel">
  <md-hint [ngStyle]="{'color': 'red'}" align="start" *ngIf="!title.valid && !title.pristine">Title is required.</md-hint>
</md-input-container>


Be sure to include ref to directive in module declarations array.

no-whitespace.directive.ts

import { Directive, Input, OnChanges, SimpleChanges } from '@angular/core';
import { NoWhitespaceValidator } from './no-whitespace.validator';
import { Validator, AbstractControl, Validators, NG_VALIDATORS } from '@angular/forms';

/**
 * This validator works like "required" but it does not allow whitespace either
 *
 * @export
 * @class NoWhitespaceDirective
 * @implements {Validator}
 */
@Directive({
	selector: '[nfNoSpaces]',
	providers: [{ provide: NG_VALIDATORS, useExisting: NoWhitespaceDirective, multi: true }]
})
export class NoWhitespaceDirective implements Validator {

	private valFn = NoWhitespaceValidator();
	validate(control: AbstractControl): { [key: string]: any } {
		return this.valFn(control);
	}
}

no-whitespace.validator.spec.ts

import { AbstractControl } from '@angular/forms';
import { NoWhitespaceValidator } from './no-whitespace.validator';

describe('Whitespace Validator', () => {

  let validatorFn = NoWhitespaceValidator();

  it('empty string is invalid', () => {
    let control = { value: '' }
    let result = validatorFn(control as AbstractControl)
    expect(result !== null).toBe(true);
    expect(result['whitespace']).toBe('value is only whitespace')
  });

  it('spaces only are invalid', () => {
    let control = { value: '    ' }
    let result = validatorFn(control as AbstractControl)
    expect(result !== null).toBe(true);
  });

  it('null is invalid', () => {
    let control: any = { value: null }
    let result = validatorFn(control as AbstractControl)
    expect(result !== null).toBe(true);
  });

  it('text is not considered invalid', () => {
    let control = { value: 'i have whitespace on the inside' }
    let result = validatorFn(control as AbstractControl)
    expect(result).toBe(null);
  });

});

no-whitespace.validator.ts

import { AbstractControl, ValidatorFn } from '@angular/forms';

export function NoWhitespaceValidator(): ValidatorFn {
  return (control: AbstractControl): { [key: string]: any } => {
    let isWhitespace = (control.value || '').trim().length === 0;
    let isValid = !isWhitespace;
    return isValid ? null : { 'whitespace': 'value is only whitespace' }
  };
}