import {AbstractControl} from '@angular/forms'; export function URLFormatValidator(control: AbstractControl): {[key: string]: any} | null { const valid = /^(?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~:/?#[\]@!\$&'\(\)\*\+,;=.]+$/.test(control.value); return valid ? null : {'invalidURLFormat': {value: control.value}}; }