Angular 4和打字稿

Question

i need to validate the textbox which is present in form where i dont want user to enter the spaces initially and it should start with alphanumeric and then we can add spaces in between the text.

i am writing the regex code in typescript but it is not working for me.

i am calling allowAlphaNumeric method on keypress in input control

allowAlphaNumeric(event) {
        return event && event.key && event.key.match(this.regExpAlphaNumeric) ? true : false;
    }

<input class="form-control ip-box-css" type="text" formControlName = "campaignName" id="campaignName" (keypress)="allowAlphaNumeric($event)" maxlength="30" placeholder="Enter" required>

where regExpAlphaNumeric: string = '^[^-\s][a-zA-Z0-9_\s-]+$';

the issue is that the regex expression is not considering as string

Please provide some suggestion so that it will work in .ts(typescript) file

Answer 1

Create a form control (or a control in a formGroup)

textboxToValidate: FormControl = new FormControl('', [
  Validators.required,
  Validators.pattern(/^[^-\s][a-zA-Z0-9_\s-]+$/)
]);

Those built-in classes can be imported from the form module

import { FormControl, Validators } from '@angular/forms';