slug

Validate that a string is a valid URL slug — lowercase alphanumeric characters separated by single dashes, no leading, trailing, or consecutive dashes.

Signature

NguardValidators.String.slug: ValidatorFn

A parameterless validator — used directly without invocation.

Reactive forms

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

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

Template-driven forms

<input ngModel name="slug" nguardSlug />

Error key

{ slug: true }

Notes

• Pattern: ^[a-z0-9]+(?:-[a-z0-9]+)*$.
• Accepts: my-blog-post, post-2024-update, hello.
• Rejects: My-Post (uppercase), -leading, trailing-, double--dash, with space.
• Empty strings fail.

See also

• alphaDash — looser: allows uppercase, underscores, and consecutive dashes
• lowercase — case constraint without dash structure