UUID
The UUID rule checks that a field's value is a validly formatted universally unique identifier — the standard 32-hex-digit, hyphen-separated pattern like 550e8400-e29b-41d4-a716-446655440000. It's the check to reach for on fields like a resource ID passed in a URL, an API key or token field, or any input where the user is expected to paste an identifier generated by your own system, catching a mistyped or truncated ID before it's used to look something up. This is a format check only — it confirms the value looks like a UUID, not that a record with that ID actually exists; pairing it with the Exists rule covers that second half when it matters.
#Directive Code Snippet
<!DOCTYPE html>
<html lang="en">
...
<form (ngSubmit)="onSubmit(form)" #form="ngForm">
<input uuid type="text" name="<name>" [(ngModel)]="<name>" #<name>="ngModel">
<ng-absolute-validator [formInstance]="<name>"></ng-absolute-validator>
</form>
...
</html>
#Chain Rule Code Snippet
<!DOCTYPE html>
<html lang="en">
...
<form (ngSubmit)="onSubmit(form)" #form="ngForm">
<input rule="uuid" type="text" name="<name>" [(ngModel)]="<name>" #<name>="ngModel">
<ng-absolute-validator [formInstance]="<name>"></ng-absolute-validator>
</form>
...
</html>
#Reactive Form Code Snippet
//component.ts
export class ReactiveComponent{
public form !: FormGroup;
constructor(
private fb : FormBuilder,
private rv : ReactiveValidator,
){this.generteForm()}
generteForm(){
this.form = this.fb.group({
<name> : ['',this.rv.map('uuid',,<CUSTOM_MESSAGE>)]
})
}
}
//component.html
<!DOCTYPE html>
<html lang="en">
...
<form [formGroup]="form">
<input type="text" name="<name>" formControlName="<name>">
<ng-absolute-validator [formInstance]="form.get(<name>)"></ng-absolute-validator>
</form>
...
</html>