---
name: "HTML::Widget::Constraint::Callback"
section: "3pm"
platform: "linux"
package: "libhtml-widget-perl"
version: "1.11-7"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/HTML::Widget::Constraint::Callback"
---

# HTML::Widget::Constraint::Callback(3pm)

Callback Constraint

## NAME

HTML::Widget::Constraint::Callback - Callback Constraint

## SYNOPSIS

```
    my $c = $widget->constraint( 'Callback', 'foo' )->callback(sub {
        my $value=shift;
        return 1;
    });
```

## DESCRIPTION

A callback constraint which will only be run once for each submitted value  of each named field.

## METHODS

### callback

### cb

Arguments: \\&callback

Define the callback to be used for validation.

"cb" is an alias for "callback".

### validate

perform the actual validation.

## AUTHOR

Sebastian Riedel, `"sri@oook.de"`

Marcus Ramberg, `"mramberg@cpan.org"`

## LICENSE

This library is free software, you can redistribute it and/or modify it under the same terms as Perl itself.