Captcha

Display the PNG captcha image
Validate the captcha
Captcha customization

Display the PNG captcha image

On the page class containing the form, add a method to generate a captcha and store the text in a session variable:

<?php

declare(strict_types=1);

class Acme_Page_Contact extends Core_Page
{
    public function getCaptcha(): string
    {
        $captcha = new Captcha();

        App::session()->set('captcha', $captcha->getText());

        return $captcha->inline();
    }
}

Display the captcha image in the form:

<form action="<?= $this->getUrl('contact/post/') ?>" method="post">
    <img src="<?= $this->getCaptcha() ?>" alt="This is a textual captcha" />
    <input type="text" name="secure" value="" />

    <input type="submit" value="Submit" />
</form>

Validate the captcha

When the form is submitted, check the captcha's validity:

<?php

declare(strict_types=1);

class Acme_Page_Contact_Post extends Core_Page
{
    public function execute(): void
    {
        $dataPost = $this->dataPost();

        $captcha = App::session()->pull('captcha');

        if ($dataPost->getData('secure') !== $captcha) {
            $this->setErrorMessage('Captcha is not correct');
            $this->redirect('contact.html');
        }

        // Form Processing
    }
}

Captcha customization

Method	Description	Example
setFont	Absolute monospace font file path in ttf format	/var/www/magework/fonts/courier.ttf
setColor	Text color in hexadecimal	#ffffff
setBackground	Background color in hexadecimal	#000000
setChars	Allowed characters (included in the font)	abcdefghijkmnopqrstuvwxyz23456789
setLength	Text length	5
setWidth	Image width in px	105
setHeight	Image height in px	40
setFontSize	Font size	20
setPaddingTop	Image padding top in px	28
setPaddingLeft	Image padding left in px	12
setAngle	Text orientation angle	5

<?php

$captcha = new Captcha();
$captcha->setColor('#ffffff')->setBackground('#000000');