cx-newsletter/activities/1-config_panel_activity.php

<?php

namespace cx_newsletter;

class config_panel_activity
extends activity {
    public function show_after_button() : null {
        return null;
    }

    public function inside_buttons() : array {
        return [ 'save' ];
    }

    public function inside_inputs() : array {
        return [
            'source_address' => 'email',
            'reply_to_address' => 'email',
            'email_count' => 'int',
            'sms_count' => 'int',
            'apikey' => 'string'
        ];          
    }

    public function get_site_template_name() : string {
        return 'config_panel';
    }

    private function validate_result() : ?string { 
        if (!$this->is_validated('source_address')) {
            return 'Source E-Mail address is not valid.';
        }   

        if (!$this->is_validated('reply_to_address')) {
            return 'Reply to E-Mail address it not valid.';
        }

        if (!$this->is_validated('email_count')) {
            return 'Count of the E-Mails is not valid.';
        }

        if (!$this->is_validated('sms_count')) {
            return 'Count of the SMS-es is not valid.';
        }

        if (!$this->is_validated('apikey')) {
            return 'Api Key is not valid.';
        }

        if (strlen($this->get_validated('apikey')) < 16) {
            return 'Api Key must has minimum 16 characters.';
        }

        return null;
    }

    private function save() { 
        $validate = $this->validate_result();

        if ($validate !== null) {
            $this->error_toast($validate);
            return;
        }

        $settings = $this->get_settings();
        
        $settings
        ->save('source_address', $this->get_validated('source_address'))
        ->save('reply_to_address', $this->get_validated('reply_to_address'))
        ->save('email_count', $this->get_validated('email_count'))
        ->save('sms_count', $this->get_validated('sms_count'))
        ->save('apikey', $this->get_validated('apikey'));

        $this->success_toast('Settings had been saved.');
    }

    public function process() : self {
        if ($this->is_received('save')) {
            $this->save();
        }

        $this->set('source_address', $this->get_settings()->get('source_address'));
        $this->set('reply_to_address', $this->get_settings()->get('reply_to_address'));
        $this->set('email_count', $this->get_settings()->get('email_count'));
        $this->set('sms_count', $this->get_settings()->get('sms_count'));
        $this->set('apikey', $this->get_settings()->get('apikey'));

        return $this;
    }
}