FoxcommerceConfiguration_AdminSection.php

<?php

class FoxcommerceConfiguration_AdminSection extends FoxcommerceAdminSection
{
    protected static $url_segment   = 'ecommerce';
    protected static $url_priority  = 75;
    protected static $url_rule      = '/FoxcommerceConfig/Configuration';
    protected static $menu_title    = 'Basic Configuration';
    protected static $description   = 'Manage the basic config for your shop';
    protected static $tree_class    = 'FoxcommerceConfig';
    protected static $is_subsection = true;

    protected static $url_handlers = [
        'FoxcommerceConfig/Configuration/SettingsForm' => 'SettingsForm',
        'FoxcommerceConfig/Configuration'              => 'Settings'
    ];

    public function init()
    {
        parent::init();
        $this->modelClass = 'FoxcommerceConfig';
    }

    public function getSubsectionFormFields()
    {

        $fields = parent::getSubsectionFormFields();
        $config = FoxcommerceConfig::current();

        $fields->addFieldsToTab('Root.Main', [
            DropdownField::create('TaxStyle', 'Tax style',
                ['Inclusive' => 'Inclusive', 'Exclusive' => 'Exclusive'], $config->TaxStyle),
        ]);

        return $fields;
    }

    public function getSubsectionFormActions()
    {

        $actions = parent::getSubsectionFormActions();
        $actions->add(
            FormAction::create('saveSettings', _t('GridFieldDetailForm.Save', 'Save'))
                      ->setUseButtonTag(true)->addExtraClass('ss-ui-action-constructive'));
        return $actions;
    }

    public function saveSettings($data, CMSForm $form)
    {
        $config           = FoxcommerceConfig::current();
        $config->TaxStyle = $data['TaxStyle'];
        $config->write();

        $form->sessionMessage('Shop basic configuration updated', 'good');
    }

}