Change customer group based on custom checkbox magento 2?

Question

<form class="form create account form-create-account" action="<?= $block->escapeUrl($block->getPostActionUrl()) ?>" method="post" id="form-validate" enctype="multipart/form-data" autocomplete="off">
<?= /* @noEscape */ $block->getBlockHtml('formkey'); ?>
<fieldset class="fieldset create info">
    <legend class="legend"><span><?= $block->escapeHtml(__('Personal Information')) ?></span></legend><br>
    <input type="hidden" name="success_url" value="<?= $block->escapeUrl($block->getSuccessUrl()) ?>">
    <input type="hidden" name="error_url" value="<?= $block->escapeUrl($block->getErrorUrl()) ?>">
    <input type="hidden" name="invitecode" value="<?= $this->getUrl('*/*/*', ['_current' => true, '_use_rewrite' => true]) ?>">
    <?= $block->getLayout()->createBlock('Magento\Customer\Block\Widget\Name')->setObject($block->getFormData())->setForceUseCustomerAttributes(true)->toHtml() ?>
    <?php if ($block->isNewsletterEnabled()): ?>
        <div class="field choice newsletter">
            <input type="checkbox" name="is_subscribed" title="<?= $block->escapeHtmlAttr(__('Sign Up for Newsletter')) ?>" value="1" id="is_subscribed"<?php if ($block->getFormData()->getIsSubscribed()): ?> checked="checked"<?php endif; ?> class="checkbox">
            <label for="is_subscribed" class="label"><span><?= $block->escapeHtml(__('Sign Up for Newsletter')) ?></span></label>
        </div>

Want to check here if below checkbox (is_supplier) is Checked then assign a particular customer group

        <div class="field choice is_supplier">
            <input type="checkbox" name="is_supplier" title="<?php /* @escapeNotVerified */ echo __('Is Supplier') ?>" value="6" id="is_supplier" class="checkbox">
            <label for="is_seller" class="label"><span><?php /* @escapeNotVerified */ echo __('Is Supplier') ?></span></label>
        </div>



        <?php /* Extensions placeholder */ ?>
        <?= $block->getChildHtml('customer.form.register.newsletter') ?>
    <?php endif ?>

    <?php $_dob = $block->getLayout()->createBlock('Magento\Customer\Block\Widget\Dob') ?>
    <?php if ($_dob->isEnabled()): ?>
        <?= $_dob->setDate($block->getFormData()->getDob())->toHtml() ?>
    <?php endif ?>

    <?php $_taxvat = $block->getLayout()->createBlock('Magento\Customer\Block\Widget\Taxvat') ?>
    <?php if ($_taxvat->isEnabled()): ?>
        <?= $_taxvat->setTaxvat($block->getFormData()->getTaxvat())->toHtml() ?>
    <?php endif ?>

    <?php $_gender = $block->getLayout()->createBlock('Magento\Customer\Block\Widget\Gender') ?>
    <?php if ($_gender->isEnabled()): ?>
        <?= $_gender->setGender($block->getFormData()->getGender())->toHtml() ?>
    <?php endif ?>
</fieldset>
<?php if ($block->getShowAddressFields()): ?>
    <fieldset class="fieldset address">
        <legend class="legend"><span><?= $block->escapeHtml(__('Address Information')) ?></span></legend><br>
        <input type="hidden" name="create_address" value="1" />

        <?php $_company = $block->getLayout()->createBlock('Magento\Customer\Block\Widget\Company') ?>
        <?php if ($_company->isEnabled()): ?>
            <?= $_company->setCompany($block->getFormData()->getCompany())->toHtml() ?>
        <?php endif ?>

        <?php $_telephone = $block->getLayout()->createBlock('Magento\Customer\Block\Widget\Telephone') ?>
        <?php if ($_telephone->isEnabled()): ?>
            <?= $_telephone->setTelephone($block->getFormData()->getTelephone())->toHtml() ?>
        <?php endif ?>

        <?php $_fax = $block->getLayout()->createBlock('Magento\Customer\Block\Widget\Fax') ?>
        <?php if ($_fax->isEnabled()): ?>
            <?= $_fax->setFax($block->getFormData()->getFax())->toHtml() ?>
        <?php endif ?>

        <?php $_streetValidationClass = $this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('street'); ?>

        <div class="field street required">
            <label for="street_1" class="label"><span><?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('street') ?></span></label>
            <div class="control">
                <input type="text" name="street[]" value="<?= $block->escapeHtmlAttr($block->getFormData()->getStreet(0)) ?>" title="<?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('street') ?>" id="street_1" class="input-text <?= $block->escapeHtmlAttr($_streetValidationClass) ?>">
                <div class="nested">
                    <?php $_streetValidationClass = trim(str_replace('required-entry', '', $_streetValidationClass)); ?>
                    <?php for ($_i = 2, $_n = $this->helper('Magento\Customer\Helper\Address')->getStreetLines(); $_i <= $_n; $_i++): ?>
                        <div class="field additional">
                            <label class="label" for="street_<?= /* @noEscape */ $_i ?>">
                                <span><?= $block->escapeHtml(__('Address')) ?></span>
                            </label>
                            <div class="control">
                                <input type="text" name="street[]" value="<?= $block->escapeHtml($block->getFormData()->getStreetLine($_i - 1)) ?>" title="<?= $block->escapeHtmlAttr(__('Street Address %1', $_i)) ?>" id="street_<?= /* @noEscape */ $_i ?>" class="input-text <?= $block->escapeHtmlAttr($_streetValidationClass) ?>">
                            </div>
                        </div>
                    <?php endfor; ?>
                </div>
            </div>
        </div>

        <div class="field required">
            <label for="city" class="label"><span><?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('city') ?></span></label>
            <div class="control">
                <input type="text" name="city" value="<?= $block->escapeHtmlAttr($block->getFormData()->getCity()) ?>" title="<?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('city') ?>" class="input-text <?= $block->escapeHtmlAttr($this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('city')) ?>" id="city">
            </div>
        </div>

        <div class="field region required">
            <label for="region_id" class="label"><span><?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('region') ?></span></label>
            <div class="control">
                <select id="region_id" name="region_id" title="<?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('region') ?>" class="validate-select region_id" style="display:none;">
                    <option value=""><?= $block->escapeHtml(__('Please select a region, state or province.')) ?></option>
                </select>
                <input type="text" id="region" name="region" value="<?= $block->escapeHtml($block->getRegion()) ?>" title="<?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('region') ?>" class="input-text <?= $block->escapeHtmlAttr($this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('region')) ?>" style="display:none;">
            </div>
        </div>

        <div class="field zip required">
            <label for="zip" class="label"><span><?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('postcode') ?></span></label>
            <div class="control">
                <input type="text" name="postcode" value="<?= $block->escapeHtmlAttr($block->getFormData()->getPostcode()) ?>" title="<?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('postcode') ?>" id="zip" class="input-text validate-zip-international <?= $block->escapeHtmlAttr($this->helper('Magento\Customer\Helper\Address')->getAttributeValidationClass('postcode')) ?>">
            </div>
        </div>

        <div class="field country required">
            <label for="country" class="label"><span><?= /* @noEscape */ $block->getAttributeData()->getFrontendLabel('country_id') ?></span></label>
            <div class="control">
                <?= $block->getCountryHtmlSelect() ?>
            </div>
        </div>
        <?php $addressAttributes = $block->getChildBlock('customer_form_address_user_attributes');?>
        <?php if ($addressAttributes): ?>
            <?php $addressAttributes->setEntityType('customer_address'); ?>
            <?php $addressAttributes->setFieldIdFormat('address:%1$s')->setFieldNameFormat('address[%1$s]');?>
            <?php $block->restoreSessionData($addressAttributes->getMetadataForm(), 'address');?>
            <?= $addressAttributes->setShowContainer(false)->toHtml() ?>
        <?php endif;?>
        <input type="hidden" name="default_billing" value="1">
        <input type="hidden" name="default_shipping" value="1">
    </fieldset>

<?php endif; ?>
<fieldset class="fieldset create account" data-hasrequired="<?= $block->escapeHtmlAttr(__('* Required Fields')) ?>">
    <legend class="legend"><span><?= $block->escapeHtml(__('Sign-in Information')) ?></span></legend><br>
    <div class="field required">
        <label for="email_address" class="label"><span><?= $block->escapeHtml(__('Email')) ?></span></label>
        <div class="control">
            <input type="email" name="email" autocomplete="email" id="email_address" value="<?= $block->escapeHtmlAttr($block->getFormData()->getEmail()) ?>" title="<?= $block->escapeHtmlAttr(__('Email')) ?>" class="input-text" data-mage-init='{"mage/trim-input":{}}' data-validate="{required:true, 'validate-email':true}">
        </div>
    </div>
    <div class="field password required">
        <label for="password" class="label"><span><?= $block->escapeHtml(__('Password')) ?></span></label>
        <div class="control">
            <input type="password" name="password" id="password"
                   title="<?= $block->escapeHtmlAttr(__('Password')) ?>"
                   class="input-text"
                   data-password-min-length="<?= $block->escapeHtmlAttr($block->getMinimumPasswordLength()) ?>"
                   data-password-min-character-sets="<?= $block->escapeHtmlAttr($block->getRequiredCharacterClassesNumber()) ?>"
                   data-validate="{required:true, 'validate-customer-password':true}"
                   autocomplete="off">
            <div id="password-strength-meter-container" data-role="password-strength-meter" aria-live="polite">
                <div id="password-strength-meter" class="password-strength-meter">
                    <?= $block->escapeHtml(__('Password Strength')) ?>:
                    <span id="password-strength-meter-label" data-role="password-strength-meter-label">
                        <?= $block->escapeHtml(__('No Password')) ?>
                    </span>
                </div>
            </div>
        </div>

    </div>
    <div class="field confirmation required">
        <label for="password-confirmation" class="label"><span><?= $block->escapeHtml(__('Confirm Password')) ?></span></label>
        <div class="control">
            <input type="password" name="password_confirmation" title="<?= $block->escapeHtmlAttr(__('Confirm Password')) ?>" id="password-confirmation" class="input-text" data-validate="{required:true, equalTo:'#password'}" autocomplete="off">
        </div>
    </div>
    <?= $block->getChildHtml('form_additional_info') ?>
</fieldset>
<div class="actions-toolbar">
    <div class="primary">
        <button type="submit" class="action submit primary" title="<?= $block->escapeHtmlAttr(__('Create an Account')) ?>"><span><?= $block->escapeHtml(__('Create an Account')) ?></span></button>
    </div>
    <div class="secondary">
        <a class="action back" href="<?= $block->escapeUrl($block->getBackUrl()) ?>"><span><?= $block->escapeHtml(__('Back')) ?></span></a>
    </div>
</div>

Answer 1

You need to create observer for it.

**Step 1:** First create simple Module with necessary(mudule.xml and registration.php) files.

**Step 2:** create file etc/frontend/events.xml in your module.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="customer_register_success">
        <observer name="save_customer_group" instance="Vendorname\Modulename\Observer\SupplierCustomerGroup" />
    </event>
</config>

Step 3. Create Observer Folder and inside it create SupplierCustomerGroup.php file

<?php

namespace Vendorname\Modulename\Observer;

use Magento\Framework\Event\ObserverInterface;
use Magento\Customer\Api\CustomerRepositoryInterface;
use Magento\Framework\Message\ManagerInterface;

Class SupplierCustomerGroup implements ObserverInterface {

    public $_customerRepositoryInterface;
    public $_messageManager;

    public function __construct(
    CustomerRepositoryInterface $customerRepositoryInterface, ManagerInterface $messageManager
    ) {
        $this->_customerRepositoryInterface = $customerRepositoryInterface;
        $this->_messageManager = $messageManager;
    }

    public function execute(\Magento\Framework\Event\Observer $observer) {
        $accountController = $observer->getAccountController();
        $request = $accountController->getRequest();
        $group_id = $request->getParam('group_id');
        if ($group_id != '') {
            try {
                $customerId = $observer->getCustomer()->getId();
                $customer = $this->_customerRepositoryInterface->getById($customerId);
                $customer->setGroupId($group_id);
                $this->_customerRepositoryInterface->save($customer);
            } catch (Exception $e) {
                $this->_messageManager->addErrorMessage(__('Something went wrong! Please try again.'));
            }
        }
    }

}

Step 4: In Registration File

Implement Logic to jquery if checkbox click then group_id send to as per customer group(General 1 ,Wholesale 2....)  and you will get this in Observer file with below code.


$group_id = $request->getParam('group_id');