How to add a newsletter checkbox into Magento customer login form

Question

I want to add the Newsletter checkbox into the Magento2 Customer Login form, when the user clicks the submit button the form validated the email and password, and the newsletter checkbox's state (only if checked) saves into a database under "CUSTOMER INFORMATION -> Newsletter".

How do I do that? Please help. Thank you in advance.

Answer 1

Add checkbox in registration form is a valid thing but in login page is I don't think it's a good way. You can add this in registration form as below

vendor/magento/module-customer/view/frontend/templates/form/register.phtml

<?php if ($block->isNewsletterEnabled()): ?>
    <div class="field choice newsletter">
        <input type="checkbox" name="is_subscribed" title="<?php /* @escapeNotVerified */ echo __('Sign Up for Newsletter') ?>" value="1" id="is_subscribed"<?php if ($block->getFormData()->getIsSubscribed()): ?> checked="checked"<?php endif; ?> class="checkbox">
        <label for="is_subscribed" class="label"><span><?php /* @escapeNotVerified */ echo __('Sign Up for Newsletter') ?></span></label>
    </div>
    <?php /* Extensions placeholder */ ?>
    <?php echo $block->getChildHtml('customer.form.register.newsletter')?>
<?php endif ?>