Redirect to customer login page with filled email field

Question

Please advice: I'm redirecting through JS to customer login page customer/account/login and I want that customer email field should be already filled with some value, which I provide.

Answer 1

Before you redirect to the customer/account/login, also send a Ajax call with this code:

            $.ajax ({
                type : "POST",
                url : "<?php echo $block->getUrl("some/controller/url")?>?isAjax=true",
                showLoader : true,
                data : {
                    request : 'filled_email',
                    email : 'your_custom_email',
                },
                success : function () {
                    window.location.href = "<?php echo $block->getUrl('customer/account/login')?>";
                }
            })

and in the Controller, use this:

/**
 * @var \Magento\Framework\Registry
 */
protected $_coreRegistry;

public function __construct(
        \Magento\Customer\Model\Session $session,
        ResultJsonFactory $resultJsonFactory,
        \Magento\Framework\Registry $registry,
        \Magento\Framework\App\Action\Context $context
    ) {
        $this->_session = $session;
        $this->resultJsonFactory = $resultJsonFactory;
        $this->_coreRegistry = $registry;
        return parent::__construct($context);
    }

    public function execute()
    {
        $param = $this->getRequest()->getParams();
        $request = $param['request'];
        if ($request == 'filled_email') {
            $this->_session->setFilledEmail(true);
            $this->_session->setEmailFill($param['email']);
        }
        return $this->resultJsonFactory->create()->setData(['registry' => 'success']);
        // TODO: Implement execute() method.
    }

Finally, add your custom Block within template in customer_account_login.xml to check if the $this->_session->getFilledEmail() == true so filled the email field with the $this->_session->getEmailFill() value. Don't forget to reset the session after done.

Hope it help!