Magento 2 How to Render Child blocks in controller

Question

I want to remove the 'Proceed to Checkout' button when the qty reaches a specified limit. For that I add a condition check in this page

module-checkout\view\frontend\templates\onepage\link.phtml

On qty update I have added an ajax call to the controller and passing the layouts as the ajax response and load the section. I am following the below link

How to Render an HTML Using an Ajax Call in Magento 2 Module

In my controller I have added the below code

$block = $resultPage->getLayout()
            ->createBlock('Magento\Checkout\Block\Cart')
            ->setTemplate('Magento_Checkout::cart/methods.phtml')
            ->toHtml();

The issue is that, the checkout button is not loading since it is a child of this block.

    <block class="Magento\Checkout\Block\Cart" name="checkout.cart.methods.bottom" template="Magento_Checkout::cart/methods.phtml">
        <container name="checkout.cart.methods" as="methods" label="Payment Methods After Checkout Button">
            <block class="Magento\Checkout\Block\Onepage\Link" name="checkout.cart.methods.onepage.bottom" template="Magento_Checkout::onepage/link.phtml" />
            <block class="Magento\Checkout\Block\QuoteShortcutButtons" name="checkout.cart.shortcut.buttons" />
        </container>
   </block>

Now, I need to render the child blocks along with this.

How can I do this?

Answer 1

How you are creating the new parent block, you will have to create the child blocks and embed them in the block you created:

checkout.cart.methods.bottom

You will do the same as you did for the child blocks, and then using the method addChild to include the child blocks in the parent.

I am pretty sure that there is a better way to achieve the requirements, maybe using knockout JS.