how to modify phtml file without override

Question

Generally, in Magento 2, .phtml files have $block->getChildHtml(), allowing us to put extra data in the .phtml by adding a child to the layout.

If some .phtml file don't have such code and we want to put our custom HTML in a specific area, is there an approach to do that? Because overriding the .phtml file in the module will require frequent updates when the original .phtml file is updated.

I am seeking a way to add $block->getChildHtml('custom_block_name') in the .phtml before it renders.

Is there any way to do that?

(For example, I need to add block phtml under the customer name on the registration page.)

Answer 1

One solution is adding the rendering of your block in the toHtml() class that renders the original block:

class View extends \Magento\Catalog\Block\Product\View {

   public function toHtml() {

    $output = $this->getLayout()->createBlock(\Magento\Cms\Block\Block::class)->setBlockId('blog-engagement')->toHtml();
    $output .= parent::toHtml();
    return $output;
   }

}

Remember to setup the preference for this class inside your module to make it work.

Answer 2

Please try using a layout update file

<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
    <update handle="product_view">
        <block class="Magento\Catalog\Block\Product\View" name="product.info" template="Your_Module::product/view.phtml" />
    </update>
</page>

Thank You!