Magento: how to create a child block programmatically?

Question

I have a page that has some template block included programmatically as follows:

public function indexAction() {
    $this->loadLayout();
    $block = $this->getLayout()
        ->createBlock('core/template')
        ->setTemplate('somefolder/sometemplate.phtml');

    $this->getLayout()->getBlock('content')->append($block);
    $this->renderLayout();

}

I would like to put inside the sometemplate.phtml, $this->getChildHtml('somechild') to insert another block.

I tried to

        $box = $this->getLayout()
        ->createBlock('page/html')
        ->setTemplate('somefolder/somechild.phtml');
        $block->append($box);

But didn't work. How can I do it?

Answer 1

I solved the problem by using setChild method as follows:

$block->setChild('somealias',$childBlock);

And so I can use

<?php echo $this->getChildHtml('somealias'); ?>

Answer 2

To add up to Ricardo Martins's answer
If you need it in a block directly you can do what product price does

Mage_Catalog_Block_Product:

public function getPriceHtml($product)
{
    $this->setTemplate('catalog/product/price.phtml');
    $this->setProduct($product);
    return $this->toHtml();
}