Magento. Insert block into another without change template code

Question

I\'ve tried to find solution but with no results. My task is to write module. It should insert some html into existing block.

I noticed that when I used layout .xml file

Answer 1

No, there is not a generic way to add your block to any other block. The reason it works occasionally for you is that there are some block types that just enumerate their children (core/text_list being one of those) and some templates manually do the same (using $this->getChild()).

If you want to add your block underneath a block that fits neither of these criteria, you will need to modify the template to echo that block.