REXML's ElementNo.delete_element

Normallly you can use this method for deleting specific elements of a DOM-tree by passing their XPath or Element instance to this method. Since I thought: It’s in the tree so I will simply delete it based from the respective Document#root … not good ;) This will result in quite strange behaviour which alters for example the nodename of the parent element of the element to be removed. In my case I worked on a OPML file with following section:

<outline ...>

   <outline id="someElement" ..../>


Removing the element now using document.root.delete_element(e) caused absolutely nothing. So I had to try something else:


This actually removed the element from the try but resulted in the parent element to be renamed to “outline[5]” where 5 was probably for being the 5th outline of the parent element ;)

Stupid, but if I had read the manualy before playing around with it I would have seen following statement:

This means that any parent can remove any descendant.REXML Documentation

While this IMO also applies for the Document#root element it should at least given me a hint ;)

So what did I learn from this?

e.remove is short and good ;)