Identifying and formatting XML String to readable format in XMLParser

I am working in Swift and I have a set of Data that I can encode as a String like this:

<CONTAINER><Creator type="NSNull"/><Category type="NSNull"/><UMID type="NSArray"><CHILD>d1980b265cbd415c90f5d5f04efcb5df</CHILD><CHILD>7e0252c137c249fc92bd0f844effe27f</CHILD></UMID><Channels type="NSNumber">1</Channels></CONTAINER>

I am looking for a way to format this string as XML with indents so I can use XMLParser to properly read through it, which it currently does not. I imagine NSNull is when the object is empty, I just haven’t seen this format so I don’t know what to search for. Could it be closer to a Dictionary object? If so I’d be happy to format it as that as well.

I’ve also tried to create a XMLDocument from the data, but it doesn’t fix the format.

Source: Swift Questions