Is it wrong to transform/unserialize xml to an array to interface with it?

Question

Consider a SOAP response with lots of nodes, I've noticed some developers using a PEAR Unserialize class while I've always been using simple_xml. Are there any disadvantages to interfacing if you aren't really doing any XML transformation or rendering but simply using data from it.

Answer 1

XML as a data structure has no direct translation into array form. Arrays don't truly support the mix of attributes, values, namespaces, etc. that XML does.

However, with SOAP and other VERY SIMPLE kinds of XML that are really just storing values in custom-named elements, you can convert that into an array without substantial penalty.

Of course, you lose the ability to use things like XPath, but sometimes the simple familiarity of an array is worth the tradeoffs.

Answer 2

If your XML data fits in an array, then this is fine. Most XML schemas are more complex than that and need a tree structure.

De-serializing your XML into some more convenient runtime structure is very common, XML is somewhat expensive to traverse, its designed for data interchange rather than for data access, so it's often wisest to just parse the whole document once.