Hey guys, I am writing a small class to build and POST xml. I have a few XML requests that I have to build, i.e.:

1) getAuthKey
2) getUserInfo
3) getUserItems

Now question is this, do I just write functions with the XML echoed out and then populate the values of the XML nodes from params passed in? Or should I build the XML depending on the request with a generic build XML function? This is for a client and since I haven't worked much with XML I would like to know what the industry standard is as I want it to be as professional as possible. Thanks, any input is greatly appreciated.