I need to:
1) Open a XML file to a Lightroom's String
2) Parse some data from It with LrXml
3) Show to the user
I Don't have any ideas to do the first point, please help me.
Use LrFileutils.readFile(). If you need finer control over file i/o, you can use Lua's builtin file library calls (io.open, file:read, etc.) -- see a standard Lua reference for details.
Retrieving data ...