[galaxy-user] listing attributes of data input

Dear all, I was wondering if there is a place within the Galaxy content (a config, an xml file) that gives me some handles on how to address attributes of data input. For example, I can get the 'file_name' of data input, by addressing this attr as 'input.file_name', and for example, the original name of the data file can be addressed with 'input.name'. Anyone any clues where I can find this info? Freddy de Bree