Lapatniova/DDI-R: insert_universe v1.0

This release contains the R script insert_universe, designed to automate the insertion of DDI <universe> metadata at the variable level in DDI XML files exported from Nesstar or NADA. The script allows users to avoid manually filling the Universe / Filter field by using an external Excel mapping file. Key Features: Checks if variables in the Excel mapping exist in the XML file Creates <universe> tags if they do not exist Updates existing <universe> tags if they already exist Leaves all other metadata in the XML unchanged Required Files: DDI XML file exported from Nesstar or NADA, containing <var> elements with a name attribute Excel mapping file with exactly two columns: variable → variable name (must match the XML) universe → universe/filter text to insert