R dataframe from XML when values are multiple or missing

Question

This question is similar to a previous question, Import all fields (and subfields) of XML as dataframe, but I want to pull out only a subset of the XML data and want to incl

Answer 1

You can use xmlToList and then plyr to get a dataframe you can use

require(XML)
require(plyr)
xD <- xmlParse(xData)
xL <- xmlToList(xD)
ldply(xL, data.frame)
> ldply(xL, data.frame)
   .id     name buildings.building.type buildings.building.bname
1 city   London                landmark             Tower Bridge
2 city New York                 station            Grand Central
3 city    Paris                landmark             Eiffel Tower
  buildings.building.type.1 buildings.building.bname.1
1                   station                   Waterloo
2                                             
3                  landmark                     Louvre

You can pick what you need from this dataframe