xml example

date.R

library("magrittr")
library("stringr")
library("lubridate")
library("xml2")

get_date <- function(xml_blob) {
  # Convert XML clock info into an R list
  xml_list <- xml_blob %>%
    str_replace_all("\\\\n", "") %>%
    read_xml %>%
    as_list

  # Extract date, convert from UTC to Central Time, save as string
  date <- xml_list[["StartTime"]][["DateUtc"]][[1]] %>%
    parse_date_time(orders = "%y-%m-%dT") %>%
    with_tz("America/Chicago") %>%
    format("%Y-%m-%d")
  date
}

get_date(
  '<?xml version=\"1.0\"?>\\n<Clock xmlns:dt=\"urn:schemas-microsoft-com:datatypes\"><Description dt:dt=\"string\">E-Prime Primary Realtime Clock</Description><StartTime><Timestamp dt:dt=\"int\">0</Timestamp><DateUtc dt:dt=\"string\">2013-01-03T15:33:32Z</DateUtc></StartTime><FrequencyChanges><FrequencyChange><Frequency dt:dt=\"r8\">2992520000</Frequency><Timestamp dt:dt=\"r8\">3.43119378004024E+15</Timestamp><Current dt:dt=\"r8\">0</Current><DateUtc dt:dt=\"string\">2013-01-03T15:33:32Z</DateUtc></FrequencyChange></FrequencyChanges></Clock>\\n'
)
# [1] "2013-01-03"