dataframeFromJSON using jsonlite

gistfile1.r

isNestedDataFrame <- function(df) {
  cols = colnames(df)
  for (col in 1:ncol(df)) {
    c <- df[[cols[col]]]
    if (is.data.frame(c)) {
      return (TRUE)
    }
  }
  return (FALSE)
}

normalizeDataFrame <- function(df) {
  library(stringr)
  cols = colnames(df)
  for (col in 1:ncol(df)) {
    # print(cols[col])
    c <- df[[cols[col]]]
    if (is.data.frame(c)) {
      # Reccursive normalization
      if (isNestedDataFrame(c))
        c <- normalizeDataFrame(c)
      subcols <- colnames(c)
      for (subcol in 1:ncol(c)) {
        if (subcols[subcol] != 'X') {
          newcol <- str_c(cols[col], '.', subcols[subcol])
          # print(newcol)
          df[newcol] <- (c[subcols[subcol]])
        }
      }
      df <- dropColumns(df, c(cols[col]))
    }
  }
  return (df)
}

dataframeFromJSONFile <- function(filename) {
  library(jsonlite)
  df <- jsonlite::fromJSON(paste(readLines(filename), collapse=""), simplifyDataFrame=T)
  df <- normalizeDataFrame(df)
  return (df)
}