Merge branch '22-r-skript-fur-birthplace-erstellen' into 'master'

Resolve "R-Skript für Birthplace erstellen"

Closes #22

See merge request !22

r/GetBirthplace.R

+#!/usr/bin/env Rscript
+
+# Author: Lukas
+
+## librarys
+
+library(rvest)
+library(stringr)
+library(data.table)
+
+#' This script extracts Birthplace from physicist texts
+#' Try to get the infobox and extract the birthplace
+#' If there is no infobox, 0 will be returned as 
+#' birthplace is hard to extract from text
+#' 
+#' @param article Article in HTML-format
+#' @return String with birthplace of the physicist|0
+getBirthplace <- function(article) {
+  
+  # If there is no infobox we return 0
+  if(!grepl("vcard", article)) {
+      return(0)
+  }
+  
+  # Use infobox to get Birthplace
+  infoBox <- getInfoBox(article)
+  
+  # Get 'Born' field
+  birthplace <- infoBox[infoBox$Desc %like% "Born",]$Content
+  
+  # Remove everything in front of the "\n"
+  # Rest is birthplace
+  birthplace <- gsub(".*\\\n", "", birthplace)
+  
+  # return birthplace
+  return(birthplace)
+}
+
+### Converts info box to table
+getInfoBox <- function(article) {
+  # Read page as html
+  page <- read_html(article)
+  
+  # Extracting text from the html will erase all <br> tags,
+  # this will replace them with line breaks
+  
+  xml_find_all(page, ".//br") %>%
+    xml_add_sibling("p", "\n")
+  
+  xml_find_all(page, ".//br") %>%
+    xml_remove()
+  
+  # Get the info box
+  # Will throw an error if there isnt any, so that should be checked beforehand
+  
+  table <- page %>%
+    html_nodes("table.vcard") %>%
+    html_table(fill = TRUE) %>%
+    .[[1]]
+  
+  colnames(table) <- c("Desc", "Content")
+  
+  return(table)
+}