R/gGeoCode2.r

In ivanhanigan/gisviz: GIS visualisation and data manipulation tools

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# name:gGeoCode2

getDocNodeVal <- function(doc, path){
  sapply(getNodeSet(doc, path), function(el) xmlValue(el))
}

gGeoCode2 <- function(str, first=T){  
  if(!is.data.frame(str) & length(str) == 1)
  {
    str2 <- gsub(' ','%20',str)
    u <- sprintf('https://maps.googleapis.com/maps/api/geocode/xml?sensor=false&address=%s',str2)
    xml.response <- getURL(u, ssl.verifypeer=FALSE)
    
    doc <- xmlTreeParse(xml.response, useInternal=TRUE, asText=TRUE)
    
    
    
    lat <- getDocNodeVal(doc, '/GeocodeResponse/result/geometry/location/lat')
    lng <- getDocNodeVal(doc, '/GeocodeResponse/result/geometry/location/lng')
    if(length(lng) == 1 & first == F){
      
      out <- c(str, lng, lat)
    } else if(length(lng) >= 1 & first == T) {
      out<-c(str, lng[1], lat[1])
    } else {
      out<-c(str, NA, NA)
    }
    out<-as.data.frame(t(out))
  } else {
    
    if(is.data.frame(str)){
      if(ncol(str) == 1)
        {
          str <- as.character(str[,1])
        } else {
      stop("only character vectors or singlecolumn dataframes allowed")
      }
    }
    
    pointTable<-as.data.frame(matrix(nrow=0, ncol=3))
    for(index in 1: length(str))
    {
      #index <- 1
      str2 <- gsub(' ','%20',str[index])

      u <- sprintf('https://maps.googleapis.com/maps/api/geocode/xml?sensor=false&address=%s',str2)
      xml.response <- getURL(u, ssl.verifypeer=FALSE)
      
      doc <- xmlTreeParse(xml.response, useInternal=TRUE, asText=TRUE)
      
      
      
      lat <- getDocNodeVal(doc, '/GeocodeResponse/result/geometry/location/lat')
      lng <- getDocNodeVal(doc, '/GeocodeResponse/result/geometry/location/lng')
      
      if(length(lng) == 1 & first == F){
        
        out <- c(str[index], lng, lat)
      } else if(length(lng) >= 1 & first == T) {
        out<-c(str[index], lng[1], lat[1])
      } else {
        out<-c(str[index], NA, NA)
      }
      pointTable<-rbind(pointTable,as.data.frame(t(out)))
    }
    #names(pointTable)<-c('Location', 'Latitude', 'Longitude')
    out <- pointTable
  }

  names(out) <- c('address','long','lat')
  out$long <- as.numeric(as.character(out$long))
  out$lat <- as.numeric(as.character(out$lat))
  
  return(out)
  
}