R/GetDeepSearchResults.R

In sptrsn/IDX: IDX Real Estate

#' Get the 'Deep Search' results from the Zillow API
#'
#' For a given address, extract property information including building data and Zestimates.
#' At least one of zipcode or city/state information must be included.
#'
#' @name GetDeepSearchResults
#' @param address (required) A character string specifying the address
#' @param city An optional character string specifying the city name
#' @param state An optional character string specifying the state name (abbreviated length 2)
#' @param zipcode An optional character or numeric string of length 5 specifying the zip code
#' @param api_key (required) A unique character string specifying the Zillow user's API key
#' @export
#' @importFrom rvest html_text
#' @importFrom assertthat assert_that
#' @importFrom dplyr bind_rows
#' @importFrom stringr str_replace
#' @importFrom utils URLencode
#' @importFrom tibble as_tibble
#' @import magrittr
#' @import xml2
#' @return If \code{raw=T}, the XML document directly from the API call. If \code{raw=F} (default), a data frame with columns corresponding to address information, Zestimates, and property information. The number of columns varies by property use type.
#' @examples
#' \dontrun{zapi_key = getOption('ZillowR-zws_id')}
#'
#' \dontrun{
#'
#' GetDeepSearchResults(address='600 S. Quail Ct.', zipcode='67114',
#'  api_key=zapi_key)
#'
#'  }
#'
#' \dontrun{GetDeepSearchResults(address='312 Hayward Ave.', city='Ames', state='IA',
#'   zipcode='50014', api_key=zapi_key) }
#'




GetDeepSearchResults <- function(address, city=NULL, state=NULL, zipcode=NULL, api_key=null,raw=FALSE){
  assertthat::assert_that(is.character(address),
                          (!is.null(zipcode)|(!is.null(city)&(!is.null(state)))),
                          msg='Error: Invalid address/city/zip combo')
  assertthat::assert_that(is.character(api_key), msg='invalid api key')

  url = 'http://www.zillow.com/webservice/GetDeepSearchResults.htm'
  #parse address to url encoding
  address_as_url <- URLencode(address)
  #parse city names with spaces in them
  cityspace <- city %>% str_replace(" ","-")
  citystatezip = paste0(cityspace,if(!is.null(city)){','}, state,if(!is.null(state)){','},zipcode)

  request <- url_encode_request(url,
      'address' = address,
      'citystatezip' = citystatezip,
      'rentzestimate' = TRUE,
      'zws-id' = api_key
  )
  #read data from API then get to the nodes
  xmlresult <- read_xml(request)
  if(raw==TRUE){
   return(xmlresult)
  }
  xmlresult<- xmlresult %>%
    xml_nodes('result')

  if(length(xmlresult) == 0){

    return(0)

  }else{

    # # address data
    address_data <- xmlresult %>% lapply(extract_address_search) %>%  lapply(as.data.frame.list)
    address_data<-data.frame(address_data)
    addnames<-c("address","zipcode","city","state","lat","long","region_name","region_id","type")
    address_data<-address_data[,addnames]

    #return(address_data)

    # # other property data
    richprop <- xmlresult %>% extract_otherdata_search

    if(nrow(richprop)>1){
      richprop<-richprop %>% filter(str_length(zpid)==9 & is.numeric(zpid))
    }
    if(nrow(richprop)==0){
      richprop[1,] <- NA
    }
    #return(data.frame(richprop))

    # # zestimate data
    zestimate_data <- xmlresult %>% lapply(extract_zestimates) %>% lapply(as.data.frame.list)
    zdf<-data.frame(zestimate_data)
    if(nrow(zdf)==0){
      zdf[1,] <- NA
    }
    zestcolselect<-c("zestimate","zest_lastupdated","zest_monthlychange","zest_percentile","zestimate_low","zestimate_high")
    zestimate_data<-zdf[, zestcolselect]

    # # rentzestimate data
    rent_zestimate_data <- xmlresult %>% lapply(extract_rent_zestimates) %>% lapply(as.data.frame.list)

    if(length(rent_zestimate_data)>1){
      rent_zestimate_data<-rent_zestimate_data[1]
    }
    rentdf<-data.frame(rent_zestimate_data)

    use<-c("rentzestimate","rent_lastupdated","rent_monthlychange","rentzestimate_low","rentzestimate_high")

    rentdf<-rentdf[, use]

    if(nrow(rentdf)==0){



      rentdf[1,] <- data.frame(list(NA,NA,NA,NA,NA))

    }

    # # combine all of the data into 1 data frame
    outdf <- data.frame(address_data,richprop,zestimate_data,rentdf)

    return(outdf)

  }

}


#address_data <- suppressWarnings(bind_rows(address_data))
#zestimate_data <- suppressWarnings(bind_rows(zestimate_data))
#rent_zestimate_data <- suppressWarnings(bind_rows(rent_zestimate_data))