R/top_rising_search.R

In PMassicotte/gtrendsR: Perform and Display Google Trends Queries

#' Extract top and rising searches
#'
#' @param data Data returned by a search query.
#'
#' @return A list with TOP and RISING data (if such data was found).
extract_top_rising <- function(data) {
  
  start_top <- which(grepl("TOP", data))[1]
  start_rising <- which(grepl("RISING", data))[1]
  
  if (length(start_top) == 0 & length(start_rising) == 0) {
    return(NULL) ## No data returned
  }
  
  if (is.na(start_top) & is.na(start_rising)) {
    return(NULL) ## No data returned
  }
  
  new_res <- NULL
  
  if (length(start_top) > 0) {
    end_top <- ifelse(length(start_rising) == 0, length(data), start_rising - 2)
    
    # Make sure there are "RISING" data. If not, use the length of the vector
    # and the end index.
    
    if (is.na(end_top)) {end_top = length(data)}
    
    top <- read.csv(textConnection(data[start_top:end_top]),
                    row.names = NULL, encoding = "UTF-8"
    )
    top$subject <- rownames(top)
    rownames(top) <- NULL
    top <- top[, c(2, 1)]
    names(top) <- c("subject", "top")
    
    top <- reshape(
      top,
      varying = "top",
      v.names = "value",
      direction = "long",
      timevar = "related_topics",
      times = "top"
    )
    
    new_res <- rbind(new_res, top)
  }
  
  # Make sure there are "RISING" data.
  
  if (length(start_rising) > 0 & !is.na(start_rising)) {
    rising <- read.csv(textConnection(data[start_rising:length(data)]),
                       row.names = NULL, encoding = "UTF-8"
    )
    rising$subject <- rownames(rising)
    rownames(rising) <- NULL
    rising <- rising[, c(2, 1)]
    names(rising) <- c("subject", "rising")
    
    rising <- reshape(
      rising,
      varying = "rising",
      v.names = "value",
      direction = "long",
      timevar = "related_topics",
      times = "rising"
    )
    
    new_res <- rbind(new_res, rising)
  }
  
  return(new_res)
}