Sapply 函数中的多个 Google Places API 调用

Question

我有一个要输入 Google Places API 的位置列表。有些位置有超过 20 个结果。我在下面提供了一个此类位置的示例。要获得超过前 20 个的结果，您必须对 Google Places 进行额外的 API 调用，并使用从第一个 Google Places API 调用中获得的额外“令牌”参数。

使用以下有缺陷的函数，我试图根据是否需要获得额外的结果来执行额外的 API 调用。当前函数产生 NULL 值。任何有关纠正此功能的帮助将不胜感激。

要输入 Sapply 的列表：

LatLongList <- as.list("42.36354942,-71.06396087")

应用功能：

library(RCurl)
library(tidyjson)
library(magrittr)
library(dplyr)

PullFromPlaces <- function(x) {

  url = paste0("https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=",x,"&radius=",radius_meters,"&types=",type,"&key=",key)
    payload_json <- getURL(url)

    next_page_token <- payload_json %>%        
      as.tbl_json %>% 
      enter_object("next_page_token")
      next_page_token <- as.character(attr(next_page_token,"JSON"))

      if (length(next_page_token) != 0) {

      url = paste0("https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=",x,"&radius=",radius_meters,"&types=",type,"&pagetoken=",next_page_token,"&key=",key)
      payload_json <- getURL(url)

      }
}

应用执行：

Output <- sapply(LatLongList, PullFromPlaces)

Answer 1

我在vignette of my googleway package中有一个这样的查询示例

library(googleway)


api_key <- 'your_api_key'

myLocation <- c(42.36354942, -71.06396078)

myPlaces <- google_places(location = myLocation, 
                        radius = 500,
                        key = api_key)

nextPlaces <- google_places(location = myLocation,
                            radius = 500,
                            page_token = myPlaces$next_page_token, 
                            key = api_key)


myPlaces$results$name
# [1] "Boston"                                              "Kimpton Onyx Hotel"                                 
# [3] "Holiday Inn Express Hotel & Suites Boston Garden"    "Wyndham Boston Beacon Hill"                         
# [5] "The Boxer Boston Hotel"                              "Whole Foods Market"                                 
# [7] "The Liberty, a Luxury Collection Hotel, Boston"      "Massachusetts General Hospital"                     
# [9] "TD Garden"                                           "Sugarman, Rogers, Barshak & Cohen, P.C."            
# [11] "Dr. Richard J. Deasla, MD"                           "Massachussetts General Hospital"                    
# [13] "Massachusetts General Hospital: Temel Jennifer S MD" "Vrahas Mark Steven MD"                              
# [15] "Harry E. Rubash, MD"                                 "Dr. Ziv Williams, MD"                               
# [17] "CCRM Boston"                                         "Domino's Pizza"                                     
# [19] "Massachusetts General Hospital: Yeh Sunu Susan MD"   "North End"

nextPlaces$results$name
# [1] "Massachusetts General Hospital: Ryan Colleen MD"         "Warshaw Andrew L MD"                                    
# [3] "Massachusetts General Hospital: Althausen Anne M MD"     "Massachusetts General Hospital: Shipley William MD"     
# [5] "Massachusetts General Hospital: Feldman Adam S MD"       "Massachusetts General Hospital: Packard Swift Alison MD"
# [7] "Dr. Nahel Elias, MD"                                     "Dr. Steven L. Mcafee, MD"                               
# [9] "Dr. Charles A. Welch, MD"                                "Massachusetts General Hospital: Kilbride Ronan D MD"    
# [11] "Massachusetts General Hospital: Garasic Joseph Mich MD"  "Massachusetts General Hospital: Akins Cary W MD"        
# [13] "Dr. Edwin C. Huang, MD"                                  "Massachusetts General Hospital: Davis Benjamin T MD"    
# [15] "Massachusetts General Hospital: Levins Paul C MD"        "Massachusetts General Hospital: Passeri Jonathan MD"    
# [17] "Massachusetts General Hospital: Weil Michelle MD"        "Massachusetts General Hospital: Steele David John MD"   
# [19] "Massachusetts General Hospital: Chae Claudia U MD"       "Massachusetts General Hospital: Connolly Thomas Jose MD"

Answer 2

我想通了。下面是放入 sapply 或 lapply 的函数。半径、类型和关键参数是预定义的。

library(jsonlite)
library(RCurl)
library(tidyjson)
library(magrittr)
library(stringr)
library(plyr)
library(dplyr)

PullFromPlaces <- function(x) {

      url = paste0("https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=",x,"&radius=",radius_meters,"&types=",type,"&key=",key)
      payload_json <- getURL(url)

      next_page_token <- payload_json %>%        
        as.tbl_json %>% 
        enter_object("next_page_token") 
      next_page_token <- as.character(attr(next_page_token,"JSON"))

      if (length(next_page_token) == 0) {

        payload_json <- data.frame(payload_json,stringsAsFactors = FALSE)

      }   else {
        Sys.sleep(2)
        url2 = paste0("https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=",x,"&radius=",radius_meters,"&types=",type,"&pagetoken=",next_page_token,"&key=",key)
        payload_json2 <- getURL(url2)

        next_page_token <- payload_json2 %>%        
          as.tbl_json %>% 
          enter_object("next_page_token") 
        next_page_token <- as.character(attr(next_page_token,"JSON"))

        if (length(next_page_token) == 0) {

          payload_json <- rbind_pages(list(data.frame(payload_json,stringsAsFactors = FALSE),data.frame(payload_json2,stringsAsFactors = FALSE)))

        }   else {
          Sys.sleep(2)
          url3 = paste0("https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=",x,"&radius=",radius_meters,"&types=",type,"&pagetoken=",next_page_token,"&key=",key)
          payload_json3 <- getURL(url3)

          payload_json <- rbind_pages(list(data.frame(payload_json,stringsAsFactors = FALSE),data.frame(payload_json2,stringsAsFactors = FALSE),data.frame(payload_json3,stringsAsFactors = FALSE)))

        } 

      }
    }