将ebay Feed API与R结合使用

Question

[我正在尝试使用R调用ebay Feed API，但不了解所使用的语法，似乎我在API调用中缺少标题：

> res <- GET(paste0("https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216"))
> res
Response [https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216]
  Date: 2019-12-21 08:39
  Status: 400
  Content-Type: application/json
  Size: 228 B
{
  "errors" : [ {
    "errorId" : 1002,
    "domain" : "OAuth",
    "category" : "REQUEST",
    "message" : "Missing access token",
    "longMessage" : "Access token is missing in the Authorization HTTP request header."
  } 

标题应该在哪里？我已经看到了类似的事情，添加了参数，这会正确吗？ payload是不同身份验证元素的列表：

res_bis <- GET("https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216", authenticate() = payload, encode = "form", verbose())

非常感谢！

EDIT1：我看到了有关HTTP标头的信息：

HTTP请求标头：Content-Type –必须设置发送至：application / x-www-form-urlencoded授权-“基本”一词”，然后是您的Base64编码的OAuth凭据（client_id：client_secret）。

然后我尝试了以下操作，但仍然出现相同的错误：

 GET("https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216", add_headers("Basic client_id:client_secret"))

EDIT2：在Andrea的帮助下更新我的代码：

> GET("https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216", 
+     add_headers(client_id = paste0("Basic", " ",your_token)), content_type("application/x-www-form-urlencoded")  )

Response [https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216]
  Date: 2019-12-21 12:17
  Status: 400
  Content-Type: application/json
  Size: 228 B
{
  "errors" : [ {
    "errorId" : 1002,
    "domain" : "OAuth",
    "category" : "REQUEST",
    "message" : "Missing access token",
    "longMessage" : "Access token is missing in the Authorization HTTP request header."
  } ]
> 

EDIT3：多亏了Andrea，我设法获得了access token：

但是我仍然会遇到相同的错误：

your_token= "XXXXXXXXX"
GET("https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216", add_headers(client_id = paste0("Basic", " ",your_token)), content_type("application/x-www-form-urlencoded")  )

Response [https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216]
  Date: 2019-12-22 17:56
  Status: 400
  Content-Type: application/json
  Size: 228 B
{
  "errors" : [ {
    "errorId" : 1002,
    "domain" : "OAuth",
    "category" : "REQUEST",
    "message" : "Missing access token",
    "longMessage" : "Access token is missing in the Authorization HTTP request header."
  } ]

Answer 1

感谢您的耐心安德里亚，您的最后建议似乎正在奏效！好吧，我没有得到预期的数据（从Ebay获得了403状态代码错误，而从Ebay API得到了很多空字段），但是在调查之后，我认为这与我的Ebay应用尚未得到Ebay授权有关。希望我能写这篇文章，谢谢您的宝贵时间！

Answer 2

基于上述交流，主要问题是对ebay feed api auth flows的理解不足。首先，必须获取一个Authorization令牌来认证将来的api请求。

library(httr)
library(jsonify)

api_token <- "your_token_string"

# Get authorization token
auth_token_res <- GET("https://api.sandbox.ebay.com/identity/v1/oauth2/token",
                      add_headers(client_id = paste0("Basic", " ",api_token)),
                      content_type("application/x-www-form-urlencoded")) %>% 
  fromJSON()

access_token <- auth_token_res[["access_token"]]  # parse it from JSON resp

该令牌将像以前一样在以后的呼叫中以add_headers()传递：

# Make request
feed_res <- GET("https://api.ebay.com/buy/feed/v1_beta/item?feed_scope=ALL_ACTIVE&category_id=625&date=20191216",
                add_headers(Authorization = paste0("Bearer", " ",access_token)))

# ... parse fields as needed from JSON  response