Constructing the UrlFetchApp request to obtain an Access Token from ChinaBrands API - api

Question

function getAccessToken()
{
var url = "https://gloapi.chinabrands.com/v2/user/login";
var data = {
"email": EMAILID,
"password": PWD,
"client_id": APIKEY
}
var payload = {
"data": data,
"signature": Utilities.base64Encode(data + SECRETKEY)
}
var options = {
"method": "post",
"contentType": "application/json",
"payload": payload
};
var json = UrlFetchApp.fetch(url, options).getContentText();
Browser.msgBox(json);
}
Please see attached documentation API screenshot link below.
I am trying to connect ChinaBrands API using google apps script.
I am getting error which says "{"status":0,"msg":"Requested info is empty","errcode":10006}"
See this Image : Documentation API to get AccessToken:

Answer 1

The documentation is a bit misleading. You need to make POST request with Content-Type: application/x-www-form-urlencoded. The request data field should be a string with your data in JSON format. I guess depending on language/libraries you use, you might need to URL encode the JSON data before making the request.
The resulting request should look like:
POST https://gloapi.chinabrands.com/v2/user/login
...
Accept: */*
Content-Type: application/x-www-form-urlencoded
signature=<md5 of string containing data in json + client secret>&data=%7B%22email%22%3A+%22name%40example.com%22%2C+%22password%22%3A+%2222password1%22%2C+%22client_id%22%3A+%1337%22%7D
Python 3 example with requests library:
url = "https://gloapi.chinabrands.com/v2/user/login"
data = {...}
json_data = json.dumps(data)
signature = md5((json_data + client_secret).encode('utf')).hexdigest()
response = requests.post(url, data={'signature': signature, 'data': json_data})