How to send a JSON payload with UrlFetchApp service? - json

Question

I'm trying to POST to a web service that is expecting to get JSON as payload using Google Apps Script. I'm using the following code:
var options =
{
"method" : "post",
"contentType" : "application/json",
"headers" : {
"Authorization" : "Basic <Base64 of user:password>"
},
"payload" : { "endDate": "2012-06-03" }
};
var response = UrlFetchApp.fetch("http://www.example.com/service/expecting/json", options);
On the server side I'm getting the following error:
WARN [facade.SettingsServlet] 04 Jun 2012 15:30:26 - Unable to parse request body: endDate=2012-06-03
net.liftweb.json.JsonParser$ParseException: unknown token e
I'm assuming that the server is expecting to get
{ "endDate": "2012-06-03" }
instead of
endDate=2012-06-03
but I don't know how to make the UrlFetchApp do it.

Answer 1

I do not understand the server side error but the 'payload' parameter must be a string as specified here: https://developers.google.com/apps-script/class_urlfetchapp?hl=fr-FR#fetch.
try:
var options =
{
"method" : "post",
"contentType" : "application/json",
"headers" : {
"Authorization" : "Basic <Base64 of user:password>"
},
"payload" : '{ "endDate": "2012-06-03" }'
};

Answer 2

If you set payload as a String, it will be passed directly (as a
UTF-8 string).
If you set payload as an Object, it will be sent like
an HTML form (which means either 'application/x-www-form-urlencoded' if the
fields are simple, or 'multipart/form-data' if the Object includes a
blob/file).
For your use case (the server is expecting to receive JSON), it sounds like Utilities.jsonStringify() is the way to go.

Answer 3

Something like this worked for me in a similar situation:
Instead of creating payload and adding to options, I built the parameters into a string to append to the URL:
var params = "id=2179853&price=62755";
then, I appended params to the url string:
var result = UrlFetchApp.getRequest(url + '?' + params, options);
So, my options was passed containing only the header.
For my project, this worked like a charm.

Answer 4

Here goes the code that should work with some important comments:
function testMe() {
var products_authkey = "------------";
try {
var url = "https://app.ecwid.com/api/v1/---------/product?id=----------&secure_auth_key=" + products_authkey;
//url= "http://requestb.in/----------"; // you can actually debug what you send out with PUTs or POSTs using Requestb.in service
var payload = {
id: "21798583", // id is necessary and should be a string, or it might be sent in scientific representation (with E)
price: 62755
};
payload = JSON.stringify(payload); // the payload needs to be sent as a string, so we need this
var options = {
method: "put",
contentType: "application/json", // contentType property was mistyped as ContentType - case matters
payload: payload
};
var result = UrlFetchApp.getRequest(url, options);
Logger.log(result) // a better way to debug
var result = UrlFetchApp.fetch(url, options); // works perfectly in my case
Logger.log(result)
} catch (e) {
Logger.log(e)
}
}