Undefined Error when parsing JSON in google apps script

Question

I'm trying to parse JSON I recieved from an API call, but I keep running into the error "TypeError: Cannot read property "id" from undefined. (line 42, file "")" I'm relatively new to Apps Script. Any ideas on what's going on? I can get the payload back in JSON, but can't seem to parse it.

function getInfo() {
    var url = "https://subdomain.chargify.com/subscriptions.json";
    var username = "xxx"
    var password = "x"

    var headers = {
        "Authorization": "Basic " + Utilities.base64Encode(username + ':' + password)
    };

    var options = {
        "method": "GET",
        "contentType": "application/json",
        "headers": headers
    };

    var response = UrlFetchApp.fetch(url, options);
    var data = JSON.parse(response.getContentText());
    Logger.log(data);

    var id = data.subscription; // kicks back an error
    // var id = data;    works and returns the whole JSON payload

    var ss = SpreadsheetApp.getActiveSheet()
    var targetCell = ss.setActiveSelection("A1");
    targetCell.setValue(id);
}

Answer 1

According to the documentation here https://docs.chargify.com/api-subscriptions#api-usage-json-subscriptions-list

it returns an array of subscriptions when you call the /subscriptions.json endpoint. So probably your data object should be handled like:

for (var i=0;i<data.length;i++) {
var item = data[i]; //subscription object, where item.subscription probably works
Logger.log(JSON.stringify(item));
}

Answer 2

function getInfo() {
    var url = "https://subdomain.chargify.com/subscriptions.json";

    var username = "xxx"
    var password = "x"

    var headers = {
        "Authorization": "Basic " + Utilities.base64Encode(username + ':' + password)
    };

    var options = {
        "method": "GET",
        "contentType": "application/json",
        "headers": headers
    };

    var response = UrlFetchApp.fetch(url, options);
    var data = JSON.parse(response.getContentText());

    for (var i = 0; i < data.length; i++) {
        var item = data[i]; //subscription object, where item.subscription probably works
        Logger.log(JSON.stringify(item));
        var subscriptionid = item.subscription.id;
    }

    var ss = SpreadsheetApp.getActiveSheet()
    var targetCell = ss.setActiveSelection("A2");
    targetCell.setValue(subscriptionid);
}