I'm having trouble updating a global variable in my Node app. Can someone look at my code and let me know what's going wrong? I've defined a dowhile loop to run as long as my HTTP response object does not have "next" defined. Inside the loop, things are running as expected and new_json.next is defined, but the while condition is returning an error because new_json.next is undefined there. I'm a little new at Javascript, so somehow my variable scope is off, but I can't figure out how to do things correctly based on other questions.
function make_pagination_request(json, create_response_data) {
var new_json={};
do {
var options = {
host: slug + '.nationbuilder.com', //should be replaced to be site-agnostic
path: json.next,
method: "GET",
json: true,
headers: {
"content-type": "application/json",
"accept": "application/json"
},
}
var req = https.get(options, req_callback);
function req_callback(response) {
response.on('data', function(chunk) {
str += chunk;
});
response.on('end', function(new_json) {
new_json=JSON.parse(str);
new_results = new_json.results
results= results.concat(new_results);
console.log("combinedlength: " + results.length)
console.log(new_json.next);
});
}
} while (new_json.next.includes("api"));
The problem is that the HTTPs request is asynchronous while the do/while cycle is synchronous. In this case the while statement is reached before a value containing next is assigned to the new_json variable.
When the while statement is reached the first time the callback function hasn't been called yet. Therefore the value of new_json is {} (the initial value) and it lack next. Therefore the error you are experiencing.
But the solution is not fixing the initial value of new_json. The solution is to remove the do/while loop and continue work inside the HTTPs request callback.
