The question was:
How do I return the response from an asynchronous call?
which can be interpreted as:
How to make asynchronous code look synchronous?
The solution will be to avoid callbacks, and use a combination of Promises and async/await.
I would like to give an example for an Ajax request.
(Although it can be written in JavaScript, I prefer to write it in Python, and compile it to JavaScript using Transcrypt. It will be clear enough.)
Let’s first enable jQuery usage, to have $ available as S:
__pragma__ ('alias', 'S', '$')Define a function which returns a Promise, in this case an Ajax call:
def read(url: str): deferred = S.Deferred() S.ajax({'type': "POST", 'url': url, 'data': { },'success': lambda d: deferred.resolve(d),'error': lambda e: deferred.reject(e) }) return deferred.promise()Use the asynchronous code as if it were synchronous:
async def readALot(): try: result1 = await read("url_1") result2 = await read("url_2") except Exception: console.warn("Reading a lot failed")