'Returning object from promise function [duplicate]
I'm trying to return the list created with the value received from API to where it was called. I'm using Promise to make sure the function returns the value after it gets the value from calling API. To better explain with the code, I have a function callAPI that calls getNamedEntity. Ultimately, I want callAPI to receive the result of request.post() in getNamedEntity. However, I get Promise object and undefined when I test with console.log("outside " + result) and console.log("inside doRequest " + result) inside each function respectively.
function callAPI(text) {
const result = getNamedEntity(text);
console.log("outside " + result);
}
async function getNamedEntity(text) {
var requestJson = {
...
};
var options = {
...
};
function doRequest(options) {
return new Promise(function (resolve, reject) {
request.post(options, function (error, response, body) {
if (!error && response.statusCode == 200) {
const result = resolve(body);
console.log("inside doRequest " + result);
} else {
reject(error);
}
});
});
}
doRequest(options)
.then((body) => {
var entityList = [];
const obj = JSON.parse(body);
const words = obj.return_object.sentence[0].NE;
for (var word of words) {
entityList.push(word.text);
}
return entityList;
})
.catch((error) => {
console.log(error);
});
}
outside [object Promise]
inside doRequest undefined
Solution 1:[1]
console.log("outside " + result) returns a promise object cause you forgot to await the getNamedEntity(text); or, alternately, put the console.log inside a .then, like getNamedEntity(text).then(result => console.log(result));
console.log("inside doRequest " + result); returns undefined because the resolve function returns void, ie, it returns nothing. Change to console.log("inside doRequest " + body); or move the console.log into the .then((body) portion.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | Ron Newcomb |
