Angular2: Returning Promise

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How do I convert an existing callback API to promises? 17 answers

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The AWS SDK for JavaScript has supported promises since version 2.3.0 released March 31st. Here's the annoucement.

I suggest you update to the latest SDK version if you are using something earlier than 2.3.0, and then use promises instead of callbacks.

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If you are using TypeScript you can do something like this to return a promise . I can imagine it would be around the same in the JavaScript style:

getBuckets() {
     return new Promise(function (resolve, reject) {
        var s3 = this.getS3();
        var params = {};
        s3.listBuckets(params, function(err, response) {
            if (err) {
                reject(err);
            }
            else {
                resolve(response);
            }
        })
     })
}

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You can use $q, documentatie here: https://docs.angularjs.org/api/ng/service/$q

That would look something like this:

getBuckets() {
    var deferred = $q.defer();
    var s3 = this.getS3();
    var params = {};
    s3.listBuckets(params, function(err, response) {
        if (err) {
            deferred.reject(err);
        }
        else {
            deferred.resolve(response);
        }
    })
    return deferred.promise;
}

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