Promisekit: How to execute the same function in a loop

[hengchengfei]

I want to upload multiple images asynchronously.

how can I write it using PromiseKit?

let images:[UIImage]!

self.upload(image0).then {_ in
     self.upload(image1)
}.then {_ in
     self.upload(image2)
}.then {_ in
     self.upload(image3)
}
....
.then {image9 in
     self.upload(image9)
}

or

for image in images {
....
}

[mxcl]

when(fulfilled: images.map(upload)).then { results in
     //…
}

Or if for some reason you really want to do them serially:

var images = images
return Promise(value: ()).then { _ -> Promise<Void> in
    if let img = images.popFirst {
        return self.upload(img)
    } else {
        return Promise(value: ())
    }
}

However you should have good reason to not use when because it will be n times faster.

[hengchengfei]

@mxcl Thank you,I really appreciate.