Created
August 5, 2016 11:05
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Way to have cancelable promise
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// @flow | |
// https://facebook.github.io/react/blog/2015/12/16/ismounted-antipattern.html | |
export type CancelablePromise = { | |
promise: Promise<any>, | |
cancel: Function, | |
} | |
export const makeCancelablePromise = ( | |
promise: Promise<*> | |
): CancelablePromise => { | |
let hasCanceled = false | |
const wrappedPromise: any = new Promise((resolve, reject) => { | |
promise.then((val) => | |
hasCanceled ? reject({ isCanceled: true }) : resolve(val) | |
) | |
promise.catch((error) => | |
hasCanceled ? reject({ isCanceled: true }) : reject(error) | |
) | |
}) | |
return { | |
promise: wrappedPromise, | |
cancel(): void { | |
hasCanceled = true | |
}, | |
} | |
} | |
export const cancelableResolve = (data: any) : CancelablePromise => { | |
return makeCancelablePromise(Promise.resolve(data)) | |
} | |
export const cancelableReject = (data: any) : CancelablePromise => { | |
return makeCancelablePromise(Promise.resolve(data)) | |
} | |
export default ( | |
promise: Promise<any>, | |
resolve: (data: any) => void, | |
reject: (error: string) => void | |
): CancelablePromise => { | |
const cancelablePromise = makeCancelablePromise(promise) | |
cancelablePromise.promise | |
.then((response) => { | |
resolve(response.json) | |
}) | |
.catch((result) => { | |
const { isCanceled, error } = result | |
if (isCanceled) { | |
return | |
} | |
reject(error || result) | |
}) | |
return cancelablePromise | |
} |
Author
MoOx
commented
Aug 5, 2016
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