[Feature]provide a way to cancel a fetch request

[SuBeibei]

I sent a request using fetch in "componentDidMount", then I try to cancel it in "componentWillUnmount".But I didn't find a way to do it.I notice that in Android NetworkingModule provides method "abortRequest".

[facebook-github-bot]

Hey SuBeibei, thanks for reporting this issue!

React Native, as you've probably heard, is getting really popular and truth is we're getting a bit overwhelmed by the activity surrounding it. There are just too many issues for us to manage properly.

• If you don't know how to do something or something is not working as you expect but not sure it's a bug, please ask on StackOverflow with the tag react-native or for more real time interactions, ask on Discord in the #react-native channel.
• If this is a feature request or a bug that you would like to be fixed, please report it on Product Pains. It has a ranking feature that lets us focus on the most important issues the community is experiencing.
• We welcome clear issues and PRs that are ready for in-depth discussion. Please provide screenshots where appropriate and always mention the version of React Native you're using. Thank you for your contributions!

[satya164]

fetch doesn't have a way to cancel the request as per the Promise spec. You can use XMLHttpRequest directly if you need to cancel the request.

[hfossli]

I would love to see this reopened.

[superandrew213]

@hfossli use https://github.com/apentle/react-native-cancelable-fetch

[ssssssssssss]

Shall we reopen this for the AbortController? http://mo.github.io/2017/07/24/abort-fetch-abortcontroller-polyfill.html

[ahmadalfy]

fetch is now cancellable via AbortController

The final version of AbortController has been added to the DOM specification
The corresponding PR for the fetch specification is now merged.