Summary: DOMRequest is an API that we implemented before DOM promises were available, and it is superseded by Promise. It is, however, incompatible with the Promise API in three main ways: its API surface is completely different, it uses DOM events to dispatch success/error events, and its events are dispatched synchronously. Currently DOMRequest is used by a lot of APIs on Firefox OS.
We would like to start the process of transitioning some of these APIs to use Promises. As a first step to ease the migration pass, I'm implementing a DOMRequest.then() method which is compatible with Promise.then(), and is intended to be a drop-in replacement. DOMRequest.then() returns a Promise, and calls its resolve or reject callbacks asynchronously. The returned promise can be chained with other Promises in the usual way. Our hope is that with this implemented, we are able to treat the DOMRequest objects returned from the APIs above as Promises by calling .then() on them. This will hopefully enable us to make those APIs return a Promise in the future without breaking the code that uses them. It will also help the consumers of those APIs to be able to use Promises throughout their code without having to worry about DOMRequest. Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=839838 Link to standard: DOMRequest is a Mozilla specific API that has no corresponding standard. Platform coverage: everywhere. Estimated or target release: Firefox 35, Firefox OS 2.2. Preference behind which this will be implemented: The patch is quite simple, and the implementation is done using Promise internally, which is a shipped and well-tested feature, so I don't think it's worth hiding this one method behind a preference. Note that once the patch is reviewed, I plan to land it on trunk, enabled by default. Cheers, -- Ehsan _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
