Version 1.53.92
- Technology preview of a GNOME 3.32 feature: native Promises for GIO-style
asynchronous operations. This is the result of Avi Zajac's summer internship.
To use it, you can opt in once for each specific asynchronous method, by
including code such as the following:
Gio._promisify(Gio.InputStream.prototype, 'read_bytes_async',
'read_bytes_finish');
After executing this, you will be able to use native Promises with the
Gio.InputStream.prototype.read_async() method, simply by not passing a
callback to it:
try {
let bytes = await stream.read_bytes_async(count, priority, cancel);
} catch (e) {
logError(e, 'Failed to read bytes');
}
Note that any "success" boolean return values are deleted from the array of
return values from the async method. That is,
let [contents, etag] = file.load_contents_async(cancel);
whereas the callback version still returns a useless [ok, contents, etag]
that can never be false, since on false an exception would be thrown. In the
callback version, we must keep this for compatibility reasons.
Note that due to a bug in GJS (https://gitlab.gnome.org/GNOME/gjs/issues/189),
promisifying methods on Gio.File.prototype and other interface prototypes will
not work. We provide the API Gio._LocalFilePrototype on which you can
promisify methods that will work on Gio.File instances on the local disk only:
Gio._promisify(Gio._LocalFilePrototype, 'load_contents_async',
'load_contents_finish');
We estimate this will cover many common use cases.
Since this is a technology preview, we do not guarantee API stability with
the version coming in GNOME 3.32. These APIs are marked with underscores to
emphasize that they are not stable yet. Use them at your own risk.
- Closed bugs and merge requests:
* Added promisify to GJS GIO overrides [!225, Avi Zajac]
* Temporary fix for Gio.File.prototype [!226, Avi Zajac]