useFileMetadata Hook

useFileMetadata hook is used to get the metadata of a file in Firebase Storage. A very simple example would be:

const reference = ref(storage, "path/to/remote/file.png");
const { dispatch } = useFileMetadata(reference);
const metadata = await dispatch();

Warning

useFileMetadata is lazy by default and will not do anything until you use dispatch function.

You can get the state of the progress with this example.

const { state } = useFileMetadata(reference);
const metadata = await dispatch();
// `state` is "ready" | "loading" | "done"

dispatch method will return an instance of FullMetadata, but additionally, you can also listen to metadata from useFileMetadata hook as well:

const { metadata } = useFileMetadata(reference);
// metadata updates and rerenders when the state is `"done"`
// until then, it is `undefined`
await dispatch();

Input Parameters

Input parameters for useFileMetadata hook is as follows:

Name	Type	Description	Required	Default Value
reference	firebase/storage/StorageReference	Reference to a file in Storage.	✅	-

Return Type

useFileMetadata hook returns an object with properties as below:

Name	Type	Description
metadata	FullMetadata or undefined	Metadata of file. undefined if the state is not "done".
state	"ready" | "loading" | "done"	The state of the process.
dispatch	() => Promise<FullMetadata>	A callback to start the process and return the metadata.