Fetch all the items from a StorageMap

[lrazovic]

Feature Request

I have the following FRAME Storage Item: A StorageMap with an id as key and a struct as a value.

#[pallet::storage]
#[pallet::getter(fn projects)]
pub type Projects<T: Config> =
    StorageMap<_, Blake2_128Concat, T::ProjectIdentifier, ProjectOf<T>>;

It's very easy to fetch a single value using Capi:

const result = await Funding.Projects.entry([project_identifier]).run()

On polkadot.js you can also omit the key and get back all the content of the storage item. e.g.

I'm trying to replicate the same behaviour using Capi, without success. I tried:

const assets = await Assets.Asset.entry([]).run()

but the parameter of the entry(...) method should be a [number] | Rune<[number], never>.

I also tried

const assets = await Assets.Asset.entry([] as any).run()

But I'm getting undefined as result.

It would be very useful to be able to fetch an unknown quantity of elements as is done on polkadot.js, perhaps even implementing some kind of pagination. I am available for further details or necessary tests.

[harrysolovay]

The ability to retrieve the entire map could be a foot gun. In the interest of explicit control over the retrieval size, we'll opt for a StorageRune entryPage method to complement keyPage. This will be complemented by #567.