The Vault
This is the main library used to fetch, store and retrieve IIIF resources. It is not tied to a single framework and can be used with both JavaScript and Typescript.
Fetching a manifest
Presumably the first thing that any IIIF-library needs to be able to do is fetch a IIIF manifest given a URL. In Hyperion it's quite simple.
import { Vault } from '@hyperion-framework/vault';
const vault = new Vault();
vault.loadManifest('https://.../manifest.json').then(manifest => {
// we have our manifest here.
})
What this returns is a promiset that when resolved will be a IIIF manifest from the store. Here's a demo of this in action, with a simple manifest being fetched and then a logo extracted and displayed. If you click open in editor you will be able to get auto-complete on the manifest and explore some of the properties.
The key thing to remember is the references. The manifest is always flat so items that are related to it are referenced by type and ID. The manifest is also always Presentation 3 regardless of what the source is. So when you are requesting properties from the manifest, they may not match the original source. For example, the manifest above has a manifest.description field on it. Since the semantics of this has changed in Presentation 3, this property has moved to the manifest.metadata property instead, with a label of description.
Getting data from your manifest
Now that we've got resources loaded, lets look at a few ways of getting the data you want to display out of the framework.
Flat Earth
As previously mentioned, when a manifest or collection is loaded into Vault it is first normalized. The benefits of this described in the normalization section come with the additional overhead for querying your manifest. If you want to get a canvas from a manifest for example, you will need to "dereference" it using vault.fromRef(). As you go further down the chain from manfiest, to canvas, to annotation page, to annotation and finally to annotation body the benefits of using normalized data seem to be for nothing!
Luckily there are ways to simplify all of this referencing, by splitting out our code into refined selectors.