vitessce-add-coordination-to-view

name	vitessce-add-coordination-to-view
description	Use when wiring an existing coordination type into an existing Vitessce subscriber component — making a view read or write a piece of shared state it doesn't currently use. Trigger on "add coordination to a view", "wire up coordination", "make this view respond to a new property", "subscribe to a coordination type", "add a coordination scope to a view", or "link this view to shared state".

Adding a Coordination Type to an Existing View

This covers the case where the coordination type already exists and you're connecting it to a view that doesn't currently use it. To register a brand-new coordination type, see vitessce-add-coordination-type first.

1. Update COMPONENT_COORDINATION_TYPES

In packages/constants-internal/src/coordination.ts, add the type to the view's array:

export const COMPONENT_COORDINATION_TYPES = {
  [ViewType.MY_VIEW]: [
    CoordinationType.OBS_TYPE,       // existing
    CoordinationType.MY_NEW_TYPE,    // add this
  ],
};

This is the most commonly missed step. useCoordination only returns the parameters it is passed, and every subscriber passes COMPONENT_COORDINATION_TYPES[ViewType.MY_VIEW] — so if the type isn't listed here it will come back undefined.

2. Destructure in useCoordination

In the subscriber component, add the new value and setter:

const coordinationScopes = useCoordinationScopes(coordinationScopesRaw);

const [{
  obsType,
  myNewType,        // add
}, {
  setObsType,
  setMyNewType,     // add setter if the view should be able to change this value
}] = useCoordination(COMPONENT_COORDINATION_TYPES[ViewType.MY_VIEW], coordinationScopes);

Setter names are derived mechanically as set + capitalized parameter name, so no registration is needed for the setter itself.

Note that coordinationScopes must be the output of useCoordinationScopes(coordinationScopesRaw), not the raw prop — that hook resolves metaCoordinationScopes indirection.

3. Pass to the child component

<MyView
  obsType={obsType}
  myNewType={myNewType}
  setMyNewType={setMyNewType}
/>

4. Update the view config

Add the coordination scope to any layout entries that use this view, and declare its value in coordinationSpace:

coordinationSpace: {
  // ...existing...
  myNewType: { A: defaultValue },
},
layout: [
  {
    component: 'myView',
    coordinationScopes: {
      obsType: 'A',
      myNewType: 'A',   // add
    },
    ...
  },
],

With initStrategy: 'auto' you can omit this — Vitessce will auto-assign a scope holding the coordination type's registered default value — but explicit is clearer when you want a specific initial value.

Per-layer / per-channel coordination

If the coordination type is scoped per layer or per channel (as in the spatial and layer-controller views), the values live in coordinationScopesBy rather than coordinationScopes, and the subscriber reads them via useCoordinationScopesBy plus the multi-level variants in packages/vit-s/src/state/hooks.js (e.g. useMultiCoordinationScopes, useMultiCoordinationScopesSecondary) instead of a plain useCoordination call. Follow the pattern in packages/view-types/spatial-beta/src/SpatialSubscriber.js for that case.