Dynamic preferences

preferences may be a function. The hub calls it (inside the isolate, so every global helper works) with the values collected so far and renders whatever pages it returns. Combine it with submitOnChange on the inputs that should re-shape the form.

const preferences = (values) => ({
  pages: [
    {
      id: 'pick',
      title: 'What to control',
      inputs: [
        { key: 'domain', label: 'Device type', type: 'enum', submitOnChange: true, required: true,
          options: getActionDomains() },                               // from the hub's catalog
        { key: 'device', label: 'Device', type: 'entity', required: true,
          domainFilter: values.domain, visible: { input: 'domain', operator: 'truthy' } },
      ],
    },
    {
      id: 'action',
      title: 'Action',
      visible: { input: 'device', operator: 'truthy' },
      inputs: [
        { key: 'service', label: 'Do', type: 'enum', required: true, submitOnChange: true,
          options: getServicesForDomain(values.domain ?? '') },
        ...parameterInputs(values),
      ],
    },
  ],
});

function parameterInputs(values) {
  if (!values.domain || !values.service) return [];
  return getServiceParameters(values.domain, values.service).map((p) => ({
    key: `param_${p.key}`, label: p.label, type: p.type, required: p.required,
    minValue: p.min, maxValue: p.max, options: p.options, description: p.description,
  }));
}

What you can use insideCopy Anchor Link

• The catalog introspection functions, for domain, service and parameter pickers that stay in sync with the hub.
• new EntityWrapper(id).getAttributes() to enumerate a picked device's attributes (wrap in try/catch: the device may be offline at edit time).
• listSmartAppInstances() to offer other apps as options, getPlacePresenceOptions() for places, getHvacModeOptions() / getFanModeOptions() for thermostats.

Do not subscribe, schedule or call services from preferences; it runs during editing, not installation, and may run many times.

Keep stored values validCopy Anchor Link

The form engine drops an enum value that is missing from the current options. When options are computed from live data (an offline device returns no attributes), merge the stored value back in so a re-save does not silently clear the field.

Page flowCopy Anchor Link

Pages render in array order; a page whose visible condition is false is skipped. The wizard shows progress across the visible pages and lets people go back; going back and changing an answer re-runs your function with the new values.