data — Map reading
Read topics, notes, and resources from the approved map.
Table of content
Capability: data · Available in: live preview with an open map.
Main methods
| Method | Purpose |
|---|---|
this.data.getVirtualCollection({ dataType }) |
Open a Node, Note, or Resource collection |
collection.getAllEntities() |
Read topics; use targeted reads for notes and resources |
collection.getChildren(parentId) |
Read children of a topic or other parent |
collection.getEntityById(id) |
Read one entity in the approved map |
entity.getData() |
Read the entity snapshot |
entity.on(type, listener) / entity.off(type, listener) |
Observe or unsubscribe from entity changes |
collection.destroy() |
Release the collection and its handles |
const topics = await this.data.getVirtualCollection({ dataType: 'Node' });
const entities = await topics.getAllEntities();
const names = entities.map(topic => topic.name);
topics.destroy();
Capabilities
- Read topic names and properties, note block content, and resource metadata.
- Listen for
updated,created,deleted, or all (*) events. Collections also expose parent and global event subscriptions. - Use stable entity IDs to connect reads with map drawings.
Limits
Access is read-only and restricted to the approved map. Creating, updating, and deleting map entities through this API is not implemented. Supplying another map's ID does not expand access.
Reads are bounded to at most 200 entities per request and 250 retained entity handles per collection. Use getChildren() for larger maps and release handles when finished. Notes and resources generally require getChildren() or getEntityById() instead of getAllEntities().