LDhop - Follow Your Nose Through Linked Data Resources

Start with a resource, and then follow your nose through the Knowledge graph, discover and fetch new resources, and keep following your nose

Also, it's possible to update and re-fetch one of the resources, and everything else will get adjusted accordingly.

Concept

We have a RDF store at the center. We specify how we want to walk through the knowledge graph. When we arrive at a new resource, we fetch it, and continue the walk through it.

When resource is added or changed, we check whether there was anything new in that resource. If yes, we replace the old resource with the new one; and trickle the dependencies further.

Query

Read here

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

[1.0.0-alpha.8] - 2026-01-10

Fixed

• core - Fix type inference in concat (LdhopQueryBuilder).

[1.0.0-alpha.7] - 2026-01-10

Changed

• core - Keep track of starting point types S in LdhopQueryBuilder<V, S>

[1.0.0-alpha.6] - 2026-01-10

Added

• react - Allow globally configuring the React Query key via configureQueryKey. Export DEFAULT_QUERY_KEY.
• core - Add a query builder.
• react - useLdhopQuery also accepts LdhopQueryBuilder.

[1.0.0-alpha.5] - 2025-12-30

Changed

• core - Generalize type of input variables to Iterable.

Removed

• core - Remove some unused types.

[1.0.0-alpha.4] - 2025-12-29

Added

• core, react - Support variables without ? as starting points. This API may change before v1.0.
• core - Add method getAllPlainVariables to LdhopEngine to get the result variables without ?. This API may change before v1.0.
• core - Add a helper method getVariableNames(query) that returns set of all variables within a LdhopQuery.

Changed

• react - BREAKING CHANGE - Result variables in useLdhopQuery are plain variables. This API may change before v1.0.

[1.0.0-alpha.3] - 2025-12-25

Added

• core - Export additional types.
• core - Add onQuadsChanged callback to LdhopEngine.
• react - Implement useLdhopQuery hook.

Deprecated

• react - useLDhopQuery is deprecated in favour of useLdhopQuery and will be removed in version 1.0.

[1.0.0-alpha.2] - 2025-12-21

Fixed

• core - Use response url as baseIRI in fetchRdfDocument, to handle relative IRIs correctly when there is a redirect.

[1.0.0-alpha.1] - 2025-11-30

Added

• core - Implement LdhopEngine callbacks.

[1.0.0-alpha.0] - 2025-08-24

Added

• core - Implement new LdhopEngine API.
• core - Detect and remove orphaned cycles.
• core - Track resource redirects in graph management.

Deprecated

• core - QueryAndStore is deprecated in favor of LdhopEngine (will be removed in version 1.0).
• core - Type RdfQuery is deprecated in favor of LdhopQuery.

[0.1.1] - 2025-02-19

Fixed

• core: Send Accept header with supported mime-types when fetching a resource.
• example-react: Recreate yarn.lock to get rid of @tanstack/react-query duplicate.

[0.1.0] - 2025-01-25

Fixed

• core: Fix incorrect move in hop logic when variable is other than subject. [d453752eebf07c83e633634a8477bcc1483ba5a0]
• core: Add missing error to failed request in run helper. [d453752eebf07c83e633634a8477bcc1483ba5a0]

Documentation

• Start using Conventional Commits.
• Add this changelog following Keep a Changelog. [ff9716f1cc93437f18e7916560f885acea41dc6a]

[0.0.1-alpha.16] - 2024-10-02

Added

• All changes until this point