The following contexts were removed or renamed during the course of the IE.
Discussions at the Southampton TC showed that the proposed elf-basic and elf-preview contexts were muddled and tried to do too many things:
As the IE is primarily about linking features and enabling discovery of data we agreed to switch focus of the core ELFIE contexts to the indexing/discoverability use case. This is best implemented using schema.org. elf-basic and elf-preview can be replaced with the schema.org context file. (We’ll only use a small subset of keys - those associated with a Thing or Place).
Issue 53 removed elf-basic and elf-preview and added the link to the schema.org context to relevant contexts and example documents.
There is a GeoJSON-LD vocabulary and we thought it would be interesting to extend the GeoJSON-LD context to identify ELFIE properties that can be discovered in the GeoJSON properties object. The context is simple, it just imports all the ELFIE view contexts (elf-all.jsonld).
As it is just a convenience document, there’s nothing to stop a service provider individually referencing the specific ELFIE contexts as appropriate.
The example file (xample-elf-geojson.json) is valid according to the GeoJSONLint validator.
Ultimately this experiment was abandoned as GeoJSON geometries are not legal JSON-LD objects. See ‘Outstanding issues’ in the GeoJSON JSON-LD vocabulary proposal.
| VIEW | CONTEXT FILE | EXAMPLE | COMMENT | | —- | ———— | ——- | ——- | | eld-all | elf-all.jsonld | xample-elf-all.json | An all components context that imports everything for when you just want to say everything you know. Necessary? Even more importantly - is this legitimate? | | elf-basic | elf-basic.jsonld | | rdfs:type from elf-basic maps on to JSON-LD’s @type keyword. | | elf-geojson | elf-geojson.jsonld | xample-elf-geojson.json | See ‘Experiment - ELFIE GeoJSON-LD’ above. Imports http://geojson.org/geojson-ld/geojson-context.jsonld | | elf-index | elf-index.jsonld | xample-elf-index.json | Core properties of each feature that support discovery/indexing. Each domain specific JSON file should include these. | | elf-net-basic | elf-net-basic.jsonld | xample-elf-net-basic.json | | | elf-net-spatial | elf-net-spatial.jsonld | xample-elf-net-spatial.json | Imports elf-net-basic.jsonld. Deliberately dropped ‘sf’ prefix from keyword names to reinforce the fact we recommend picking and sticking with one topology model. (Discuss?) | | elf-net-temporal | elf-net-temporal.jsonld | xample-elf-net-temporal.json | Imports elf-net-basic.jsonld. | | elf-net | elf-net.jsonld | | Imports elf-net-basic.jsonld, elf-net-spatial.jsonld, elf-net-temporal.jsonld | | elf-preview | elf-preview.jsonld | | | elf-sosa | | | Based on the O&M ttl examples introduced in Annex C.10 of SOSA specification. Restricted to O&M sampling features for simplicity’s sake (no sensor descriptions etc). Split into a context per feature type for clarity. Possibly no real need? | | elf-sosa-sample | elf-sosa-sample.jsonld | | Context for Samples - in our case sampling features such as monitoring stations, boreholes etc. | | | | xample-elf-sosa-sample.json | Example with multiple observations inline - used the @graph key as all objects in the array share the same context. | | | | xample-elf-sosa-sample-byref.json | As above, but observations by reference. | | | | xample-elf-sosa-sample-preview.json | Monitoring station using only preview and simple relationship keys. | | elf-sosa-observation | elf-sosa-observation.jsonld | xample-elf-sosa-observation.json | Context for Observations. |
Context and example files are published in the docs folder and can be referred to at the path
https://opengeospatial.github.io/ELFIE/json-ld/deprecated.
For example: https://opengeospatial.github.io/ELFIE/json-ld/deprecated/elf-geojson.jsonld