jsonld-cpp

JSON-LD Implementation for C++

This is a C++ implementation of JSON-LD 1.1 Processing Algorithms and API (http://json-ld.org)

Development is still in progress--this library currently only supports the expand() and toRdf() processing algorithms.

Implementation Notes

Some parts of the JSON-LD API spec make note of using Promises to return API results. This C++ library does not support any Promise-like capability.

The RemoteDocument implementation currently only supports local files, not documents from arbitrary URLs.

Building jsonld-cpp

To build jsonld-cpp, you will need:

• cmake
• g++, clang or Visual Studio (community edition)

jsonld-cpp uses http-link-header-cpp and includes it as a submodule. When cloning, use git clone --recursive to include the submodule.

jsonld-cpp uses a pretty standard cmake build system:

mkdir build
cd build
cmake ..
make

You can also run all the tests:

make test

Installing prerequisites

If the above doesn't work, you probably need to install some prerequisites. For example, on a fresh Debian 12 ("bookworm") system:

$ sudo apt update
$ sudo apt install make cmake g++ libssl-dev

Now you can again try to build jsonld-cpp.

Examples

The examples directory contains a simple application called jsonld2rdf that shows how to interface with the library. It can convert a JSON-LD document into RDF data in NQuads format. As part of the conversion to RDF, the JSON-LD document is first expanded.

$ cd jsonld-cpp/build
$ ./jsonld-cpp-examples-prefix/src/jsonld-cpp-examples-build/jsonld2rdf examples/ex01a.jsonld
<http://example.com/people/dave> <http://xmlns.com/foaf/0.1/knows> <http://example.com/people/markus> .
<http://example.com/people/dave> <http://xmlns.com/foaf/0.1/name> "Dave Longley" .
<http://example.com/people/gregg> <http://xmlns.com/foaf/0.1/knows> <http://example.com/people/markus> .
<http://example.com/people/gregg> <http://xmlns.com/foaf/0.1/name> "Gregg Kellogg" .
<http://example.com/people/markus> <http://xmlns.com/foaf/0.1/name> "Markus Lanthaler" .