How to set a locally-provided custom context with Ruby JSON-LD?

Question

I am getting accustomed to the Ruby RDF JSON-LD toolset and currently I'm trying to extract knowledge from plain JSON files which do not carry a JSON-LD context. Therefore I need a way to set a locally-provided context when loading them.

So what I am doing is using JSON::LD::API.toRdf. But it seems I can't set a local context directly in its interface. How can it be done?

Answer 1

The JSON-LD API (Spec and Ruby) describes a expandContext option. In Ruby, this can take a string (interpreted as a URL), a something that responds to #read (such as a StringIO or File), a Hash, Array, or an instance of JSON::LD::Context.

Typically, if you want to pass a locally-provided context, you can do so as a Hash. A common pattern I use is the following:

context = JSON.parse(%({
  "@context": {...}
}))

graph = RDF::Graph.new

JSON::LD::API.toRdf(input, context) { |statement| graph << statement}

Have a look at the documentation here, or feel free to find me on gitter.