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Re: Schema Salad

From: David Booth <david@dbooth.org>
Date: Tue, 08 Sep 2015 13:04:09 -0400
Message-ID: <55EF1509.1030001@dbooth.org>
To: Peter Amstutz <peter.amstutz@curoverse.com>, public-linked-json@w3.org
CC: Eric Prud'hommeaux <eric@w3.org>
On 09/07/2015 09:33 PM, Peter Amstutz wrote:
> I wanted to introduce a project I am working on, "Schema Salad":
> https://github.com/common-workflow-language/schema_salad

Sounds very interesting!   You might want to look at Shape Expressions 
(ShEx) also, if you haven't seen it:
http://www.w3.org/2013/ShEx/Primer

ShEx is not JSON-specific, but can validate RDF or even transform it.

David Booth

>
> Salad is a schema language for describing structured linked data
> documents in JSON or YAML documents. A Salad schema provides rules for
> preprocessing, structural validation, and link checking for documents
> described by a Salad schema. Salad builds on JSON-LD and the Apache
> Avro data serialization system, and extends Avro with features for
> rich data modeling such as inheritance, template specialization,
> object identifiers, and object references. Salad was developed to
> provide a bridge between the record oriented data modeling supported
> by Apache Avro and the Semantic Web.
>
> The JSON data model is an extremely popular way to represent
> structured data. It is attractive because of it's relative simplicity
> and is a natural fit with the standard types of many programming
> languages. However, this simplicity means that basic JSON lacks
> expressive features useful for working with complex data structures
> and document formats, such as schemas, object references, and
> namespaces.
>
> JSON-LD is a W3C standard providing a way to describe how to interpret
> a JSON document as Linked Data by means of a "context". JSON-LD
> provides a powerful solution for representing object references and
> namespaces in JSON based on standard web URIs, but is not itself a
> schema language. Without a schema providing a well defined structure,
> it is difficult to process an arbitrary JSON-LD document as idiomatic
> JSON because there are many ways to express the same data that are
> logically equivalent but structurally distinct.
>
> Several schema languages exist for describing and validating JSON
> data, such as the Apache Avro data serialization system, however none
> understand linked data. As a result, to fully take advantage of
> JSON-LD to build the next generation of linked data applications, one
> must maintain separate JSON schema, JSON-LD context, RDF schema, and
> human documentation, despite significant overlap of content and
> obvious need for these documents to stay synchronized.
>
> Schema Salad is designed to address this gap. It provides a schema
> language and processing rules for describing structured JSON content
> permitting URI resolution and strict document validation. The schema
> language supports linked data through annotations that describe the
> linked data interpretation of the content, enables generation of
> JSON-LD context and RDF schema, and production of RDF triples by
> applying the JSON-LD context. The schema language also provides for
> robust support of inline documentation.
>
> This is a work in progress, and any comments, suggestions, or pointers
> to related/similar technologies would be very much appreciated.  Here
> are a couple of example schemas:
>
> https://github.com/common-workflow-language/schema_salad/blob/master/schema_salad/metaschema.yml
>
> https://github.com/common-workflow-language/common-workflow-language/blob/salad_schema/schemas/draft-3/cwl-avro.yml
>
> Thanks,
> Peter
>
>
>
>
Received on Tuesday, 8 September 2015 17:04:40 UTC

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