EGCL Validator

[gra-moore]

The Entity Constraint Language is used to model data structures but also serves and language to check data validity. Create a go module that can validate entities. Validation can be triggered in different ways. One would be as part of a Job. The validation is connected to an entity through the rdf:type property.

In the datahub schemas can be stored in datasets, or perhaps as files in the content storage if there is a need to work on complete works. A validation job should take a schema reference and an entity. The result should be a list of schema violations.

Processing wise, a job can choose to fail is validation fails or to write the entity further on with the validation information attached.

There are two separate tasks related to this:

1. Create standalone EGCL library that uses the EGDM library and can do validation and generate documentation
2. Add support in the datahub for trigger validation on a job or accessing the functionality from javascript