Generate object model out of RelaxNG schema with RNGOM - how to start?

Question

I want to generate an object model out of an RelaxNG Schema.

Therefore I want to use the RNGOM Object Model/Parser (mainly because I could not find any alternative -

Answer 1

A way to proceed could be to :

1. use jing to convert from Relax NG to XML Schema (see here)
2. use more common tools to generate classes (e.g. JaxB).

Answer 2

Hi I ran into mostly the same requirement except I am concentrating on the Compact Syntax. Here is one way of doing what you want but YMMV.

To give some context, my goal in 2 phases: (a) Trying to slurp RelaxNG Compact Syntax and traverse an object/tree to create Spring 4 POJOs usable in Spring 4 Rest Controller. (b) From there I want to develop a request validator that uses the RNG Compact and automatically validates the request before Spring de-serializes the request. Basically scaffolding JSON REST API development using RelaxNG Compact Syntax as both design/documentation and JSON schema definition/validation.

For the first objective I thought about annotating the CompactSyntax with JJTree but I am obviously not fluent in JavaCC so I decided to go a more programatic approach...

I analyzed and tested the code in several ways to determine if there was a tree implementation in binary, digested and/or nc packages but I don't think there is one (an om/tree) as such.

So my latest, actually successful approach, has been to build upon binary and extend SchemaBuilderImpl, implement the visitor interface, and passing my custom SchemaBuilderImpl to CompactSyntax using the long constructor: CompactSyntax(CompactParseable parseable, Reader r, String sourceUri, SchemaBuilder sb, ErrorHandler eh, String inheritedNs)

When you call CompactParseable.parse you will get structured events in the visitor interface and I think this is good enough to traverse the rng schema and from here you could easily create an OM or tree.

But I am not sure this is the best approach. Maybe I missed something and there is in fact an OM/Tree built by the rngom implementation (in my case CompactSyntax) that you can traverse to determine parent/child relationships more easily. Or maybe there are other approaches to this.

Anyway, this is one approach that seems to be working for what I want. Is mostly visitor pattern based and since the interfaces were there I decided to use them. Maybe it will work for you. Bottom line, I could not find an OM/AST that can be traversed implemented anywhere in the implementation packages (nc, binary, digested).