Choice between bindings and episodes?

[buko]

I have a dependency on a project 'A'.

A defines custom bindings in an .xjb file.

I would like to use the dependency A as both a source of bindings and as an episode file.

It seems like I can't do that.

If I depend on A purely as an episode then everything works but A's bindings are lost. The result is classes are generated with properties in the native JAXB types (eg XMLGregorianCalendar).

If I depend on A purely as a binding then A's bindings get picked up but A's classes will be re-generated into my target/generated-sources/xjc directory.

If I try to depend on A as both a binding and an episode then I get nasty errors of the form:

com.sun.istack.SAXParseException2; systemId: maven:com.bubblegumproject.uia.schema:uia-datatypes-schema-binding:jar::!/xml/bindings/uia-datatypes.xjb; lineNumber: 11; columnNumber: 24; Multiple are defined for the target namespace "urn:schemas-uia:datatypes"

[ERROR] Error while parsing schema(s).Location [ jar:file:/C:/Users/ocean/.m2/repository/com/bubblegumproject/uia/schema/uia-datatypes-schema-binding/0.0.1-SNAPSHOT/uia-datatypes-schema-binding-0.0.1-SNAPSHOT.jar!/META-INF/sun-jaxb.episode{19,74}].
com.sun.istack.SAXParseException2; systemId: jar:file:/C:/Users/ocean/.m2/repository/com/bubblegumproject/uia/schema/uia-datatypes-schema-binding/0.0.1-SNAPSHOT/uia-datatypes-schema-binding-0.0.1-SNAPSHOT.jar!/META-INF/sun-jaxb.episode; lineNumber: 19; columnNumber: 74; Another is defined here

So it finds the binding in the xjb file and then it finds another bindings in the sun-jaxb.episode and it blows up.

Am I doing something wrong?

Is it not okay to have a dependency that provides custom bindings and acts as an episode dependency?

(This is all open source so I can provide links if necessary.)

[buko]

After doing some digging:

1. No, it's not okay to include both bindings and episodes. Episodes are bindings. They map elements directly to previously generated classes. This is why you get all those nasty multipleSchemaBinding errors if you include both.

2. I was under the impression that I could define a simpleType and an XMLAdapter in Schema A and then have schema B depend on schema A as an episode|binding. Schema B would then use that simpleType on attributes and what not and it would automatically pick up the XMLAdapter from Schema A's xjb file. This is apparently not possible. xjb files can't be reused. Just episodes and catalogs. So Schema B has to create new bindings that set the XMLAdapter wherever A's simpleType is used.

3. It may be possible to do this with globalBindings. A globalBindings that knows about all simpleType<=>XMLAdapter mappings could in theory be re-used across several projects. I'll dig into that possibility next. Though this won't actually lead to really modular schema compilation it would prevent endless repetitive bindings.

[highsource]

1. Correct, episodes are essentially bindings but it does not mean you can't use episodes with bindings. Check ogc-schemas/filter/2.0, project for instance. It uses ows-v_1_1_0 as episode via dependency and also uses two binding files.

2. Essentially yes, you can reuse bindings of the schema A. I don't think, however that this will work via episodes as I think XJC does not generate XMLAdapter for simpleTypes in episodes (but I might be wrong here). However I don't see any problem reusing the binding file from A. Normally if you put your binding file in src/main/resources, this will be packaged in the target JAR. With dependencyResource you can reference binding files as resources in JARs so that should be no big problem. A useful trick is to compile schemas from an absolute URL + use a catalog file to rewrite URLs to local resources.

3. Really modular schema compilation is somewhat hard. It took me huge effort to implement this in the ogc-schemas project but it is possible.