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Howto implement own serializiation format? [message #556621]

Thu, 02 September 2010 03:04

Eclipse User

Hi,

I've created a ecore model from a mdl file, created the corresponding gencore file and generated the code from the gencore file. While EMF has a own serialization mechanism based on XMI I want to support my project with a own serializiation mechanism. I've had a look on the EMF book as well as on the FAQ but I haven't found what I'm looking for. Maybe somebody can point me into the right direction or to the corresponding section in the documentation for my intents?

Thanks in advance!
Regards,
Michael

[Updated on: Thu, 02 September 2010 03:40] by Moderator

Re: Howto implement own serializiation format? [message #556644 is a reply to message #556621]

Thu, 02 September 2010 04:12

Eclipse User

You can define your own Resource system by implementing the Resource Interface. There, you can code your own loading/saving mechanism. You'll probably have to code your own resource factory that creates your resources and register that factory using the extension point org.eclipse.emf.ecore.extension_parser.

Re: Howto implement own serializiation format? [message #556647 is a reply to message #556644]

Thu, 02 September 2010 04:21

Eclipse User

Hi Michael

On 02/09/2010 09:12, Sylvain EVEILLARD wrote:
> You can define your own Resource system by implementing the Resource
> Interface. There, you can code your own loading/saving mechanism. You'll
> probably have to code your own resource factory that creates your
> resources and register that factory using the extension point
> org.eclipse.emf.ecore.extension_parser.

If you set the Package/Model/Resource Type to XMI in genmodel when you
first genmodel, you will get all the framework and registration created
automatically.

Then set Resource Type back to None and then rewrite XXXResourceImpl.

Regards

Ed Willink

Re: Howto implement own serializiation format? [message #556658 is a reply to message #556644]

Thu, 02 September 2010 04:48

Eclipse User

Am 02.09.2010 10:12, schrieb Sylvain EVEILLARD:
> You can define your own Resource system by implementing the Resource Interface.
Please note that the JavaDoc of the Resource interface says:

* Clients must extend the default {@link org.eclipse.emf.ecore.resource.impl.ResourceImpl implementation},
* or one of its derived classes, since methods can and will be added to this API.

Cheers
/Eike

Re: Howto implement own serializiation format? [message #556746 is a reply to message #556658]

Thu, 02 September 2010 09:53

Eclipse User

Yes, please don't directly implement the Resource interface. Extend
ResourceImpl and implement overrides for doSave and doLoad. You might
look at BinaryResourceImpl as an example of an alternative serialization.

Eike Stepper wrote:
> Am 02.09.2010 10:12, schrieb Sylvain EVEILLARD:
>> You can define your own Resource system by implementing the Resource
>> Interface.
> Please note that the JavaDoc of the Resource interface says:
>
> * Clients must extend the default {@link
> org.eclipse.emf.ecore.resource.impl.ResourceImpl implementation},
> * or one of its derived classes, since methods can and will be added
> to this API.
>
> Cheers
> /Eike

Re: Howto implement own serializiation format? [message #556773 is a reply to message #556621]

Thu, 02 September 2010 11:02

Eclipse User

Thank you all for your replies!

Regards,
Michael

Re: Howto implement own serializiation format? [message #558818 is a reply to message #556621]

Tue, 14 September 2010 10:21

Eclipse User

Hi,

I've tried to implement my own serialization format but I'm running into some trouble. I've got four projects which were generated from the genmodel.

- de.hs_rm.cs.vs.owl
- de.hs_rm.cs.vs.owl.edit
- de.hs_rm.cs.vs.owl.editor
- de.hs_rm.cs.vs.owl.tests

So far, I've done the following steps:

1. I've created a class OWLResourceFactoryImpl which implements Resource.Factory
2. Also I've created a class OWLResourceImpl which extends the ResourceImpl class and overwrites doSave and doLoad methods
3. I've added a extension point to de.hs_rm.cs.vs.owl plugin:

<extension point="org.eclipse.emf.ecore.extension_parser">
   <parser type="owl" class="owl.util.OWLResourceFactoryImpl">
</extension>

If I try to run the code I get a NoClassDefFoundError (the exception is caused while I'm calling the constructor of OWLResourceImpl in the OWLResourceFactoryImpl createResource method).

I've had a look on the EMF book and there is a description in the EMF Persistence API chapter (pages 457 and following). The book states that I should for stand alone applications add the following code:

Resource.Factory.Registry.INSTANCE.getExtensionToFactoryMap().put("owl", new OWLResourceFactoryImpl());

I'm not really sure where I should put the code. I've added the code in the createModel() method in the OWLEditor class in the de.hs_rm.cs.vs.owl.editor plugin but I'm not really sure that this is the right place. If I run the code as eclipse application I get still the NoClassDefFoundError Exception So probably that was not the right place to put the code.

Maybe somebody knows what I'm missing? Thanks in advance!
Michael

[Updated on: Tue, 14 September 2010 10:39] by Moderator

Re: Howto implement own serializiation format? [message #558825 is a reply to message #558818]

Tue, 14 September 2010 10:29

Eclipse User

Michael,

Comments below.

Michael Frey wrote:
> Hi,
>
> I've tried to implement my own serialization format but I'm running
> into some trouble. I've got four projects which were generated from
> the genmodel.
>
> - de.hs_rm.cs.vs.owl
> - de.hs_rm.cs.vs.owl.edit
> - de.hs_rm.cs.vs.owl.editor
> - de.hs_rm.cs.vs.owl.tests
>
> So far, I've done the following steps:
>
> 1. I've created a class OWLResourceFactoryImpl which implements
> Resource.Factory
> 2. Also I've created a class OWLResourceImpl which extends the
> ResourceImpl class and overwrites doSave and doLoad methods
> 3. I've added a extension point to de.hs_rm.cs.vs.owl plugin:
>
> <extension point="org.eclipse.emf.ecore.extension_parser">
> <parser type="owl" class="owl.util.OWLResourceFactoryImpl">
> </extension>
>
>
> If I try to run the code I get a NoClassDefFoundError if I try to call
> the constructor of OWLResourceImpl in the OWLResourceFactoryImpl
> createResource method.
That sounds more like a classpath issue. Is the util folder listed in
the bundle manifests's packages?
> I've had a look on the EMF book and there is a description in the EMF
> Persistence API chapter (pages 457 and following). The book states
> that I should for stand alone applications add the following code:
>
>
> Resource.Factory.Registry.INSTANCE.getExtensionToFactoryMap( ).put( "owl",
> new OWLResourceFactoryImpl());
>
>
> I'm not really sure where I should put the code.
Look at the XyzExample. java in the *.owl.tests project.
> I've added the code in the createModel() method in the OWLEditor class
> in the de.hs_rm.cs.vs.owl.editor plugin
The editor isn't stand alone though so no need for that.
> but I'm not really sure that this is the right place.
No.
> If I run the code as eclipse application I get an NullPointerException.
What's null?
> So probably that was not the right place to put the code.
>
> Maybe somebody knows what I'm missing? Thanks in advance!
Be sure the util package is an exported package.in the manifest.
> Michael

Re: Howto implement own serializiation format? [message #558829 is a reply to message #558825]

Tue, 14 September 2010 10:52

Eclipse User

Hi,