To be quite honest, the simplest most immediate change would be to simply allow access to the OptionalAttributes.
For me this would be sufficient. For adding attributes via MetaTypeProvider, one could simply create a felix.metatype annotation which is placed on OCDs and ADs passed from one's MetaTypeProvider impl. - Ray On Tue, Mar 3, 2015 at 3:03 PM, Raymond Auge <raymond.a...@liferay.com> wrote: > I would like to revive this thread. > > I have a need for the same thing, and for precisely the same reason as > Alexander! > > I also don't mind the proposed interface, however I have less need for > supporting many namespaces as I believe that at least one specific to > modeling the UI is really the key here. > > But the last suggestion would be fine to me! > > However, I do agree that no solution is complete without supporting > MetaTypeProviders. I'll investigate the options there and see if I can > propose something. > > - Ray > > > On Fri, Jan 18, 2013 at 3:42 AM, <alexander.ber...@finnova.ch> wrote: > >> Hi >> >> Wakeup-Call :-). Has anybody a better idea or substantial arguments >> against my last proposal? >> >> Regards, >> Alex >> >> -----Ursprüngliche Nachricht----- >> Von: alexander.ber...@finnova.ch [mailto:alexander.ber...@finnova.ch] >> Gesendet: Montag, 14. Januar 2013 10:59 >> An: dev@felix.apache.org >> Betreff: AW: Metatype Service - OptionalAttributes - extra XML attributes >> with namespace support >> >> Bridging the world of namespace-aware XML and not namespace-aware object >> models like Java, where an object can only have one field (attribute) with >> the same name, is quite difficult. In other words if we allow for multiple >> namespaces for XML attributes (which at the moment is the case according to >> the spec) then we must also adopt that concept of namespaces in the Java >> object model. >> >> And as a note, (namespace) prefixes by them self are meaningless. They >> only convey meaning if they are associated with a namespace. >> >> So we need a solution which is namespace-aware and not limited to, but >> compatible to XML. In the light of this I suggest the following interface, >> where "namespace" is now a generic concept (abstraction) and does not >> necessarily stand for XML-namespaces per se. >> >> public interface ExtraAttributes { >> >> /** >> * List the names of extra attributes for a given namespace. >> * >> * @param namespace the namespace for which to retrieve the names >> of available attribute. >> * >> * @return an {@link Iterator} producing the {@link String}s of >> the extra attribute names. >> * for the given namespace. >> */ >> public Iterator<String> getExtraAttributeNames(String namespace); >> >> /** >> * Retrieve the value of an extra attribute. >> * >> * @param namespace the namespace from which to retrieve the >> attribute value. >> * @param name name of the extra attribute, whose value should be >> retrieved. >> * @return the value of the extra attribute or <code>null</code> >> if no attribute with >> * that name exists. >> */ >> public String getExtraAttributeValue(String namespace, String >> name); } >> >> What do you think. >> >> Regards >> Alex >> >> -- >> finnova AG Bankware >> Alexander Berger >> Software Architect >> Merkurstrasse 6 >> CH-5600 Lenzburg >> Tel: +41 (0)62 886 48 07 (direkt) >> Tel: +41 (0)62 886 47 47 (zentrale) >> Fax: +41 (0)62 886 48 88 >> mailto:alexander.ber...@finnova.ch >> http://www.finnova.ch >> >> >> -----Ursprüngliche Nachricht----- >> Von: Felix Meschberger [mailto:fmesc...@adobe.com] >> Gesendet: Montag, 14. Januar 2013 10:39 >> An: dev@felix.apache.org >> Betreff: Re: Metatype Service - OptionalAttributes - extra XML attributes >> with namespace support >> >> Hi >> >> QNAme is an XML-ism and the API is XML-free (as I said, use of XML is >> just one way to back the API). So I am extremely reluctant to using QName >> (regardless of whether we use javax.xml.QName or define our own QName >> class). Always consider the case where an QbjectClassDefinition might be >> backed by a MetaTypeProvider service and not XML. >> >> As for the interface (except QName question), I am fine. >> >> However, I could assume we could have the name, if it comes from XML, to >> be something like >> >> {url}localname >> >> or >> >> prefix:localname >> >> And, of course, the {url} or prefix: prefix would be omitted for the >> default namespace (empty string) or the namespace of the metatype >> descriptor. >> >> Regards >> Felix >> >> Am 14.01.2013 um 07:43 schrieb <alexander.ber...@finnova.ch> < >> alexander.ber...@finnova.ch>: >> >> > O.K. I see. >> > >> > Then I would suggest to add something like the following interface to >> AttributeDefinition and ObjectClassDefinition: >> > >> > public interface ExtraAttributes { >> > >> > /** >> > * List the {@link QName}s of extra XML attributes. >> > * >> > * @return an {@link Iterator} producing the {@link QName}s of >> the extra attributes. >> > */ >> > public Iterator<QName> getExtraAttributeNames(); >> > >> > /** >> > * Retrieve the value of an extra XML attribute. >> > * >> > * @param name {@link QName} of the extra attribute, whose value >> should be retrieved. >> > * @return the value of the extra attribute or <code>null</code> >> if no attribute with >> > * that name exists. >> > */ >> > public String getExtraAttributeValue(QName name); } >> > >> > However, my initial question about QName and XML API support arises >> > again as we are using QName here. Note, using just a String as >> > argument to getExtraAttributeValue will not work, as several >> > attributes with the same name but different Namespaces (prefixes) might >> exist on the same Element. >> > >> > Regards >> > Alex >> > >> > -- >> > finnova AG Bankware >> > Alexander Berger >> > Software Architect >> > Merkurstrasse 6 >> > CH-5600 Lenzburg >> > Tel: +41 (0)62 886 48 07 (direkt) >> > Tel: +41 (0)62 886 47 47 (zentrale) >> > Fax: +41 (0)62 886 48 88 >> > mailto:alexander.ber...@finnova.ch >> > http://www.finnova.ch >> > >> > -----Ursprüngliche Nachricht----- >> > Von: Felix Meschberger [mailto:fmesc...@adobe.com] >> > Gesendet: Samstag, 12. Januar 2013 22:15 >> > An: dev@felix.apache.org >> > Betreff: Re: Metatype Service - OptionalAttributes - extra XML >> > attributes with namespace support >> > >> > >> > Am 10.01.2013 um 17:14 schrieb <alexander.ber...@finnova.ch> < >> alexander.ber...@finnova.ch>: >> > >> >> That's a good question. >> >> >> >> I think in terms of an API for accessing extra XML attributes, >> >> chances are good that such an API could be standardized (at least >> >> technically). But in terms of the specific "extra XML attributes" I >> >> see no way to get them standardized. And I guess that is the reason >> >> why the XSD (XML Schema) for the metatype descriptions allows for >> extra attributes (which reside in another XML namespace). Maybe someone >> that has worked on the specification might clarify what the intention about >> allowing the extra attributes was. >> > >> > Originally the idea was, that the same XML files would be used for >> metatype descriptors and other applications. Which is why it is lenient to >> other data. >> > >> >> >> >> Unless I know more about the matter I long for the following: >> >> >> >> 1. Anybody can enrich the metatype descriptions with his own >> (specific/individual) metadata. >> >> The current specification supports this by allowing extra XML >> attributes that reside in another namespace (##other). >> >> >> >> 2. An API to list respectively retrieve those extra attributes. And >> ideally such an API could become part of the >> >> metatype specification (new methods on the already existing >> interfaces or on new sub-interfaces). >> > >> > Please also consider that XML files are only one source for metatype >> descriptors. Access is always through API which can also be implemented >> without having XML. >> > >> > One option I could conceive, though, would be that we extend the >> AttributeDefinition interface with a new method: >> > >> > String getExtraAttribute(String name); >> > >> > which returns the named attribute. >> > >> > WDYT ? >> > >> > Regards >> > Felix >> > >> > >> >> >> >> Regards >> >> Alex >> >> >> >> >> >> -----Ursprüngliche Nachricht----- >> >> Von: Felix Meschberger [mailto:fmesc...@adobe.com] >> >> Gesendet: Donnerstag, 10. Januar 2013 15:58 >> >> An: dev@felix.apache.org >> >> Betreff: Re: Metatype Service - OptionalAttributes - extra XML >> >> attributes with namespace support >> >> >> >> Hi Alex, >> >> >> >> Sorry, I missed your message from last week. >> >> >> >> Am 10.01.2013 um 13:34 schrieb <alexander.ber...@finnova.ch> < >> alexander.ber...@finnova.ch>: >> >> >> >>> I want to add some extra attributes to the metadata (XML) which will >> then be used by a (special) administration console which knows about that >> extra attributes. These extra attributes will be used to allow a more >> concise representation of Configurations in the Graphical User Interface >> (GUI). For example to show a value from a certain configuration property >> instead of its PID in the GUI, as PIDs are quite meaningless to the average >> User. >> >> >> >> Thanks. The reason for asking is, whether your use case is in fact >> something that could be generalized to properly enhance the API. And thus >> to try to get it into the specification. >> >> >> >> Do you think such a generalization might be possible ? >> >> >> >> Regards >> >> Felix >> >> >> >>> >> >>> Regards >> >>> Alex >> >>> >> >>> -- >> >>> finnova AG Bankware >> >>> Alexander Berger >> >>> Interface Development >> >>> Merkurstrasse 6 >> >>> CH-5600 Lenzburg >> >>> Tel: +41 (0)62 886 48 07 (direkt) >> >>> Tel: +41 (0)62 886 47 47 (zentrale) >> >>> Fax: +41 (0)62 886 48 88 >> >>> mailto:alexander.ber...@finnova.ch >> >>> http://www.finnova.ch >> >>> >> >>> -----Ursprüngliche Nachricht----- >> >>> Von: Felix Meschberger [mailto:fmesc...@adobe.com] >> >>> Gesendet: Freitag, 4. Januar 2013 14:41 >> >>> An: dev@felix.apache.org >> >>> Betreff: Re: Metatype Service - OptionalAttributes - extra XML >> >>> attributes with namespace support >> >>> >> >>> Hi, >> >>> >> >>> Am 04.01.2013 um 08:23 schrieb <alexander.ber...@finnova.ch> < >> alexander.ber...@finnova.ch>: >> >>> >> >>>> Hi >> >>>> >> >>>> I intend to use extra (optional) XML attributes with the Metatype >> Service. >> >>> >> >>> Before commenting in detail, I would be interested to know what >> exactly you want to achieve by using additional attributes on object class >> and attribute definitions. >> >>> >> >>> Regards >> >>> Felix >> >>> >> >>> >> >>>> For this purpose I examined the >> >>>> Felix metatype service implementation and found the class >> >>>> org.apache.felix.metatype.OptionalAttributes, >> >>>> which is extended by AD, OCD, ... . But unluckily this class is >> >>>> neither inherited by LocalizedObjectClassDefinition nor by >> LocalizedAttributeDefinition, which makes it quite useless for the moment. >> >>>> >> >>>> Another Problem is that OptionalAttributes does not support XML >> namespaces for the attribute names. >> >>>> The underlying Map should use something like >> >>>> javax.xml.namespace.QName as key and not just the name of the >> >>>> attribute (String). Note, XML namespace support is crucial as extra >> XML attribute have to be in a different (##other) namespace (see "Metatype >> Service Specifiaction" (Version 1.2), section 105.9 "XML Schema"). >> >>>> >> >>>> The above observations lead me to the following question: >> >>>> >> >>>> 1. Is it still a requirement for Felix subprojects to avoid >> dependencies on packages like java.xml.** and rely on kxml2 instead? >> >>>> a. If so, then I could try create a patch for metatype service >> which will add support for extra XML attributes (including XML namespace >> support but not using javax.xml.namespace.QName), >> >>>> so that extra XML attributes could be retrieved from AD, >> OCD, ..., LocalizedObjectClassDefinition and LocalizedAttributeDefinition >> instances. >> >>>> b. If not, then I could try to create a similar patch as >> described above (a) but using javax.xml.namespace.QName instead. >> >>>> >> >>>> Note, the class javax.xml.namespace.QName is part of JavaSE since >> version 1.5 older versions as well as JavaME do not contain that class. >> >>>> >> >>>> Alex >> >>>> >> >>>> >> >>> >> >> >> > >> >> > > > -- > *Raymond Augé* <http://www.liferay.com/web/raymond.auge/profile> > (@rotty3000) > Senior Software Architect *Liferay, Inc.* <http://www.liferay.com> > (@Liferay) > Board Member & EEG Co-Chair, OSGi Alliance <http://osgi.org> > (@OSGiAlliance) > -- *Raymond Augé* <http://www.liferay.com/web/raymond.auge/profile> (@rotty3000) Senior Software Architect *Liferay, Inc.* <http://www.liferay.com> (@Liferay) Board Member & EEG Co-Chair, OSGi Alliance <http://osgi.org> (@OSGiAlliance)
