Thank you for the quick reply - I'll look into the
XMLBookmark idea...
Is there anything else I need to know about the preSet and
postSet methods? I found documentation (including the operationType
values) at http://dev2dev.bea.com/pub/a/2004/11/Configuring_XMLBeans.html -
is this the latest-and-greatest, or is there a better and/or more current
reference available?
Tim From: Cezar Andrei [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 28, 2006 2:29 PM To: user@xmlbeans.apache.org Subject: RE: alternate representations of collections in XMLBeans?? Tim, I would recommend using
the extensions, otherwise modifying the generated code is definitely possible
but missing even a small thing would break the
code. Back to using
extensions, if one wants to store a state he can do it by using XmlBookmark –
which stays with the xml entity even if moved. In your case the hash map should
be stored on ‘metadata’ element. Also the pre/post Set
methods are called every time the document is about to change, so you’ll get
calls for all creation/modification/deletion events, made through XmlObject
interfaces. Modification through other interfaces like XmlCursor or DOM will not
trigger the calls to the pre/post Set methods. Cezar From: Tim
Parker [mailto:[EMAIL PROTECTED] The XMLBeans representation of a
collection (for something with a maxOccurs GT 1) is a bit limiting... I'm
looking to extend it to look more like a Map interface... and I'm hitting some
brick walls... For discussion sake, I'll use a
structure with three fields: struct
foo { int
ID; String
name; HashMap
metadata; } The 'metadata' field contains
arbitrary name/value pairs - for simplicity we'll say 'name' and 'value' fields
in the hashmap are always strings... The obvious (to me, at
least) schema for this is something
like: <xs:complexType
name="NVP"> <xs:complexType
name="NVPCollection"> <xs:complexType
name="testCase">
<xs:sequence> <xs:element
name="ID" type="xs:int"/> <xs:element
name="name" type="xs:string"/> <xs:element
name="metadata" type="my:NVPCollection"/>
</xs:sequence> </xs:complexType> ==== I could build another layer on top
of this, but this could get ugly - What I really need is a way to
extend NVPCollection so I can address items by name (like in a HashMap) rather
than by position... The ideal would be something like
(assuming that we have a mechanism to bind the 'name' field to the map key and
the 'value' field to be the one of
interest)... NVPCollection
thisCollection; // some magic here to get the
collection populated... someValue =
thisCollection.GetByMap("someArbitraryName"); .... Or we could save some binding
complexity by doing ...GetByMap("someArbitraryName","value"), saying "get the
field 'value' from the collection member whose key field contains
'someArbitraryName'" (The presumption is that the binding to the key field
'name' would need to be established earlier so the map can be
maintained) ==== As I read the documentation, I could
build an extension like this, but I'm hosed if I want to do anything more
sophisticated than a linear search through the collection on each 'get' call -
Unless I'm missing something, I need a place to put an instance-specific HashMap
object to maintain mapping between the key field ('name') and the array index...
more than a little difficult with the 'static method' requirement for the
extension (Not to mention the population problem for the HashMap object
itself, but a preSet or postSet implementation would work as long as I never try
to delete anything).. Presumably I could also build an
'extendedNVPCollection' class, based on the NVPCollection class generated by
XMLBeans, but how would I wire that back into my (XMLBeans-generated) 'testCase'
class? I don't want to get into creating wrapper classes for every
layer... I tried ignoring the "don't
touch - generated code" warnings and added some stuff directly to the
generated classes for the NVPCollection object, but things started
breaking - I'm not sure if the problem is a flaw in my hacking or a
fundamental problem I won't solve, so I'm seeking advice - am I tilting at
windmills here? Does anyone have ideas as to better
ways to do this? =======================================================
Tim
Parker ===================
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- alternate representations of collections in XMLBeans?? Tim Parker
- RE: alternate representations of collections in XMLBeans... Cezar Andrei
- RE: alternate representations of collections in XMLBeans... Tim Parker
- RE: alternate representations of collections in XMLBeans... Cezar Andrei