glorp problem - DictionaryMapping

Hi,

I am a glorp newbie and to learn something about it I tried the  
examples from the tutorial of Roger Whitney. All works fine but the  
DictionaryMapping example does not.
I get an error with the following descriptor:

descriptorForAddressBook: aDescriptor
        | table linkTable |
        table := self tableNamed: 'ADDRESS_BOOK'.
        linkTable := self tableNamed: 'ADDRESS_BOOK_LINKS'.
        aDescriptor table: table.
        aDescriptor
                addMapping: (DirectMapping from: #id to: (table fieldNamed: 'id')).
        aDescriptor
                addMapping: (DirectMapping from: #title to: (table fieldNamed:  
'title')).
        aDescriptor addMapping: ((DictionaryMapping new)
                                attributeName: #entries;
                                referenceClass: Person;
                                keyField: (linkTable fieldNamed: 'person_key');
                                relevantLinkTableFields: (Array with: (linkTable fieldNamed:  
'person_id')))

An error happens because the descriptor variable of DictionaryMapping  
is nil (s. top of stack below). I cannot figure out what is the cause.
Any help?

Johannes


Unhandled exception: Message not understood: #system
UndefinedObject(Object)>>doesNotUnderstand:
Glorp.DictionaryMapping(Glorp.Mapping)>>system
Glorp.DictionaryMapping>>associationDescriptor
Glorp.DictionaryMapping>>newMapping:
Glorp.DictionaryMapping>>keyField:
GlorpTutorialDescriptor>>descriptorForAddressBook:
GlorpTutorialDescriptor(Glorp.DescriptorSystem)>>initializeDescriptor:
optimized [] in Glorp.DescriptorSystem>>descriptorFor:
Dictionary>>at:ifAbsent:
GlorpTutorialDescriptor(Glorp.DescriptorSystem)>>descriptorFor:
optimized [] in Glorp.DescriptorSystem>>allDescriptors
optimized [] in OrderedCollection>>collect:
OrderedCollection>>do:
OrderedCollection>>collect:
GlorpTutorialDescriptor(Glorp.DescriptorSystem)>>allDescriptors
GlorpTutorialDescriptor(Glorp.DescriptorSystem)>>validate
Glorp.GlorpSession>>system:
UndefinedObject>>unboundMethod
UndefinedObject(Object)>>performMethod:arguments:
UndefinedObject(Object)>>performMethod:
TextEditorController(ParagraphEditor)>>evaluateCompiled:
optimized [] in ParagraphEditor>>evaluateSelection
BlockClosure>>ensure:
Cursor>>showWhile:
TextEditorController(ParagraphEditor)>>evaluateSelection
optimized [] in ParagraphEditor>>doIt
BlockClosure>>on:do:
TextEditorController(ParagraphEditor)>>doIt
WorkspacePage>>doIt
Workbook(AbstractWorkspace)>>smalltalkDoIt
optimized [] in ApplicationModel>>actionFor:
optimized [] in ToolBar>>newButtonFor:
PluggableAdaptor>>setValue:
PluggableAdaptor(ValueModel)>>value:
TriggerButtonController>>pressAction
TriggerButtonTracker(BasicButtonTracker)>>finishSelectionFor:
TriggerButtonTracker>>finishSelectionFor:
TriggerButtonTracker(SelectionTracker)>>redButtonReleasedEvent:
RedButtonReleasedEvent>>dispatchTo:
TriggerButtonTracker(SelectionTracker)>>handleEvent:
EventDispatcher>>dispatch:to:
EventDispatcher>>dispatchEvent:
RedButtonReleasedEvent(Event)>>dispatch
RedButtonReleasedEvent(Event)>>dispatchForWindowManager:
optimized [] in WindowManager>>safelyDispatchForWindowManager:
BlockClosure>>on:do:
WindowManager>>safelyDispatchForWindowManager:
WindowManager>>processNextEvent
optimized [] in [] in WindowManager>>newProcess
BlockClosure>>on:do:
optimized [] in WindowManager>>newProcess
BlockClosure>>on:do:
optimized [] in Process class>>forBlock:priority:

----------------------------------------------------------------------
UndefinedObject(Object)>>doesNotUnderstand:
Receiver:
        an UndefinedObject
Arguments:
        aMessage = a Message with selector: #system and arguments: #()
Temporaries:
        excpt = a MessageNotUnderstood
        resumeValue = nil
Context PC = 25

----------------------------------------------------------------------
Glorp.DictionaryMapping(Glorp.Mapping)>>system
Receiver:
        a Glorp.DictionaryMapping
Instance Variables:
        descriptor = nil
        canRead = true
        canWrite = true
        attribute = ~~~~>>entries
        debugRead = false
        debugWrite = false
        query = nil
        join = nil
        usesLinkTable = true
        shouldProxy = true
        linkTableJoin = nil
        targetTableJoin = nil
        reverseJoin = nil
        shouldUseFilteredRead = false
        rowMapKeyConstructorBlock = nil
        controlsTables = true
        isExclusive = false
        linkFields = nil
        proxyAction = nil
        orderBy = nil
        shouldWriteTheOrderField = false
        keyMapping = nil
        valueMapping = nil
        associationDescriptor = a Glorp.Descriptor(a Glorp.Descriptor
Context PC = 5

----------------------------------------------------------------------
Glorp.DictionaryMapping>>associationDescriptor
Receiver:
        a Glorp.DictionaryMapping
Instance Variables:
        descriptor = nil
        canRead = true
        canWrite = true
        attribute = ~~~~>>entries
        debugRead = false
        debugWrite = false
        query = nil
        join = nil
        usesLinkTable = true
        shouldProxy = true
        linkTableJoin = nil
        targetTableJoin = nil
        reverseJoin = nil
        shouldUseFilteredRead = false
        rowMapKeyConstructorBlock = nil
        controlsTables = true
        isExclusive = false
        linkFields = nil
        proxyAction = nil
        orderBy = nil
        shouldWriteTheOrderField = false
        keyMapping = nil
        valueMapping = nil
        associationDescriptor = a Glorp.Descriptor(a Glorp.Descriptor
Context PC = 15

Johannes,

You will likely get a better response to your question on the Glorp
mailing list -- available from the Glorp web page (www.glorp.org),
although I beleive that Alan Knight also reads this list as well..

On Tue, July 3, 2007 11:38 am, Johannes Brauer wrote: