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Re: Issue with Spira has_many

From: Ben Lavender <blavender@gmail.com>
Date: Tue, 1 Feb 2011 21:03:31 +0100
Message-ID: <AANLkTin-qN9mzF6SL9N+BRdc=PfdH0tMFU06rABNOP9D@mail.gmail.com>
To: Daniel Gagne <danny@dannygagne.com>
Cc: Greg Lappen <greg@lapcominc.com>, public-rdf-ruby@w3.org
You infer correctly that it's a class loader issue; I haven't tested
Spira with rails. Danny is correct in that a more specific reference
to the class is probably required.

Ben

On Tue, Feb 1, 2011 at 8:55 PM, Daniel Gagne <danny@dannygagne.com> wrote:
> it looks like it can't find the symbol perhaps try
>
> type => :'OpenMedia::Schema::SKOS::Concept'
>
> or
>
> type => OpenMedia::Schema::SKOS::Concept
>
> danny
>
> On Tue, Feb 1, 2011 at 2:49 PM, Greg Lappen <greg@lapcominc.com> wrote:
>> Hello again everyone,
>> I am now attempting to do some integration of RDF with our Ruby on Rails
>> application, and found the Spira project which I have to say is just awesome
>> - it's a perfect fit for what we want to do.  I'm having a small problem
>> though with getting relationships between our Spira resources to work.  I
>> basically have one class, and it is going to "have many" of another class.
>>  The subject matter happens to be SKOS concept and concept schemes.  Here's
>> the basic code:
>> in app/models/open_media/schema/skos/concept.rb:
>> class OpenMedia::Schema::SKOS::Concept
>>   include Spira::Resource
>>
>>   default_source :types
>>   base_uri "http://data.openmedia.org/"
>>   type SKOS.Concept
>>   property :label, :predicate=>SKOS.label, :type=>XSD.string
>> end
>> in app/models/open_media/schema/skos/concept_scheme.rb:
>> class OpenMedia::Schema::SKOS::ConceptScheme
>>   include Spira::Resource
>>
>>   default_source :types
>>   base_uri "http://data.openmedia.org/"
>>   type SKOS.ConceptScheme
>>   property :label, :predicate=>SKOS.prefLabel, :type=>XSD.string
>>   has_many :top_concepts, :predicate=>SKOS.hasTopConcept, :type=>:Concept
>> end
>> So with the has_many type being the symbol :Concept, I get the following
>> error:
>> ArgumentError: OpenMedia::Schema::SKOS is not missing constant Concept!
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:479:in
>> `load_missing_constant'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:183:in
>> `const_missing'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:181:in
>> `each'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/activesupport-3.0.3/lib/active_support/dependencies.rb:181:in
>> `const_missing'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/dsl.rb:209:in
>> `const_get'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/dsl.rb:209:in
>> `qualified_const_get'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/rdf-0.3.1/lib/rdf/ntriples/reader.rb:184:in
>> `inject'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/dsl.rb:209:in
>> `each'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/dsl.rb:209:in
>> `inject'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/dsl.rb:209:in
>> `qualified_const_get'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/dsl.rb:178:in
>> `classize_resource'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/dsl.rb:142:in
>> `build_value'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/spira-0.0.11/lib/spira/resource/instance_methods.rb:91:in
>> `reload_attributes'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/rdf-0.3.1/lib/rdf/mixin/queryable.rb:70:in
>> `each'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/rdf-0.3.1/lib/rdf/mixin/queryable.rb:70:in
>> `grep'
>> from
>> /Users/greg/.rvm/gems/ree-1.8.7-2010.02@openmedia/gems/rdf-0.3.1/lib/rdf/mixin/queryable.rb:70:in
>> `each'
>> Without the relationship between them, both classes work great.  Am I right
>> in thinking it's a disagreement between Rails class loading mechanism and
>> how Spira is trying to load the has_many type?  I can reference
>> OpenMedia::Schema::SKOS::Concept fine in rails console, but as soon as I
>> save the concept scheme with a concept in the has_many, I get this error.
>>  Any ideas?  I was prepared to fix this and submit a patch, but an hour
>> later, no such luch.  Thanks!
>> Greg
>
>
Received on Tuesday, 1 February 2011 20:04:27 GMT

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