metadata.rb in imw-0.2.17

- old
+ new
@@ -2,64 +2,81 @@
 
   # A collection of classes for describing the metadata associated
   # with a dataset's fields.
   class Metadata < Hash
     
-    autoload :Field,       'imw/metadata/field'
-    autoload :Schema,      'imw/metadata/schema'
-    autoload :Schematized, 'imw/metadata/schematized'
-    autoload :DSL,         'imw/metadata/dsl'
+    autoload :Field,            'imw/metadata/field'
+    autoload :Schema,           'imw/metadata/schema'
     autoload :ContainsMetadata, 'imw/metadata/contains_metadata'
+    autoload :HasSummary,       'imw/metadata/has_summary'
+    autoload :HasMetadata,      'imw/metadata/has_metadata'
 
-    # The resource this Schema is anchored to.
+    # The resource this metadata is anchored to.
     #
     # This attribute is useful for letting relative paths in a
     # schema file refer to a common base URL.
     #
     # @return [IMW::Resource]
     attr_reader :base
     
-    # Set the resource this Schema is anchored to.
+    # Set the base resource this metdata is anchored to.
     #
     # @param [IMW::Resource, String, Addressable::URI] new_base
     def base= new_base
       base_resource = IMW.open(new_base)
-      base_resource.should_exist!("Metdata base directory must exist")
+      base_resource.should_exist!("Metadata base directory must exist")
       raise IMW::PathError.new("Metadata base must be a directory") unless base_resource.is_directory?
       @base = base_resource
     end
 
     def initialize obj=nil, options={}
       super()
       self.base = options[:base] if options[:base]
-      obj.each_pair { |resource, schema| self[resource] = Schema.new(schema) } if obj
+      if obj
+        obj.each_pair do |resource, metadata|
+          self[resource] = metadata
+        end
+      end
     end
 
-    def self.load metadata_resource, options
-      resource = IMW.open(metadata_resource)
+    def self.load obj, options={}
+      resource = IMW.open(obj)
       new(resource.load, {:base => resource.dirname}.merge(options))
     end
 
-    def []= resource_spec, schema_spec
-      schema = schema_spec.is_a?(Schema) ? schema_spec : Schema.new(schema_spec)
-      super(absolute_uri(resource_spec), schema_spec)
+    def []= resource, metadata
+      super(absolute_uri(resource), metadata)
     end
 
-    def [] resource_spec
-      super(absolute_uri(resource_spec))
+    def [] resource
+      super(absolute_uri(resource))
     end
 
-    def describe? resource_spec
-      has_key?(absolute_uri(resource_spec))
+    def describe? resource
+      self[(absolute_uri(resource))]
     end
+    alias_method :describes?, :describe?
 
+    def description_for resource
+      return unless describes?(resource)
+      self[resource]['description']
+    end
+
+    def fields_for resource
+      return unless describes?(resource)
+      (self[resource]['fields'] || []).map { |f| Metadata::Field.new(f) }
+    end
+
     protected
 
-    def absolute_uri resource_spec
-      if base && resource_spec.to_s !~ %r{(^/|://)} # relative path
-        base.join(resource_spec).to_s
+    def absolute_uri resource
+      obj = IMW.open(resource)
+      if base && obj.uri.to_s !~ %r{(^/|://)} # relative path
+        s = base.join(obj.uri.to_s).uri.to_s
+        s
       else
-        resource_spec.to_s
+        s = obj.uri.to_s
+        s
       end
     end
     
   end
 end