Class: TaliaCore::Source

Inherits:
ActiveSource show all
Defined in:
lib/talia_core/source.rb

Overview

Base class for most sources in the Talia system. The Source class has some additional features over the basic ActiveSource class.

Most importantly, it contains the “smart” accessor in the same style as ActiveRDF:

source.rdf::something
=> SemanticCollection Wrapper

# is the same as:
source[N::RDF.something]

There are also

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from ActiveSource

#[], #[]=, #add_additional_rdf_types, #add_semantic_attributes, #attach_files, #data, #db_attr?, #defined_property?, #direct_predicates, #inverse, #inverse_predicates, #predicate, #predicate_replace, #predicate_set, #predicate_set_uniq, #property_options_for, #rdf_selftype, #reload, #rewrite_attributes, #rewrite_attributes!, #short_uri, #to_rdf, #to_s, #to_uri, #to_xml, #update_attributes, #update_attributes!, #update_attributes_orig, #update_attributes_orig!, #update_source, #value_for, #write_predicate_direct

Methods included from ActiveSourceParts::ClassMethods

#additional_rdf_types, #create_from_xml, #create_multi_from, #create_source, #db_attr?, #defined_property?, #exists?, #expand_uri, #new, #paginate, #property_options_for, #props_to_destroy, #rewrite, #split_attribute_hash, #update, #value_for

Methods included from ActiveSourceParts::Finders

#count, #find, #find_by_partial_local, #find_by_partial_uri, #find_by_uri_token

Methods included from ActiveSourceParts::SqlHelper

#default_inv_joins, #default_joins, #props_join, #sources_join

Methods included from ActiveSourceParts::PredicateHandler::ClassMethods

#prefetch_relations_for

Methods included from TaliaUtil::Progressable

#progressor, #progressor=, #run_with_progress

Methods included from ActiveSourceParts::RdfHandler

#autosave_rdf=, #autosave_rdf?, #create_rdf, #my_rdf, #to_rdf

Methods included from ActiveSourceParts::PredicateHandler

#each_cached_wrapper, #get_objects_on, #get_wrapper_on, #has_type?, #inject_predicate, #reset!, #save_wrappers, #types

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args) ⇒ Object (protected)

Missing methods: This just check if the given method corresponds to a registered namespace. If yes, this will return a DummyHandler that allows access to properties.

This will allow invocations such as namespace::name

Raises:

  • (ArgumentError) 


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# File 'lib/talia_core/source.rb', line 273

def method_missing(method_name, *args)
  # TODO: Add permission checking for all updates to the model
  # TODO: Add permission checking for read access?

  update = method_name.to_s[-1..-1] == '='

  shortcut = if update 
    method_name.to_s[0..-2]
  else
    method_name.to_s
  end

  # Otherwise, check for the RDF predicate
  registered = N::URI[shortcut.to_s]

  return super(method_name, *args) unless(registered) # normal handler if not a registered uri
  raise(ArgumentError, "Must give a namspace as argument") unless(registered.is_a?(N::Namespace))

  DummyHandler.new(registered, self)
end

Instance Attribute Details

#predicates_attributes ⇒ Object

TODO: Delete this/old backend method?



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# File 'lib/talia_core/source.rb', line 132

def predicates_attributes
  @predicates_attributes
end

Class Method Details

.find_or_instantiate_by_uri(uri, local_name) ⇒ Object

Try to find a source for the given uri, if not exists it instantiate a new one, combining the N::LOCAL namespace and the given local name

Example:

ActiveSource.find_or_instantiate_by_uri('http://talia.org/existent')
  # => #<TaliaCore::ActiveSource id: 1, uri: "http://talia.org/existent">

ActiveSource.find_or_instantiate_by_uri('http://talia.org/unexistent', 'Foo Bar')
  # => #<TaliaCore::ActiveSource id: nil, uri: "http://talia.org/Foo_Bar">

TODO: Delete this/old backend method?



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# File 'lib/talia_core/source.rb', line 96

def self.find_or_instantiate_by_uri(uri, local_name) # :nodoc: 
  result = find_by_uri(uri)
  result ||= self.new(N::LOCAL.to_s + local_name.to_permalink)
end

.groups_by_property(property, values, params = {}) ⇒ Object

Searches for sources where property has one of the values given to this method. The result is a hash that contains one result list for each of the values, with the value as a key.

This performs a find operation for each value, and the params passed to this method are added to the find parameters for each of those finds.

Example

# Returns all Sources that are of the RDFS type Class or Property. This
# will return a hash with 2 lists (one for the Classes, and one for the
# properties, and each list will be limited to 5 elements.
Source.groups_by_property(N::RDF::type, [N::RDFS.Class, N::RDFS.Property], :limit => 5)



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# File 'lib/talia_core/source.rb', line 64

def self.groups_by_property(property, values, params = {})
  # First create the joins
  joins = 'LEFT JOIN semantic_relations ON semantic_relations.subject_id = active_sources.id '
  joins << "LEFT JOIN active_sources AS t_sources ON semantic_relations.object_id = t_sources.id AND semantic_relations.object_type = 'TaliaCore::ActiveSource' "
  joins << "LEFT JOIN semantic_properties ON semantic_relations.object_id = semantic_properties.id AND semantic_relations.object_type = 'TaliaCore::SemanticProperty' "

  property = uri_string_for(property, false)
  results = {}
  for val in values
    find(:all )
    val_str = uri_string_for(val, false)
    find_parms = params.merge(
    :conditions => ['semantic_properties.value = ? OR t_sources.uri = ?', val_str, val_str],
    :joins => joins
    )
    results[val] = find(:all, find_parms)
  end

  results
end

.normalize_uri(uri, label = '') ⇒ Object

Normalize the given uri.

Example:

normalize_uri('Lucca') # => http://www.talia.discovery-project.org/sources/Lucca
normalize_uri('http://xmlns.com/foaf/0.1/Group') # => http://xmlns.com/foaf/0.1/Group
normalize_uri('http://www.talia.discovery-project.org/sources/Lucca')
  # => http://www.talia.discovery-project.org/sources/Lucca



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# File 'lib/talia_core/source.rb', line 257

def normalize_uri(uri, label = '')
  uri = N::LOCAL if uri.blank?
  uri = N::LOCAL+label.gsub(' ', '_') if uri == N::LOCAL.to_s
  uri.to_s
end

Instance Method Details

#==(value) ⇒ Object

Equality test. Two sources are equal if they have the same URI



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# File 'lib/talia_core/source.rb', line 192

def ==(value)
  value.is_a?(Source) && (value.uri == uri)
end

#associated?(namespace, name, stringified_predicate) ⇒ Boolean

Check if the current source is related with the given rdf object (triple endpoint). TODO: Delete this/old backend method?

Returns:

  • (Boolean) 


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# File 'lib/talia_core/source.rb', line 122

def associated?(namespace, name, stringified_predicate) # :nodoc:
  predicate_objects(namespace, name).include?(stringified_predicate)
end

#collections ⇒ Object

Returns the Collection (or collections) this source is in.



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# File 'lib/talia_core/source.rb', line 202

def collections
  Collection.find(:all, :find_through => [N::DCT.hasPart, self])
end

#grouped_direct_predicates ⇒ Object

Return an hash of direct predicates, grouped by namespace. TODO: Delete this/old backend method?



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# File 'lib/talia_core/source.rb', line 103

def grouped_direct_predicates # :nodoc:
  #TODO should it be memoized?
  direct_predicates.inject({}) do |result, predicate|
    predicates = self[predicate].collect { |p| SourceTransferObject.new(p.to_s) }
    namespace = predicate.namespace.to_s
    result[namespace] ||= {}
    result[namespace][predicate.local_name] ||= []
    result[namespace][predicate.local_name] << predicates
    result
  end
end

#grouped_predicates_attributes ⇒ Object

Return an hash of new predicated attributes, grouped by namespace. TODO: Delete this/old backend method?



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# File 'lib/talia_core/source.rb', line 142

def grouped_predicates_attributes # :nodoc:
  @grouped_predicates_attributes ||= predicates_attributes.inject({}) do |result, predicate|
    namespace, name = predicate['namespace'], predicate['name']
    predicate = SourceTransferObject.new(predicate['titleized'])
    result[namespace] ||= {}
    result[namespace][name] ||= []
    result[namespace][name] << predicate
    result
  end
end

#label(type = N::RDFS::label) ⇒ Object

This returns a single label of the given type. (If multiple labels exist in the RDF, just the first is returned.)



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# File 'lib/talia_core/source.rb', line 180

def label(type = N::RDFS::label)
  labels(type)[0]
end

#labels(type = N::RDFS::label) ⇒ Object

Returns an array of labels for this source. You may give the name of the property that is used as a label, by default it uses rdf:label(s). If the given property is not set, it will return the local part of this Source’s URI.

In any case, the result will always be an Array with at least one elment.



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# File 'lib/talia_core/source.rb', line 169

def labels(type = N::RDFS::label)
  labels = get_attribute(type)
  unless(labels && labels.size > 0)
    labels = [uri.local_name]
  end

  labels
end

#local ⇒ Object

Indicates if this source belongs to the local store



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# File 'lib/talia_core/source.rb', line 35

def local
  uri.local?
end

#normalize_uri(uri, label = '') ⇒ Object

See Source.normalize_uri



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# File 'lib/talia_core/source.rb', line 197

def normalize_uri(uri, label = '')
  self.class.normalize_uri(uri, label)
end

#predicate_changed?(namespace, name, objects) ⇒ Boolean

Check if a predicate is changed. TODO: Delete this/old backend method?

Returns:

  • (Boolean) 


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# File 'lib/talia_core/source.rb', line 127

def predicate_changed?(namespace, name, objects) # :nodoc:
  not predicate_objects(namespace, name).eql?(objects.map(&:to_s))
end

#predicate_objects(namespace, name) ⇒ Object

TODO: Delete this/old backend method?



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# File 'lib/talia_core/source.rb', line 116

def predicate_objects(namespace, name) #:nodoc:
  predicate(namespace, name).values.flatten.map(&:to_s)
end

#primary_source ⇒ Object

Indicates if the current source is considered “primary” in the local library



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# File 'lib/talia_core/source.rb', line 47

def primary_source
  predicate(:talia, :primary_source) == true
end

#primary_source=(value) ⇒ Object

Shortcut for assigning the primary_source status



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# File 'lib/talia_core/source.rb', line 40

def primary_source=(value)
  value = value ? 'true' : 'false'
  predicate_set(:talia, :primary_source, value)
end

#save_predicates_attributes ⇒ Object

Save, associate/disassociate given predicates attributes. TODO: Delete this/ old backend method?



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# File 'lib/talia_core/source.rb', line 155

def save_predicates_attributes # :nodoc:
  each_predicate do |namespace, name, objects|
    objects.each { |object| object.save if object.is_a?(Source) && object.new_record? }
    self.predicate_replace(namespace, name, objects.to_s) if predicate_changed?(namespace, name, objects)
  end
end

#titleized ⇒ Object

Return the titleized uri local name.

http://localnode.org/source # => Source



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# File 'lib/talia_core/source.rb', line 187

def titleized
  self.uri.local_name.titleize
end

#uri ⇒ Object

The uri will be wrapped into an object



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# File 'lib/talia_core/source.rb', line 30

def uri
  N::URI.new(self[:uri])
end