Class: Pho::Update::Changeset

Inherits:
Object
  • Object
show all
Defined in:
lib/pho/changeset.rb

Overview

Models a Changeset: a delta to an RDF graph

The RDF Schema for Changesets can be found at:

http://vocab.org/changeset/schema

Further reading:

http://n2.talis.com/wiki/Changesets

The Platform Changeset protocol is described at:

http://n2.talis.com/wiki/Changeset_Protocol

Processing of batch changesets is described at:

http://n2.talis.com/wiki/Metabox

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(subject_of_change, creator_name = nil, change_reason = nil) {|_self| ... } ⇒ Changeset

Constructor. Parameter should be the URI of the subject of change

subject_of_change

the URI of the resource being changed

creator_name

the name of the creator of this change (optional)

change_reason

the reason for the change (optional)

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/pho/changeset.rb', line 222

def initialize(subject_of_change, creator_name=nil, change_reason=nil)
  u = URI.parse(subject_of_change)
  #this should catch literals
  if u.scheme() == nil
    raise URI::InvalidURIError.new("Invalid URI")
  end
  @subject_of_change = subject_of_change
  @creator_name = creator_name
  @change_reason = change_reason
  @additions = Array.new
  @removals = Array.new
  yield self if block_given?
end

Instance Attribute Details

#change_reason ⇒ Object

Reason for the change being made



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# File 'lib/pho/changeset.rb', line 215

def change_reason
  @change_reason
end

#creator_name ⇒ Object

Creator name



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# File 'lib/pho/changeset.rb', line 213

def creator_name
  @creator_name
end

#subject_of_change ⇒ Object (readonly)

URI of the subject of change for this changeset



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# File 'lib/pho/changeset.rb', line 211

def subject_of_change
  @subject_of_change
end

Instance Method Details

#add_addition(statement) ⇒ Object

Include a Statement in the Changeset as an addition



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# File 'lib/pho/changeset.rb', line 281

def add_addition(statement)
  if statement.subject != @subject_of_change
    raise "Subject of statement must match subject of change of changeset"
  end
  @additions << statement
end

#add_additions(statements) ⇒ Object

Add an array of statements as additions



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# File 'lib/pho/changeset.rb', line 289

def add_additions(statements)
  statements.each do |statement|
    add_addition(statement)
  end
end

#add_removal(statement) ⇒ Object

Include a Statement in the Changeset as a removal



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# File 'lib/pho/changeset.rb', line 301

def add_removal(statement)
  if statement.subject != @subject_of_change
    raise "Subject of statement must match subject of change of changeset"
  end
  @removals << statement
end

#add_removals(statements) ⇒ Object

Add an array of statements as removals



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# File 'lib/pho/changeset.rb', line 309

def add_removals(statements)
  statements.each do |statement|
    add_removal(statement)
  end
end

#additions ⇒ Object

Return the Statement describing the addition in this Changeset



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# File 'lib/pho/changeset.rb', line 276

def additions()
  return @additions
end

#removals ⇒ Object

Return the list of Statements describing the removals in this Changeset



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# File 'lib/pho/changeset.rb', line 296

def removals()
  return @removals
end

#submit(store, versioned = false) ⇒ Object

Submit this changeset to the specified store

store

the store to which the changeset should be applied



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# File 'lib/pho/changeset.rb', line 318

def submit(store, versioned=false)
  return store.submit_changeset(self.to_rdf, versioned)
end

#to_rdf(include_root = true) ⇒ Object

Serialize this changeset as RDF/XML suitable for submitting to the Platform.



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# File 'lib/pho/changeset.rb', line 241

def to_rdf(include_root=true)
  rdf = ""
  if include_root
    rdf << "<rdf:RDF xmlns:cs=\"http://purl.org/vocab/changeset/schema#\" xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">"  
  end
  
  rdf << " <cs:ChangeSet>"
  rdf << "  <cs:subjectOfChange rdf:resource=\"#{@subject_of_change}\"/>"
  if @creator_name
    rdf << "  <cs:creatorName>#{@creator_name}</cs:creatorName>"
  end
  if @change_reason
    rdf << "  <cs:changeReason>#{@change_reason}</cs:changeReason>"
  end
  @additions.each do |add|
      rdf << "  <cs:addition>"
      rdf << add.to_rdf
      rdf << "  </cs:addition>"                                
  end
  @removals.each do |remove|
    rdf << "  <cs:removal>"
    rdf << remove.to_rdf
    rdf << "  </cs:removal>"                                
  end
  
  rdf << " </cs:ChangeSet>"
  
  if include_root
    rdf << "</rdf:RDF>"  
  end
  
  return rdf        
end

#to_s ⇒ Object 



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# File 'lib/pho/changeset.rb', line 236

def to_s
  return to_rdf
end