root/Explorator/trunk/app/models/explorator_application.rb @ 128

#This class is a pool of sets. Each set should has a set of RDFS::Resources
#This class is a singleton pattern.
#Author: Samur Araujo
#Date: 25 jun 2008.
class EXPLORATOR::Application < RDFS::Resource
  self.class_uri = RDFS::Resource.new('http://www.tecweb.inf.puc-rio.br/ontologies/2008/explorator/01/core#Application')   
  def initialize(uri)
    super(uri)                                                   
  end
  def is_current?()
    if self.to_s == Application.instance.to_s         
      return true
    end
    false
  end                                 
end
class Application  
   attr_accessor :uri

  def initialize(id)   
    super()
    @uri = 'http://www.tecweb.inf.puc-rio.br/application/id/'+  id + '/'
  end
  def instance()    
    if @instance == nil     
      @cache = Hash.new
      @instance=EXPLORATOR::Application.new(@uri + 'default')
      @instance.explorator::uuid=@uri
      @instance.rdfs::label='Default'
      @instance.save
    end 
    @instance
  end
  #checks whether it is the current application
  
  #create a new entry in the pool
  def add(resourceset)    
    raise ExploratorError.new('Must be a ResourceSet instance') if !resourceset.instance_of? EXPLORATOR::Set
    puts '## Adding to cache ##'
    puts resourceset.uri
    @cache['<' + resourceset.uri + '>'] = resourceset
    
    if instance.explorator::set == nil
      instance.explorator::set = [resourceset]
    else
      instance.explorator::set = instance.all_explorator::set | [resourceset]
    end
  end    
  #get a resource set
  def get(uri)        
    #EXPLORATOR::Set.new(uri) 
    puts '## Retrieving from the cache ##'
    puts uri
    @cache[uri]
  end    
  ##verifies whether the set was added in the pool
  def is_set?(uri)    
    if instance.explorator::set == nil
      return false
    end           
    instance.all_explorator::set.collect {|x| x.to_s }.include?(uri)      
  end    
  #gets the list of all sets from the current application
  def sets 
    all = instance.all_explorator::set       
    if all == nil
      Array.new        
    end
    all
  end
  #save the environment as an application. This will creates an EXPLORATOR::Application instance and add all 
  #set to it.
  def create(name)      
    xapp = EXPLORATOR::Application.new(@uri + name)    
    xapp.save
    resources = instance.all_explorator::set
    xapp.explorator::set = resources
    xapp.rdfs::label=name 
    xapp.explorator::uuid=@uri
    # $instance = xapp     
    @instance=xapp
  end
  #remove all set from the pool
  def clear      
    #remove each set by itself
    s= instance.all_explorator::set
    if s != nil
      s.each do |resource|
        apps = Query.new.distinct(:s).where(:s,:p,resource).execute         
        if apps.size == 1 
          SemanticExpression.new.delete(resource,nil,nil)
        end
      end
    end
    @cache = Hash.new
    #remove the resources from the application
    instance.explorator::set = []
    instance.save      
  end     
  #load a saved application
  def load(uri)    
    puts "Loading ...  " + uri
    #$instance = EXPLORATOR::Application.new(uri)  
    @instance=EXPLORATOR::Application.new(uri)  
    #puts  instance.all_explorator::set.size
  end
  #deletes an application
  def delete(uri)    
    #can not delete the current application
    if uri == instance.to_s       
      return false
    end
    app = EXPLORATOR::Application.new(uri)     
    app.all_explorator::set.each do |resource|
      #delete the set only whether is only referenced by the current application
      apps = Query.new.distinct(:s).where(:s,:p,resource).execute        
      if apps.size == 1 
        SemanticExpression.new.delete(resource,nil,nil)
      end        
    end
    #remove the resources from the application
    SemanticExpression.new.delete(app,nil,nil)      
    true
  end    
  #remove a specific resource set from the pool
  def remove(uri)      
    @cache[uri]=nil
    resource = EXPLORATOR::Set.new(uri)     
    #before remove store the set expression.     
    exp = resource.explorator::expression
    #remove the set from the application
    instance.explorator::set = instance.all_explorator::set - [resource] 
    #replace the expresssion in all expressions that used the set as parameter.
    #this is necessary for avoid missing reference.
    instance.all_explorator::set.each do |expset| 
      expset.explorator::expression=expset.explorator::expression.gsub("'" + uri + "'",exp) 
    end
    #remove the set by itself
    apps = Query.new.distinct(:s).where(:s,:p,resource).execute        
    if apps.size == 1 
      SemanticExpression.new.delete(resource,nil,nil)
    end      
    instance.save
  end  
end