Class: DataMapper::Session

Inherits:
Object
  • Object
show all
Defined in:
lib/data_mapper/session.rb

Defined Under Namespace

Classes: MaterializationError

Constant Summary collapse

FIND_OPTIONS = 
[
  :select, :limit, :class, :include, :reload, :conditions, :order
]

Instance Method Summary collapse

Constructor Details

#initialize(database) ⇒ Session

Returns a new instance of Session.



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# File 'lib/data_mapper/session.rb', line 15

def initialize(database)
  @database = database
end

Instance Method Details

#all(options) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 57

def all(options)
  set = LoadedSet.new(@database)
  reader = @database.query(options)
  instances = reader.map do |hash|
    load(options, hash, set)
  end
  reader.close
  return instances
rescue => error
  @database.log.error(error)
  raise error
end

#create_table(klass) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 171

def create_table(klass)
  @database.connection do |db|
    db.execute(@database.create_table_statement(klass))
  end unless table_exists?(klass)
end

#delete_all(klass) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 161

def delete_all(klass)
  @database.execute(@database.delete_statement(klass))
end

#destroy(instance) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 147

def destroy(instance)
  instance.class.callbacks.execute(:before_destroy, instance)
  result = @database.execute(@database.delete_statement(instance))
  if result.success?
    instance.instance_variable_set(:@new_record, true)
    instance.original_hashes.clear
    instance.class.callbacks.execute(:after_destroy, instance)
  end
  return result.success?
rescue => error
  @database.log.error(error)
  raise error
end

#drop_table(klass) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 177

def drop_table(klass)
  @database.connection do |db|
    db.execute(@database.drop_table_statement(klass))
  end if table_exists?(klass)
end

#find(klass, type_or_id, options = {}, &b) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 23

def find(klass, type_or_id, options = {}, &b)
  options.merge! b.to_hash if block_given?
  
  results = case type_or_id
    when :first then
      first(@database.select_statement(options.merge(:class => klass, :limit => 1)))
    when :all then
      all(@database.select_statement(options.merge(:class => klass)))
    else
      first(@database.select_statement(options.merge(:class => klass, :id => type_or_id)))
  end
  
  case results
    when Array then results.each { |instance| instance.session = self }
    when Base then results.session = self
  end
  return results
end

#first(options) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 42

def first(options)
  if options.has_id? && !options.reload?
    instance = identity_map.get(options.klass, options.instance_id)
    return instance unless instance.nil?
  end
  
  reader = @database.query(options)
  instance = reader.eof? ? nil : load(options, reader.next)
  reader.close
  return instance
rescue DatabaseError => de
  de.options = options
  raise de
end

#identity_map ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 19

def identity_map
  @identity_map || ( @identity_map = IdentityMap.new )
end

#insert(instance, inserted_id = nil) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 118

def insert(instance, inserted_id = nil)
  instance.class.callbacks.execute(:before_create, instance)
  result = @database.execute(@database.insert_statement(instance))
  
  if result.success?
    instance.instance_variable_set(:@new_record, false)
    instance.instance_variable_set(:@id, inserted_id || result.last_inserted_id)
    calculate_original_hashes(instance)
    identity_map.set(instance)
    instance.class.callbacks.execute(:after_create, instance)
  end
  
  return result
rescue => error
  @database.log.error(error)
  raise error
end

#load(options, hash, set = LoadedSet.new(@database)) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 70

def load(options, hash, set = LoadedSet.new(@database))
        
  instance_class = unless hash['type'].nil?
    Kernel::const_get(hash['type'])
  else
    options.klass
  end
  
  mapping = @database[instance_class]
  
  instance_id = mapping.key.type_cast_value(hash['id'])      
  instance = identity_map.get(instance_class, instance_id)
  
  if instance.nil? || options.reload?
    instance ||= instance_class.new        
    instance.class.callbacks.execute(:before_materialize, instance)
    
    instance.instance_variable_set(:@new_record, false)
    hash.each_pair do |name_as_string,raw_value|
      name = name_as_string.to_sym
      if column = mapping.find_by_column_name(name)
        value = column.type_cast_value(raw_value)
        instance.instance_variable_set(column.instance_variable_name, value)
      else
        instance.instance_variable_set("@#{name}", value)
      end
      instance.original_hashes[name] = value.hash
    end

    instance.class.callbacks.execute(:after_materialize, instance)
    
    identity_map.set(instance)
  end
  
  instance.instance_variable_set(:@loaded_set, set)
  set.instances << instance
  return instance
end

#log ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 220

def log
  @database.log
end

#query(*args) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 192

def query(*args)
  sql = args.shift
  
  unless args.empty?
    sql.gsub!(/\?/) do |x|
      @database.quote_value(args.shift)
    end
  end

  reader = @database.connection do |db|
    db.query(sql)
  end
  
  columns = reader.columns.keys
  klass = Struct.new(*columns.map { |c| c.to_sym })
  
  rows = reader.map do |row|
    klass.new(*columns.map { |c| row[c] })
  end
  
  reader.close
  return rows
end

#save(instance) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 109

def save(instance)
  return false unless instance.dirty?
  instance.class.callbacks.execute(:before_save, instance)
  result = instance.new_record? ? insert(instance) : update(instance)
  instance.session = self
  instance.class.callbacks.execute(:after_save, instance)
  result.success?
end

#schema ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 216

def schema
  @database.schema
end

#table_exists?(klass) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_mapper/session.rb', line 183

def table_exists?(klass)
  reader = @database.connection do |db|
    db.query(@database.table_exists_statement(klass))
  end
  result = !reader.eof?
  reader.close
  result
end

#truncate(klass) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 165

def truncate(klass)
  @database.connection do |db|
    db.execute(@database.truncate_table_statement(klass))
  end
end

#update(instance) ⇒ Object 



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# File 'lib/data_mapper/session.rb', line 136

def update(instance)
  instance.class.callbacks.execute(:before_update, instance)
  result = @database.execute(@database.update_statement(instance))
  calculate_original_hashes(instance)
  instance.class.callbacks.execute(:after_update, instance)
  return result
rescue => error
  @database.log.error(error)
  raise error
end