CrystalMind topic map engine

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Details...

CrystalMind is the name I gave to my topic map engine for no other reason than that the name stuck with me after reading the book The Last Legends of Earth and I thought it appropriate for a standard that's main objective is to achieve greater understanding.

See the JCrystalMind topic map project hosted at GitHub for an implementation of the CrystalMind topic map engine/store in Java.

The CrystalMind topic map engine has been successfully ported to Ruby, ActionScript 3 (Adobe AIR), Java (see link above, with branches for both MySQL and SQLite), PHP (for this site) and Android (Java). The original CrystalMind topic map engine was developed in Python.

Click here for a more detailed overview of topic maps.

A couple of notes with regards to the inheritance diagram above:

• the Node class is the super class of all other classes within the topic map engine. The Node class basically provides its sub-classes with both an identifier and an instance-of property (see source below). Specifically, the identifier field is important because it makes all objects 'addressable' within the topic map.
• the Association class inherits from the Topic class, meaning that associations themselves are topics! An example of when this could be of use will be provided below.

A detailed explanation of associations and how they have been implemented in the CrystalMind topic map engine. Pending...

node.py

import uuid
import unittest

from utils import Utils

#===============================================================================

class Node:

  def __init__(self, identifier=None, instance_of='node'):
    self.__identifier = (str(uuid.uuid1()) if identifier is None 
      else Utils.sanitize_id(str(identifier)))
    self.__instance_of = Utils.sanitize_id(instance_of)
    self.__meta_data = []

  @property
  def identifier(self):
    return self.__identifier

  @property
  def instance_of(self):
    return self.__instance_of

  @instance_of.setter
  def instance_of(self, value):
    self.__instance_of = Utils.sanitize_id(instance_of)

  @property
  def meta_data(self):
    return self.__meta_data

  def add_meta_datum(self, meta_datum):
    for meta_datum in meta_data:
      self.__meta_data.append(meta_datum)

  def add_meta_data(self, meta_data):
    for meta_datum in meta_data:
      self.__meta_data.append(meta_datum)

topic.py

import unittest

from node import Node
from occurrence import Occurrence

#===============================================================================

class Topic(Node):

  def __init__(self,
      identifier=None,
      instance_of='topic',
      base_name='undefined'):
    super().__init__(identifier, instance_of)

    self.__base_names = [base_name]
    self.__occurrences = []

  @property
  def base_names(self):
    return self.__base_names

  @property
  def first_name(self):
    return self.__base_names[0]

  @property
  def occurrences(self):
    return self.__occurrences

  def add_basename(self, base_name):
    self.__base_names.append(base_name)

  def remove_basename(self, base_name):
    self.__base_names = list(item for item in self.__base_names if item != base_name)

  def clear_basenames(self):
    self.__base_names[:] = []

  def create_occurrence(self,
      identifer=None,
      instance_of='occurrence',
      scope='*',
      resource_ref='',
      resource_data=None):
    occurrence = Occurrence(
      self.identifier,
      identifier,
      instance_of,
      scope,
      resource_ref,
      resource_data)
    self.__occurrences.append(occurrence)
    return occurrence

  def add_occurrence(self, occurrence):
    occurrence.topic_identifier = self.__identifier
    self.__occurrences.append(occurrence)

  def add_occurrences(self, occurrences):
    for occurrence in occurrences:
      self.__occurrences.append(occurrence)

occurrence.py

import unittest

from node import Node

from utils import Utils

#===============================================================================

class Occurrence(Node):

  def __init__(self,
      topic_identifier='',
      identifier=None,
      instance_of='occurrence',
      scope='*',
      resource_ref='',
      resource_data=None):

    super().__init__(identifier, instance_of)

    self.__scope = Utils.sanitize_id(scope)

    self.topic_identifier = Utils.sanitize_id(topic_identifier)
    self.resource_ref = resource_ref
    self.resource_data = resource_data

  @property
  def scope(self):
    return self.__scope

  @scope.setter
  def scope(self, value):
    self.__scope = Utils.sanitize_id(value)

member.py

import uuid
import unittest

from utils import Utils

#===============================================================================

class Member:

  def __init__(self, role_spec, topic_ref=None, identifier=None):
    self.__identifier = (str(uuid.uuid1()) if identifier is None 
      else Utils.sanitize_id(str(identifier)))
    self.role_spec = Utils.sanitize_id(role_spec)
    self.topic_refs = [] if topic_ref is None else [Utils.sanitize_id(topic_ref)]

  @property
  def identifier(self):
    return self.__identifier

  def add_topicref(self, topic_ref):
    self.topic_refs.append(Utils.sanitize_id(topic_ref))

  def remove_topicref(self, topic_ref):
    self.topic_refs.remove(topic_ref)

  def clear_topicrefs(self):
    self.topic_refs[:] = []

association.py

import unittest

from topic import Topic
from member import Member

from utils import Utils

#===============================================================================

class Association(Topic):

  def __init__(self,
      src_role_spec='',
      src_topic_ref='',
      dest_role_spec='',
      dest_topic_ref='',
      identifier=None,
      instance_of='association',
      scope='*',
      base_name='undefined'):

    super().__init__(identifier, instance_of, base_name)

    self.__members = []
    self.__scope = Utils.sanitize_id(scope)

    if (src_role_spec != '' and src_topic_ref != '' 
        and dest_role_spec != '' and dest_topic_ref != ''):
      src_member = Member(src_role_spec, src_topic_ref)
      dest_member = Member(dest_role_spec, dest_topic_ref)
      self.__members.append(src_member)
      self.__members.append(dest_member)

  @property
  def members(self):
    return self.__members

  @property
  def scope(self):
    return self.__scope

  @scope.setter
  def scope(self, value):
    self.__scope = Utils.sanitize_id(value)

  def create_member(self, role_spec, topic_ref):
    member = Member(role_spec, topic_ref)
    self.__members.append(member)

  def create_members(self, src_role_spec, src_topic_ref, dest_role_spec, dest_topic_ref):
    src_member = Member(src_role_spec, src_topic_ref)
    dest_member = Member(dest_role_spec, dest_topic_ref)
    self.__members.append(src_member)
    self.__members.append(dest_member)

  def add_member(self, member):
    self.__members.append(member)

  def get_member(self, identifier):
    pass

  def remove_member(self, identifier):
    self.__base_names = 
      list(item for item in self.__members if item.identifier != identifier)

  def clear_members(self):
    self.__members[:] = []