MQdb::DBObject(3) DESCRIPTION of Object

SYNOPSIS

Root class for all objects in MappedQuery toolkit

DESCRIPTION

Root object for toolkit and all derived subclasses. All objects in the MappedQuery structure are designed to be persisted in a database. Here database is a more broad term and can be considered any object persistance systems. Currently the toolkit works with SQL based systems but object databases or custom storage engines are possible. Provides base common methods used by all objects.

AUTHOR

Contact Jessica Severin: [email protected]

LICENSE

 * Software License Agreement (BSD License)
 * MappedQueryDB [MQdb] toolkit
 * copyright (c) 2006-2009 Jessica Severin
 * All rights reserved.
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Jessica Severin nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

APPENDIX

The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _

new

  Description: instance creation method
  Returntype : instance of this Class (subclass)
  Exceptions : none

init

  Description: initialization method which subclasses can extend
  Returntype : $self
  Exceptions : subclass dependent

copy

  Description: Shallow copy which copies all base attributes of object 
               to new instance of same class
  Returntype : same as calling instance
  Exceptions : subclass dependent

class

  Description: fixed string symbol for this class. Must be implemented 
               for each subclass and each subclass within toolkit 
               should return a unique name. used by global  methods.
  Returntype : string
  Exceptions : error if subclass does not redefine

database

  Description: the MQdb::Database where this object is permanently persisted to.
               Here database is any object persistance system.
  Returntype : MQdb::Database
  Exceptions : die if invalid setter value type is provided

primary_id

  Description: the unique identifier for this object within database.
  Returntype : scalar or UNDEF
  Exceptions : none

id

  Description: the unique identifier for this object within database.
               Returns empty string if not persisted.
  Returntype : scalar or ''
  Exceptions : none

db_id

  Description: the worldwide unique identifier for this object.
               A URL-like combination of database, class, and id
  Returntype : string or undef if database is not defined
  Exceptions : none

display_desc

  Description: general purpose debugging method that returns a nice
               human readable description of the object instance contents.
               Each subclass should implement and return a nice string.
  Returntype : string scalar 
  Exceptions : none

display_info

  Description: convenience method which prints the display_desc string
               with a carriage return to STDOUT. useful for debugging.
  Returntype : none
  Exceptions : none

xml

  Description: every object in system should be persistable in XML format.
               returns an XML description of the object and all child objects.
               Each subclass must implement and return a proper XML string.
               Best if one implements xml_start() and xml_end() and use here.
  Returntype : string scalar 
  Exceptions : none 
  Default    : default is a simple xml_start + xml_end

xml_start

  Description: every object in system should be persistable in XML format.
               returns an XML description of the object and all child objects.
               Each subclass should OVERRIDE this method and return a proper XML string.
               xml_start is the primary XML start tag
  Example    : return sprintf("<feature id='%d' name='%d' ..... >", $id, $name....);
  Returntype : string scalar 
  Exceptions : none

xml_end

  Description: every object in system should be persistable in XML format.
               returns an XML description of the object and all child objects.
               Each subclass should OVERRIDE this method and return a proper XML string.
               xml_end is the primary XML end tag 
  Example    : return "</feature>";
  Returntype : string scalar 
  Exceptions : none

simple_xml

  Description: short hand for xml_start() . xml_end()
               Can be used when only the primary XML start tag and attributes are needed
               No need to override if xml_start() and xml_end() are implemented
  Returntype : string scalar 
  Exceptions : none