Method for providing stand-in objects

• US 7,523,458 B2
• Filed: 09/23/2005
• Issued: 04/21/2009
• Est. Priority Date: 12/07/1994
• Status: Expired due to Fees

• Current Assignee: Next Software Incorporated (Apple Inc.)
• Original Assignee: Next Software Incorporated (Apple Inc.)
• Inventors: Williamson, Richard, Upson, Linus, Greenfield, Jack, Willhite, Daniel
• Primary Examiner(s): An; Meng-Ai
• Assistant Examiner(s): PRICE, NATHAN E
• Application Number:
  US11/233,802
• Publication Number:
  US 20060026562A1
• Time in Patent Office: 1,306 Days
• Field of Search: 719/313, 719/331, 719/332, 719/316
• US Class Current: 719/313
• CPC Class Codes: G06F 8/24 Object-oriented
• CPC Class Codes: G06F 9/4488 Object-oriented
• CPC Class Codes: G06F 9/449 Object-oriented method invocation or resolution
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

A method for providing stand-in objects, where relationships among objects are automatically resolved in an object oriented relational database model without the necessity of retrieving data from the database until it is needed. A “fault” class is defined, as well as fault objects whose data haven'"'"'t yet been fetched from the database. An object that'"'"'s created for the destination of a relationship whenever an object that includes the relationship is fetched from the database. When an object is fetched that has relationships, fault objects are created to “stand-in” for the destination objects of those relationships. Fault objects transform themselves into the actual enterprise objects—and fetch their data—the first time they'"'"'re accessed. Subsequently, messages sent to the target objects are responded to by the objects themselves.

Claims

1. A method for deferring instantiation of an object in an object-oriented programming environment, comprising:

instantiating a first object having a relationship with a second object; and

instantiating a fault object as a placeholder for the second object;

wherein instantiation of the second object is deferred until a message for the second object can not be responded to by the fault object; and

wherein the fault object is configured to respond, on behalf of and in the same manner as the second object, to a subset including at least one message but not all messages comprising a set of messages to which the second object is configured to respond.

2. A method as recited in claim 1, wherein the fault object includes a pointer to data to be used to initialize the second object.

3. A method as recited in claim 2, wherein the pointer is stored in an instance variable of the fault object.

4. A method as recited in claim 1, further comprising receiving a message for the second object and responding to the message by the fault object when the fault object is able to respond to the message.

5. A method as recited in claim 1, further comprising receiving a message for the second object and instantiating the second object in place of the fault object when the fault object is not able to respond to the message.

6. A method as recited in claim 1, further comprising defining a fault class from which the fault object is instantiated.

7. A method as recited in claim 6, wherein the fault class defines single-fault objects which resolve to-one relationships.

8. A method as recited in claim 6, wherein the fault class defines array fault objects which resolve to-many relationships.

9. A method as recited in claim 6, wherein the fault class includes one or more of class, retain, and release methods.

10. A method as recited in claim 1, wherein at least one of the objects comprises an enterprise object.

11. A method as recited in claim 1, wherein at least one of the objects includes at least one property that maps to data stored in a data storage device.

12. A method as recited in claim 1, wherein the second object comprises a record in a database.

13. A method as recited in claim 1, further comprising instantiating additional fault objects as placeholders for other objects that have relationships with the first object.

14. A method as recited in claim 1, further comprising instantiating the second object by transforming the fault object into the second object using a class definition of the second object.

15. A system for deferring instantiation of an object in an object-oriented programming environment, comprising:

a processor configured to;

instantiate a first object having a relationship with a second object; and

instantiate a fault object as a placeholder for the second object; and

a memory coupled to the processor and configured to provide the processor with instructions;

wherein instantiation of the second object is deferred until a message for the second object can not be responded to by the fault object; and

wherein the fault object is configured to respond, on behalf of and in the same manner as the second object, to a subset including at least one message but not all messages comprising a set of messages to which the second object is configured to respond.

16. A system as recited in claim 15, wherein the fault object includes a pointer to data to be used to initialize the second object.

17. A system as recited in claim 15, wherein the processor is further configured to receive a message for the second object and the fault object is configured to respond to the message when the fault object is able to respond to the message.

18. A system as recited in claim 15, wherein the processor is further configured to receive a message for the second object and instantiate the second object in place of the fault object when the fault object is not able to respond to the message.

19. A system as recited in claim 15, wherein the processor is further configured to instantiate the second object by transforming the fault object into the second object using a class definition of the second object.