Method for providing stand-in objects

• US 7,539,997 B2
• Filed: 07/31/2006
• Issued: 05/26/2009
• 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:
  US11/497,556
• Publication Number:
  US 20070039008A1
• Time in Patent Office: 1,030 Days
• Field of Search: 719/313, 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 managing object relationships comprising:

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

creating a fault object to stand in place of said second object with respect to said relationship;

wherein the fault object is configured (1) to appear to the first object in at least one respect to be the same as the second object and (2) to not retrieve at instantiation of the fault object, from a data source, a data that the second object would have retrieved from the data source at instantiation of the second object;

wherein the fault object is further configured to transform itself into or replace itself with the second object in the event an indication is received that a method associated with the data has been invoked.

2. A method as recited in claim 1, further comprising associating said first object with said fault object.

3. A method as recited in claim 1, wherein the fault object is further configured to transform itself into or replace itself with the second object in the event an indication is received that the data is required.

4. A method as recited in claim 1, wherein the indication comprises a message.

5. A method as recited in claim 1, wherein the indication comprises receiving a message to which the fault object is not configured to provide a valid response.

6. A method as recited in claim 1, wherein the fault object is configured to appear to the first object in at least one respect to be the same as the second object at least in part by being configured to respond to a message received from the first object in a same manner in which the second object would respond to the message.

7. A method as recited in claim 6, wherein the message to which the fault object is configured to respond as if the fault object were the same as the second object comprises one or more of the following:

autorelease;

class;

conformsToProtocol;

description;

isKindOfClass;

isMemberOfClass;

isProxy;

printForDebugger;

release;

respondsToSelector;

retain;

retainCount; and

zone.

8. A method as recited in claim 1, wherein the fault object is further configured to:

receive a message;

determine based at least in part on the message that the second object is needed; and

transform itself into the second object, in response to the determination that the second object is needed.

9. A method as recited in claim 8, wherein the fault object is configured to transform itself into the second object at least in part by retrieving the data from the data source.

10. A method as recited in claim 8, wherein the fault object is configured to transform itself into the second object at least in part by rewriting an attribute of the fault object to a value associated with the second object.

11. A method as recited in claim 10, wherein the value comprises a pointer or other identifier associated with a class description.

12. A method as recited in claim 1, wherein an actual class of which the second object is an instance is stored as an instance variable of the fault object.

13. A method as recited in claim 1, wherein the data source compnses one or more of the following:

a database;

an object-oriented database;

a user interface; and

a file system.

14. A computer program product for managing object relationships, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

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

creating a fault object to stand in place of said second object with respect to said relationship;

wherein the fault object is configured (1) to appear to the first object in at least one respect to be the same as the second object and (2) to not retrieve at instantiation of the fault object, from a data source, a data that the second object would have retrieved from the data source at instantiation of the second object;

wherein the fault object is further configured to transform itself into or replace itself with the second object in the event an indication is received that a method associated with the data has been invoked.

15. A computer program product as recited in claim 14, wherein the fault object is further configured to transform itself into or replace itself with the second object in the event an indication is received that the data is required.

16. A computer program product as recited in claim 14, wherein the fault object is configured to appear to the first object in at least one respect to be the same as the second object at least in part by being configured to respond to a message received from the first object in a same manner in which the second object would respond to the message.

17. A computer program product as recited in claim 14, wherein an actual class of which the second object is an instance is stored as an instance variable of the fault object.

18. A computer system, comprising:

a memory; and

a processor coupled to the memory and configured to;

create in said memory a first object having a relationship with a second object; and

create a fault object to stand in place of said second object with respect to said relationship;

wherein the fault object is configured (1) to appear to the first object in at least one respect to be the same as the second object and (2) to not retrieve at instantiation of the fault object, from a data source, a data that the second object would have retrieved from the data source at instantiation of the second object;

wherein the fault object is further configured to transform itself into or replace itself with the second object in the event an indication is received that a method associated with the data has been invoked.