Robust modification of persistent objects while preserving formatting and other attributes

• US 6,347,323 B1
• Filed: 03/26/1999
• Issued: 02/12/2002
• Est. Priority Date: 03/26/1999
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Crowley, Terrence R., Stefanik, Theodore J., Angiulo, Michael A., Garber, David G.
• Primary Examiner(s): Coby, Frantz
• Application Number:
  US09/282,027
• Time in Patent Office: 1,054 Days
• Field of Search: 707/203, 707/8, 707/100, 707/101, 707/102
• US Class Current: 1/1
• CPC Class Codes: G06F 16/986 Document structures and storage, e.g. HTML extensions
• CPC Class Codes: G06F 40/103 Formatting, i.e. changing of presentation of documents automatic justification G06F40/189; automatic line break hyphenation G06F40/191
• CPC Class Codes: G06F 40/166 Editing, e.g. inserting or deleting
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

A method and system for preserving attributes of objects within a file that was created in a different environment from that in which the file is opened, enabling the attributes to be maintained after the file is saved. For example, an HTML document created with a text editor includes elements such as plain text and HTML tags, with which attributes such as whitespace, line breaks, and indent level are associated. When such a document is opened in an HTML editor implementing the present invention, the attributes of these elements are preserved. Even when changes to these elements occur, to the extent possible, the method provides for determining attributes of related elements that were in the document as originally opened in the HTML editor, so that these attributes can be applied to corresponding objects that are added to the document or in regard to changes that are made by the user. The preservation of persistent object attributes is also applicable to other types of software applications such as language development systems and word processing programs. This invention thus insures, for example, that functions developed in newer versions of a program, although not recognized in an earlier version, persist when a file is opened in the earlier version and then saved.

Claims

1. A method for preserving attributes of a persistent object stream in a file that includes at least one object when the file is opened in a different environment than that in which the file was originally created, comprising the steps of:

(a) creating a copy of attributes associated with each object when opening the file in the different environment, said copy including attributes that are unknown to said different environment;

(b) ignoring any of said attributes associated with each object that are unknown to the different environment; and

(c) when writing the file, merging known attributes associated with each object that are changed in the different environment, with the copy of the attributes associated with the object, including any attributes that are unknown.

2. The method of claim 1, wherein objects in the file include text entries having whitespace attributes, and wherein a whitespace attribute that is associated with a text entry is preserved in the copy unless changed while the file is open in said different environment.

3. The method of claim 1, wherein objects in the file include tag entries having whitespace attributes, and wherein a whitespace attribute associated with a tag entry is preserved in the copy unless changed while the file is open in said different environment.

4. The method of claim 1, wherein objects in any class that is unknown in the different environment are preserved in the copy and are ignored in the different environment, but are merged with known objects when the file is written.

5. The method of claim 1, wherein the attributes for an object that is unknown to the different environment reference a function associated with the object that is not recognized in the different environment, but is recognized in the environment in which the object was first added to the file.

6. The method of claim 1, further comprising the steps of parsing the file to identify the persistent object stream, and creating a different internal representation of the attributes associated with objects in the file for use in the copy that is created.

7. The method of claim 1, further comprising the steps of determining attributes of the persistent object stream determined when the file was opened and applying said attributes to any related new objects that are added to the file while the file is open, so that attributes of the new objects are consistent with the persistent object stream.

8. The method of claim 1, wherein changes to the file are minimized to insure that the attributes of objects in the file are retained.

9. A computer-readable medium having computer-executable instructions for performing the steps recited in claim 1.

10. A method for preserving attributes of objects in a file when the file is opened in a different environment than that in which the file was originally created, comprising the steps of:

(a) temporarily storing attributes of the objects included in the file when the file is opened in the different environment, including attributes of the objects in the file that are not recognized in the different environment;

(b) enabling changes to be made to the file, including adding new objects to the file that have attributes;

(c) merging the attributes of any new objects added by the changes made to the file with the attributes of the objects that were stored, to produce a revised file; and

(d) writing the revised file, said revised file including the attributes of the objects included in the file when the file was created and attributes of any new objects added in accord with any changes made to the file, said file preserving the attributes of the objects remaining in the revised file that were originally created in the file.

11. The method of claim 10, wherein the attributes define a stylistic format of the objects in a document, said style of the file originally created being thus preserved following changes to the file in the different environment.

12. The method of claim 11, wherein an object in the file comprises text and an attribute associated with said object defines a whitespace around the object, said object and its associated attribute being stored as a substring to preserve the attribute.

13. The method of claim 12, wherein the whitespace includes at least one of an indent level and a line spacing applied to the text of the object.

14. The method of claim 11, further comprising the step of applying predefined rules to determine the stylistic format that should be associated as a new attribute with a new object added to change the file, said new attribute being merged with the attributes that were stored when writing the revised file.

15. The method of claim 10, further comprising the step of parsing the file to identify the objects and the attributes associated with each object, producing internal representations of the objects and their attributes that are temporarily stored while the file is open in the different environment.

16. The method of claim 10, wherein the objects include a tag element having attributes that defines leading and trailing whitespace for the tag element.

17. The method of claim 16, wherein the trailing whitespace for the tag element determines an indent level for a subsequent object in the file.

18. The method of claim 16, further comprising the step of automatically determining a set of rules to apply in formatting a style for new objects added to the file as a function of the attributes of objects already included in the file opened in the different environment, to be consistent therewith.

19. A computer-readable medium having computer-executable instructions for performing the steps recited in claim 10.

20. A system for preserving attributes of a persistent object stream in a file that includes at least one object when the file is opened in a different environment than that in which the file was originally created, comprising:

(a) a memory adapted to store data and machine instructions;

(b) a processor coupled to the memory, said processor controlling storage of data in the memory and executing the machine instructions to implement a plurality of functions;

(c) a display on which graphics and text are presented to a user in accord with the machine instructions, said display being controlled by the processor; and

(d) a user input device adapted to enable the user to input data and to control the processor, said plurality of functions implemented by the processor including;

(i) creating a temporary copy of attributes associated with each object in the memory when reading the file in the different environment, said copy including attributes that are unknown to said different environment;

(ii) ignoring any of said attributes associated with each object that are unknown to the different environment when the file is opened;

(iii) enabling the user to enter changes to the file with the user input device after the file has been opened; and

(iv) merging known attributes associated with each object with the copy of the attributes associated with the object, including any attributes that are unknown, when writing the file to the memory.

21. The system of claim 20, wherein objects in the file include text entries having whitespace attributes, and wherein a whitespace attribute that is associated with a text entry is preserved in the copy unless changed while the file is open in said different environment.

22. The system of claim 20, wherein objects in the file include tag entries having whitespace attributes, and wherein a whitespace attribute associated with a tag entry is preserved in the temporary copy unless changed while the file is open in said different environment.

23. The system of claim 20, wherein objects in any class that is unknown in the different environment are preserved in the temporary copy and are ignored in the different environment, but are merged with known objects when the file is written to the memory.

24. The system of claim 20, wherein the attributes for an object that is unknown in the different environment include a function associated with the object that is not recognized in the different environment, but is recognized in the environment in which the object was first added to the file.

25. The system of claim 20, wherein the machine instructions further cause the processor to parse the file to identify the persistent object stream, and to create a different internal representation of the attributes associated with objects in the file for use in the copy that is created.

26. The system of claim 20, wherein the machine instructions further cause the processor to determine attributes of the persistent object stream when the file was opened and apply said attributes to any related new objects that are added to the file while the file is open, so that attributes of the new objects are consistent with those of the persistent object stream.

27. The system of claim 20, wherein changes to the file written to the memory are minimized to insure that the attributes of objects in the file are retained.