System and method for future-proofing devices using metaschema

• US 20060155725A1
• Filed: 11/29/2005
• Published: 07/13/2006
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Foster, Peter Reeve, Brook, John Charles, Eke, Nigel David Peter
• Granted Patent: US 7,882,149 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/80 of semi-structured data, e.g. markup language structured data such as SGML, XML or HTML content-based retrieval of web data G06F16/95
• CPC Class Codes: G06F 16/88 Mark-up to mark-up conversion conversion for visualization in web browsing G06F16/9577

Abstract

Disclosed are arrangements which seek to update schemas in a controlled manner so that a device (3710) or service can accurately parse documents conforming to a new version of a schema (3724, 3734) without the need for translation services or extra information within the document to provide guides for translation. One embodiment provides a “best-effort” attempt to process documents of an unknown schema, based on a defined similarity threshold, instead of rejecting such documents as being invalid. The arrangements disclosed seek to provide a satisfactory output from an input document that conforms with an unexpected schema. A method for constraining evolution of a schema associated with a markup language includes the steps of defining the schema and defining a metaschema associated with the schema. The metaschema provides rules for valid changes to the schema.

Claims

1. A method for performing schema-validation of a document, said method comprising the steps of:

defining a schema;

defining a set of constraining rules associated with said schema, said set of constraining rules identifying at least one valid change for at least one of an attribute and an element of said schema;

parsing said document using a rule-based parser associated with said set of constraining rules; and

determining a similarity score for said document with respect to said schema, based on said parsing.

2. The method according to claim 1, wherein said similarity score is based on matched expressions for at least one element or attribute in said schema.

3. The method according to claim 1, comprising the further step of:

mapping said document into a conformant document based on the similarity score and a control threshold.

4. The method according to claim 1, wherein said set of constraining rules is included within said schema.

5. The method according to claim 1, comprising the further step of:

defining a metaschema associated with said schema, said metaschema including said set of constraining rules.

6. The method according to claim 1, comprising the further step of:

allocating, in said set of constraining rules, a rule set for one or more elements and attributes in said schema, each said rule set identifying whether an associated element or attribute is required.

7. The method according to claim 6, wherein each said rule set has an associated priority and distance value.

8. The method according to claim 1, wherein said at least one valid change is selected from the group consisting of rename, relocate, and retype.

9. The method according to claim 1, comprising the further step of:

comparing said similarity score against a threshold to determine validation of said document.

10. The method according to claim 1, comprising the further step of:

embedding rule sets in said document to update said set of constraining rules.

20. The method according to claim 2, further comprising the step of:

mapping said document into a conformant document based on the similarity score and a control threshold.

21. The method according to claim 2, wherein said set of constraining rules is included within said schema.

22. The method according to claim 3, wherein said set of constraining rules is included within said schema.

23. The method according to claim 2, further comprising the step of:

defining a metaschema associated with said schema, said metaschema including said set of constraining rules.

24. The method according to claim 3, further comprising the step of:

defining a metaschema associated with said schema, said metaschema including said set of constraining rules.

11. A device for performing schema validation of a document, said device comprising:

a rule-based parser for parsing said document, said rule-based parser being associated with a set of constraining rules associated with a defined schema, said set of constraining rules identifying at least one valid change for at least one of an attribute and an element of said schema; and

means for determining a similarity score for said document with respect to said schema, based on said parsing.

12. A computer program product having a computer readable medium having a computer program recorded therein for performing schema-validation of a document, said computer program product comprising:

computer program code means for defining a schema;

computer program code means for defining a set of constraining rules associated with said schema, said set of constraining rules identifying at least one valid change for at least one of an attribute and an element of said schema;

computer program code means for parsing said document using a rule-based parser associated with said set of constraining rules; and

computer program code means for determining a similarity score for said document with respect to said schema, based on said parsing.

13. A method for constraining evolution of a schema associated with a markup language, said method comprising the steps of:

providing said schema; and

defining a metaschema associated with said schema, said metaschema providing rules for valid changes to said schema.

14. The method according to claim 13, wherein said valid changes are selected from the group consisting of rename, relocate, and retype.

15. The method according to claim 13, comprising the further steps of:

compiling said metaschema into a device;

parsing a document received by said device using the compiled metaschema to identify the presence of required data items; and

determining a schema-validation of said received document.

16. The method according to claim 15, wherein said schema-validation is determined based on the number of identified data items.

17. A method of performing schema validation on one or more documents, said method comprising the steps of:

defining a schema theme;

providing at least one markup language schema associated with said schema theme;

defining a set of rules associated with said schema theme, said set of rules establishing how each said schema relates to said schema theme;

parsing each said document using a parser associated with said set of rules; and

determining a similarity score for each said document with respect to said schema based on said parsing.

18. The method according to claim 17, comprising the further step of:

ranking said documents according to said determined similarity scores.

19. A computer program product having a computer readable medium having a computer program recorded therein for validating documents, said computer program product comprising:

computer program code means for defining a schema theme;

computer program code means for providing at least one markup language schema associated with said schema theme;

computer program code means for defining a set of rules associated with said schema, said set of rules establishing how said schema relates to each said schema theme;

computer program code means for parsing said document using a rule-based parser conformant with said schema and associated with said set of rules; and

computer program code means for determining a similarity score for said document with respect to said schema for at least one of said schema themes, based on said parsing.