XML streaming transformer

• US 20040034830A1
• Filed: 08/16/2002
• Published: 02/19/2004
• Est. Priority Date: 08/16/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: Commerce One Operations Incorporated (Proactis Holdings Plc)
• Inventors: Fuchs, Matthew, Zhu, Changyi
• Granted Patent: US 7,721,202 B2
• Time in Patent Office: Days
• US Class Current: 715/501.1
• CPC Class Codes: G06F 16/84 Mapping; Conversion
• CPC Class Codes: G06F 16/88 Mark-up to mark-up conversion conversion for visualization in web browsing G06F16/9577
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06F 16/986 Document structures and storage, e.g. HTML extensions
• CPC Class Codes: G06F 40/143 Markup, e.g. Standard Generalized Markup Language [SGML] or Document Type Definition [DTD]
• CPC Class Codes: G06F 40/149 Adaptation of the text data for streaming purposes, e.g. Efficient XML Interchange [EXI] format
• CPC Class Codes: G06F 40/151 Transformation
• CPC Class Codes: G06F 40/154 Tree transformation for tree-structured or markup documents, e.g. XSLT, XSL-FO or stylesheets
• CPC Class Codes: G06F 40/186 Templates
• CPC Class Codes: G06F 40/221 Parsing markup language streams streaming G06F40/149
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

The present invention includes devices and methods to specify a document transformation and to transform a document in a streaming mode, without building a full object tree in memory representing the document. Particular aspects of the present invention are described in the claims, specification and drawings.

Claims

1. A method of transforming a document, including:

receiving events in a stream, including a plurality of element start-events, input events and element end-events;

responding to an element start-event for an element by matching the element to a named template and activating the named template or, lacking a match, by treating the element as content of a parent element;

responding to an element end-event for a current element using a matching named template, if any, including;

responsive to instructions in the matching named template, outputting at least some of literal text or input events corresponding to the current element;

clearing the input events corresponding to content of the current element; and

deactivating the matching named template.

2. The method of claim 1, wherein the events in the stream correspond to an electronic commerce document.

3. The method of claim 1, wherein the events in the stream correspond to a document comprising character data encoding text characters and markup data identifying sets of storage units according to a logical structure of the document.

4. The method of claim 1, wherein the events in the stream correspond to an electronic commerce document comprising character data encoding text characters and markup data identifying sets of storage units according to a logical structure of the electronic commerce document.

5. The method of claim 1, wherein a plurality of the named template instances are stored together in a templates source.

6. The method of claim 2, wherein a plurality of the named template instances are stored together in a templates source.

7. The method of claim 3, wherein a plurality of the named template instances are stored together in a templates source.

8. The method of claim 1, wherein responding to the element start-event further includes activating one or more variables in a scope corresponding to the named template and responding to a corresponding element end-event further includes deactivating the variables.

9. The method of claim 3, wherein responding to the element start-event further includes activating one or more variables in a scope corresponding to the named template and responding to a corresponding element end-event further includes deactivating the variables.

10. The method of claim 7, wherein responding to the element start-event further includes activating one or more variables in a scope corresponding to the named template and responding to a corresponding element end-event further includes deactivating the variables.

11. The method of claim 8, wherein responding to the element end-event corresponding to the named template further includes processing logic instructions to manipulate the variables.

12. The method of claim 11, wherein the logic instructions optionally include substring and concatenation.

13. The method of claim 11, wherein the logic instructions optionally include if and choose flow control operators.

14. The method of claim 11, wherein the logic instructions optionally include if, chose, when, otherwise and for-each flow control operators.

15. The method of claim 1, wherein responding to the element start-event further includes, in response to an instruction associated with the matching named template, creating a tree representation of the element and sub-elements within the scope of named template.

16. The method of claim 13, wherein responding to the element start-event further includes, in response to an instruction associated with the matching named template, initiating creation of a tree representation of the element and sub-elements within the scope of named template.

17. A computer-implemented method of transforming a document, including:

receiving events in a stream, including a plurality of element start-events, input events and element end-events;

responding to an element start-event for an element by matching the element to a named template and activating the named template and variables, if any, in a scope corresponding to the named template;

responding to a nested element start-event by matching the nested element to an additional named template and activating the additional named template and variables, if any, in a scope corresponding to the additional named template or, lacking a match, by treating the nested element as content of the parent element;

responding to input events according to instructions in a most recently activated named template, wherein the instructions optionally include assigning input to one or more of the variables;

responding to an element end-event by processing the corresponding named template, if any, including

processing instructions in the named template, wherein the instructions optionally include manipulating the variables and outputting at least some of literal text and the variables;

clearing the variables in a scope of the corresponding named template; and

deactivating the corresponding named template.

18. The method of claim 17, wherein the events in the stream correspond to an electronic commerce document.

19. The method of claim 17, wherein the events in the stream correspond to a document comprising character data encoding text characters and markup data identifying sets of storage units according to a logical structure of the document.

20. The method of claim 17, wherein the events in the stream correspond to an electronic commerce document comprising character data encoding text characters and markup data identifying sets of storage units according to a logical structure of the electronic commerce document.

21. The method of claim 17, wherein a plurality of the named template instances are stored together in a templates source.

22. The method of claim 18, wherein a plurality of the named template instances are stored together in a templates source.

23. The method of claim 19, wherein a plurality of the named template instances are stored together in a templates source.

24. The method of claim 17, wherein responding to the element end-event corresponding to the named template further includes processing logic instructions to manipulate the variables.

25. The method of claim 24, wherein the logic instructions optionally include substring and concatenation.

26. The method of claim 24, wherein the logic instructions optionally include if and choose flow control operators.

27. The method of claim 24, wherein the logic instructions optionally include if, chose, when, otherwise and for-each flow control operators.

28. The method of claim 17, wherein responding to the element start-event further includes, in response to an instruction associated with the matching named template, creating a tree representation of the element and sub-elements within the scope of named template.

29. The method of claim 26, wherein responding to the element start-event further includes, in response to an instruction associated with the matching named template, creating a tree representation of the element and sub-elements within the scope of named template.

30. A memory utilization strategy while performing a transformation on an XML document, including:

loading a template including one or more subtemplates;

processing a event stream from an input source, including repeatedly matching a subtemplate to a start-event in the input source;

buffering an input stream until an end-event matched to the start-event is received; and

processing instructions in the subtemplate to transform the buffered input stream, outputting results of the processing and releasing for reuse memory used for the buffering and the processing.

31. The method of claim 30, wherein matching the subtemplate to the start-event further includes activating one or more variables in a scope corresponding to the subtemplate and releasing for reuse further includes deactivating the variables.

32. The method of claim 30, wherein the logic instructions optionally include substring and concatenation.

33. The method of claim 30, wherein the logic instructions optionally include if and choose flow control operators.

34. The method of claim 30, wherein the logic instructions optionally include if, chose, when, otherwise and for-each flow control operators.

35. The method of claim 30, wherein the logic instructions optionally include invoking user custom extensions.

36. The method of claim 35, wherein the user custom extensions are written in a Java programming language.

37. The method of claim 30, further including, prior to processing the subtemplate, invoking at least one additional handler to pre-process the input stream.

38. The method of claim 30, wherein the outputting of results includes invoking at least one additional handler to further process the results of processing the subtemplate.

39. The method of claim 30, wherein matching the subtemplate to the start-event further includes, in response to an instruction associated with the subtemplate, creating a tree representation of the element and sub-elements within the scope of the subtemplate.