Indexing structured documents

1. A computer-implemented method for indexing structured documents comprising, at a server:

applying a pre-defined rule-set to a plurality of versions of a first document in a plurality of structured documents to extract one or more index-values, the pre-defined rule-set including a plurality of rules, each rule having a distinct rule identifier, each extracted index-value being extracted by a rule in the pre-defined rule set, wherein one or more versions of the first document is concurrently accessible to a plurality of users for collaborative authoring; and

for each extracted index-value, storing in an index-value data structure the extracted index-value, the rule identifier of the rule that extracted the index-value, and information identifying the first document and the respective version of the first document from which the index-value was extracted.

2. The computer-implemented method of claim 1 in which the plurality of structured documents are included in a Web based Distributed Authoring and Versioning (WebDAV) file system.

3. The computer-implemented method of claim 2 in which the WebDAV file system and the index-value data structure are stored in a relational database management system (RDMS).

4. The computer-implemented method of claim 2 in which applying and storing are executed synchronously when generating the first document in the WebDAV file system.

5. The computer-implemented method of claim 2 in which applying and storing are executed asynchronously when generating the first document in the WebDAV file system.

6. The computer-implemented method of claim 1 in which the first document includes an indexing property that matches a stored reference indexing-property selected from the group of document-type, URL, and document-version.

7. The computer-implemented method of claim 1 in which the first document is a markup language document with a markup-language selected from the group of XML, XHTML, and WML.

8. The computer-implemented method of claim 1 in which the index-value data structure is stored as a relational database table.

9. The computer-implemented method of claim 1 in which the plurality of rules included in the pre-defined extraction rule set each are defined by a corresponding XPath expression.

10. The computer-implemented method of claim 1 in which the plurality of structured documents are included in a file system that is processed by a first processor and the steps of applying and storing are executed by a second processor.

11. The computer-implemented method of claim 1 further comprising, at the server:

identifying a plurality of additional documents in the plurality of structured documents; and

repeating the steps of applying and storing for each of the plurality of additional documents.

12. The computer-implemented method of claim 1 , wherein the index-value data structure is entirely generated by applying the pre-defined rule-set to documents in the plurality of structured documents.

13. The computer-implemented method of claim 1 , wherein:

each of the versions of the first document is associated with a distinct document identifier; and

the information identifying the first document and the respective version of the first document from which the index-value was extracted comprises the distinct document identifier of the respective version of the first document from which the index-value was extracted.

14. The computer-implemented method of claim 1 , wherein:

the first document is associated with a document identifier that is common to the plurality of versions of the first document; and

the information identifying the first document and the respective version of the first document from which the index-value was extracted comprises a version-property of the respective version of the first document from which the index-value was extracted and the document identifier.

15. A computer-implemented method comprising, at a server:

applying a pre-defined rule-set to each indexable document in a plurality of structured documents, including applying the pre-defined rule-set to a plurality of versions of an indexable document in the plurality of structured documents, to extract one or more index-values, the pre-defined rule-set including a plurality of rules, each rule having a distinct rule identifier, each extracted index-value being extracted by a rule in the pre-defined rule set, wherein one or more versions of the indexable document is concurrently accessible to a plurality of users for collaborative authoring; and

for each extracted index-value, storing in an index-value data structure the extracted index-value, the rule identifier of the rule that extracted the index-value, and information identifying the respective indexable document and a respective version of the respective indexable document from which the index-value was extracted.

16. The computer-implemented method of claim 15 further comprising, at the server:

identifying each document in the plurality of structured documents that has an indexing property that matches a stored reference indexing-property as an indexable document; and

determining for each indexable document whether the respective indexable document is locked.

17. The computer-implemented method of claim 15 in which the plurality of structured documents are included in a WebDAV file system.

18. The computer-implemented method of claim 15 in which each of the indexable documents is a markup language document.

19. An article comprising:

a storage medium having stored thereon instructions that when executed by a server computer result in the following:

applying a pre-defined rule-set to a plurality of versions of a first document in a plurality of structured documents to extract one or more index-values, the pre-defined rule-set including a plurality of rules, each rule having a distinct rule identifier, each extracted index-value being extracted by a rule in the pre-defined rule set, wherein one or more versions of the first document is concurrently accessible to a plurality of users for collaborative authoring; and

for each extracted index-value, storing in an index-value data structure the extracted index-value, the rule identifier of the rule that extracted the index-value, and information identifying the first document and the respective version of the first document from which the index-value was extracted.

20. A computer program product, tangibly stored on a machine readable medium, for indexing structured documents, comprising instructions operable to cause a server computer to:

apply a pre-defined rule-set to a plurality of versions of a first document in a plurality of structured documents to extract one or more index-values, the pre-defined rule-set including a plurality of rules, each rule having a distinct rule identifier, each extracted index-value being extracted by a rule in the pre-defined rule set, wherein one or more versions of the first document is concurrently accessible to a plurality of users for collaborative authoring; and

for each extracted index-value, store in an index-value data structure the extracted index-value, the rule identifier of the rule that extracted the index value, and information identifying the first document and the respective version of the first document from which the index-value was extracted.