Methods and systems for processing XML documents

• US 7,134,072 B1
• Filed: 10/13/1999
• Issued: 11/07/2006
• Est. Priority Date: 10/13/1999
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Lovett, Christopher J, Zeng, Nanshan
• Primary Examiner(s): Hong, Stephen
• Assistant Examiner(s): QUELER, ADAM M
• Application Number:
  US09/417,990
• Time in Patent Office: 2,582 Days
• Field of Search: 715/513, 715/530, 707/101
• US Class Current: 715/234
• CPC Class Codes: G06F 40/143 Markup, e.g. Standard Generalized Markup Language [SGML] or Document Type Definition [DTD]
• CPC Class Codes: G06F 40/154 Tree transformation for tree-structured or markup documents, e.g. XSLT, XSL-FO or stylesheets

Abstract

An architecture for processing an Extensible Markup Language (XML) document converts schema elements in the XML document to data type definition (DTD) objects that can be used to validate data elements in the XML document. The architecture utilizes a node factory design in which an XML parser calls one or more node factory interfaces to construct an in-memory tree representation of an XML document. One of the node factory interfaces is a schema node factory, which is a thin layer that receives calls from the parser to build nodes in the tree representation and translates those calls to calls to a schema builder. The schema builder is a table driven interface that converts the schema elements in the XML document into DTD objects. The DTD objects are then used to validate the data elements as belonging to the schema. If valid, the data elements are used to construct the tree representation.

Claims

1. A method for processing an extensible mark up language (XML) document comprising:

parsing the XML document into a stream of schema elements and data elements;

receiving the stream of schema elements using an API;

converting the stream of schema elements into data type definition (DTD) objects;

validating the stream of data elements using the DTD objects; and

if valid, passing the stream of data elements to an application using the API;

wherein the converting step comprises;

obtaining a parameter from a static table; and

calling a function to construct a DTD object based on the schema element, the function constructing the DTD object based on the parameter from the static table.

2. The method of claim 1, wherein the converting further comprises:

calling a method in a first application program interface (API); and

as a result of calling the first method, calling one or more methods in a second API to construct the DTD objects.

3. The method of claim 1, wherein the converting comprises referencing the static table, the static table defining the schema elements and associated functions for processing the schema elements.

4. A computer-readable medium having computer-executable instruction, which when executed by a computer, performs the method of claim 1.

5. The method of claim 1 wherein the function comprises at least one of a function for signaling a new schema is being processed, signaling that an end of a schema has been reached, determining if it is valid to have text in a current position of a schema document, determining if all content for a current schema element has been corrected provided, and creating a DTD content model node for describing a default value.

6. The method of claim 1 wherein the step of calling the function includes:

identifying a new schema element in the static table;

pushing the new schema element onto a stack;

initializing at least one data structure for the new schema element; and

creating an empty DTD object for the new schema element.

7. The method of claim 1 wherein the static table includes an attribute table for providing an attribute of a schema element and wherein the step of calling the function includes parsing the attribute table for an attribute value corresponding to the schema element and calling a function corresponding to the attribute value.

8. The method of claim 1 wherein the static table is organized in a hierarchical arrangement and includes a schema root table at a top of the hierarchical arrangement, the schema root table including a reference to a subordinate table for describing a type of the schema element.

9. The method of claim 8 wherein the subordinate table includes at least one of an element table and an attribute table, the element table including at least one field listing a type of element permitted in the schema element and the attribute table including at least one field listing a type of attribute in the schema and a corresponding function for handling the attribute.

10. The method of claim 9 wherein the static table includes the element table, the element table further referencing at least one function table and wherein the at least one function table contains functions pertaining to node events.

11. The method of claim 1 wherein the converting step comprises:

wherein the function includes;

identifying a new schema element in the static table;

pushing the new schema element onto a stack;

initializing at least one data structure for the new schema element; and

creating an empty DTD object for the new schema element,

wherein the function constructing the DTD object is based on the parameter from the static table and including one of signaling a new schema is being processed, signaling that an end of a schema has been reached, determining if it is valid to have text in a current position of a schema document, determining if all content for a current schema element has been corrected provided, creating a DTD content model node for describing a default value,

and wherein the static table is organized in a hierarchical arrangement including a schema root table at a top of the hierarchical arrangement, an attribute table for providing an attribute of a schema element including at least one field listing a type of attribute in the schema and corresponding functions for handling the attribute, and an element table including at least one field listing a type of element permitted in the schema element, the element table further referencing at least one function table containing a function pertaining to node events,

and wherein the step of calling the function includes parsing the attribute table for an attribute value corresponding to the schema element and calling a function corresponding to the attribute value.

12. A computer implemented with an architecture for processing an extensible mark up language (XML) document comprising:

a parser to parse the XML document into a stream of elements including a stream of schema elements and a stream of data elements;

a converter to convert the stream of schema elements into data type definition (DTD) objects using an API and to validate the stream of data elements using the DTD objects;

wherein the converter further obtains a parameter from a static table and calls a function to construct a DTD object based on the schema element, the function constructing the DTD object based on the parameter from the static table; and

a schema node factory to pass valid data elements to an application using the API.

13. The computer of claim 12, wherein the architecture further comprises a schema builder that utilizes one or more tables to process the elements, the tables containing information defining a schema for the XML data.

14. A client-server system, comprising:

a server;

a client connectable to the server to exchange extensible mark up language (XML) documents;

at least one of the client and the server comprising the computer of claim 12.

15. The computer of claim 12, wherein the architecture further comprises a validation node factory to evaluate whether the data elements comply with constraints set forth in the DTD objects.

16. The computer of claim 12 wherein the converter further identifies a new schema element in the static table, pushes the new schema element onto a stack, initializes at least one data structure for the new schema element, and creates an empty DTD object for the new schema element.

17. A computer implemented with an architecture for processing an extensible mark up language (XML) document comprising:

a parser to parse the XML document into a stream of elements including a stream of schema elements and a stream of data elements;

a converter to convert the stream of schema elements into data type definition (DTD) objects using an API and to validate the stream of data elements using the DTD objects; and

a schema node factory to pass valid data elements to an application using the API;

wherein the converter further obtains a parameter from a static table and calls a function to construct a DTD object based on the schema element including;

identifying a new schema element in the static table;

pushing the new schema element onto a stack;

initializing at least one data structure for the new schema element; and

creating an empty DTD object for the new schema element,

wherein the function to construct the DTD object is based on the parameter from the static table and including one of signaling a new schema is being processed, signaling that an end of a schema has been reached, determining if it is valid to have text in a current position of a schema document, determining if all content for a current schema element has been corrected provided, creating a DTD content model node for describing a default value,

and wherein the static table is organized in a hierarchical arrangement including a schema root table at a top of the hierarchical arrangement, an attribute table for providing an attribute of a schema element including at least one field listing a type of attribute in the schema and corresponding functions for handling the attribute, and an element table including at least one field listing a type of element permitted in the schema element, the element table further referencing at least one function table containing a function pertaining to node events,

and wherein the step of calling the function includes parsing the attribute table for an attribute value corresponding to the schema element and calling a function corresponding to the attribute value.