OOXML Framework

The OOXML framework targets the import of OfficeOpen XML documents and tries to do as much of this work automatically. By reading the OOXML schema files and producing a parser skeleton it removes the necessity of managing XML contexts manually.

Design

The design of the new OOXML import framework adds a layer of abstraction on top of a push parser. The events for start tags, end tags or text are handled by the new import framework. Rules for this are derived directly from the specifications. These introduce the concept of complex types and simple types. Very simplified a complex type describes parent-child relationships between elements while simple types describe the types of attribute values. It is the task of the framework to do the translation from elements to complex types and preprocess attribute values according to their simple types. This has several advantages over a classical bare-bones push parser:

• There are a few cases where the same element is mapped to different complex types. This disambiguation is now done automatically by the framework.
• The callbacks are more readable because they are directly tied to a complex type which can be looked up in the spec.
• Much of the low level processing is now done automatically and therefore
  • does not obfuscate the import code
  • is less error prone
  • requires the developer to write less code
  • is potentially faster

The connection between OOXML parser and importer callbacks is done via a domain specific language (DSL). This, together with the automatic preprocessing of the specifications, allows the development of automatic analysis and processing programs. These allow us to

• analyze how much of the specification is handled by import callbacks and thus
• tell us which complex types and attributes still need more work
• compile documentation contained in the document code
• track progress of the development
• improve the development process by providing means to e.g. search for the implementation of a certain element or complex type
• add logging and debugging functionality on demand

Implementation

The OOXML framework has its home in the main/ooxml module. The implementation work is tracked by issue 125035.

In source/framework you can find these framework components:

SchemaParser

(under development) A parser for schema files and a parser generator for the actual OOXML parsers (yet to come).

JavaOOXMLParser

(under development) A demonstration parser of OOXML documents that is based on parser tables created by the SchemaParser. Its main purpose is to test the ouput of the SchemaParser. It is not inteded as a runtime component of OpenOffice.