Write Wrappers (Old) - ecologylab/BigSemanticsWrapperRepository GitHub Wiki

As explained in introduction, wrappers are code blocks that are written in the meta-metadata language to describe the structure of and associated information for extracting and using metadata. Librarians and information curators may author their own wrappers to add new information sources to a collection representation application built-on BigSemantics, without the need of learning programming. Developers may also use wrappers in program to guide presentation of extracted semantics.

This tutorial will guide you through the process of authoring a new wrapper, compiling it into programming language data structures, and running the test program to inspect the metadata extracted using your new wrapper. We will also talk about common problems with wrapper authoring.

Before start, make sure that you have a working development environment set up, and it conforms to the conventional folder layout.

Prior to authoring your own wrappers, you need to set up a development environment using Java and Eclipse. You will author your own wrappers in Eclipse, in the form of XML files, and compile them into code in a target language (e.g. Java or C#) for use.

The core of the meta-metadata language is a cross-language type system that represents semantics in different systems and programming languages, with the support of S.IM.PL. With meta-metadata language, application developers, information curators, librarians, and power users author meta-metadata wrappers to specify data structure, extraction rules, semantic actions, presentation rules, and other aspects of semantics.

Follow the following pages through examples to learn how to write your own wrappers in meta-metadata language:

• data structure definition
• information extraction
• semantic actions
• compiling wrappers
• running MmTest
• common problems with wrapper authoring
• advanced wrapper features

Next, learn about:

• Use extracted metadata in program
• Exchange semantic data across system boundaries
• Use BigSemantics service

For code samples, see this page.