Describes SDXL and how to use this language to serialize schedule data.

JViews Gantt allows you to serialize schedule data to Schedule Data Exchange Language (SDXL) files. Use the classes in ilog.views.gantt.xml. You can find a description of the SDXL format in Content and structure of an XML data file in Using the Designer. You can also find the DTD specification of the SDXL format in Document type definition for SDXL.

You can find the DTD file in:

<installdir>/jviews-gantt/data/sdxl.dtd

The Gantt chart ( IlvGanttChart) and the Schedule chart ( IlvScheduleChart) are designed to visualize and to edit schedule data in a JViews Gantt model ( IlvGanttModel). Users of the Gantt chart and the Schedule chart need first to save their schedule data and then to exchange the schedule data with other users.

SDXL is an application of W3C XML. It is designed to meet the following needs:

Scenarios of how SDXL can be used

Since SDXL is a flexible XML application, its usage is not limited in scope.

However, to give a general idea, imagine the following scenarios:

API for reading and writing SDXL

The following figure shows that the ilog.views.gantt.xml contains all the classes that make it possible to serialize schedule data to SDXL files:

The previous figure shows how the ilog.views.gantt.xml package can serialize schedule data contained in an IlvGanttModel to SDXL files. The ilog.views.gantt.xml package is based on java.io and JAXP (Java™ API for XML Processing) since it has to use java.io APIs and JAXP to read and write SDXL files.

To be able to use the ilog.views.gantt.xml package, you need both:

To use these libraries, you need a thin and lightweight API that provides a standard way to seamlessly integrate any XML-compliant parser with a Java application. JViews Gantt comes with the Apache™ Xerces parser implementation.

The ilog.views.gantt.xml package is designed to serialize schedule data defined by the following classes:

If your Gantt data model is exclusively defined by these classes, the ilog.views.gantt.xml package contains all the classes you need to serialize your schedule data. The following table lists by level the readers and writers available in the package. An interface is given for each reader or writer. This interface defines the functionality the reader or the writer must implement. One of the benefits of using interfaces is that you can interchange readers or writers that implement the same interface. This makes the package flexible and customizable.

For each reader and writer, the package provides two default implementations. The “simple” implementations read and write the default data model classes, while the “general” implementations read and write the data model classes that support user-defined properties.

These can be used as-is.

The readers and writers are arranged by levels. Level 1 is the lowest level and level 3 is the highest. In most cases, the readers and writers of level N are based on the readers and writers of level N-1. For example, to read a Gantt data model from a document, the IlvGanttDocumentReader (level 2) uses element readers (level 1), that is, IlvSimpleActivityReader, IlvSimpleResourceReader, IlvSimpleReservationReader, and IlvSimpleConstraintReader.

Customizing readers and writers

The default readers and writers provided by JViews Gantt are sufficient to serialize default Gantt data models. If you created a customized Gantt data model, you need to customize the default readers and writers in order to serialize the customized schedule data. All level readers and writers are customizable. You can customize them either by creating subclasses of the default readers and writers implemented, or by writing you own readers or writers that implement the reader or writer interfaces.

This section shows how to use the main classes of the ilog.views.gantt.xml package. You will learn how to write an IlvGanttModel to an SDXL file and then how to read back an IlvGanttModel from an SDXL file.

Two examples show how to serialize schedule data:

To write the contents of an IlvGanttModel to an SDXL file, follow these recommended stages:

Creating an org.w3c.dom.Document

This section shows you how to use the javax.xml.parsers package to create an org.w3c.dom.Document instance. This is one of many ways of creating document objects. You can, of course, use other ways.

To create a new org.w3c.dom.Document instance:

See

for a concrete implementation.

Creating an IlvGanttDocumentWriter

Use the ilog.views.gantt.xml package to create an instance of IlvGanttDocumentWriter. Then the document writer is ready to write an IlvGanttModel to a document.

The IlvGanttDocumentWriter constructor takes a locale as argument that affects how dates are serialized. In the example the document writer is configured to use the current locale.

To create a new IlvGanttDocumentWriter instance:

Writing a Gantt data model to a document

The IlvGanttDocumentWriter has a method called writeGanttModel.

To write your Gantt data model:

The document argument is the document object you created in Creating an org.w3c.dom.Document. The argument yourGanttModel is the IlvGanttModel you want to write to the document.

Creating an output stream

You can use the java.io package to create an OutputStream. This is one of many ways of creating output streams. You can, of course, use other ways.

To create an OutputStream instance:

The argument filename is the name of the SDXL file you want to write to.

Creating a stream writer

After creating the OutputStream, you need a utility class that helps you write the document to the stream. The ilog.views.gantt.xml package provides a stream writer named IlvGanttStreamWriter. You can directly create an instance of this class and use it to write your document. The stream writer is ready to write a document object to an OutputStream.

To create an OutputStream instance:

Writing a document to an output stream

Now that you have the OutputStream instance and the document, you can write your document to the OutputStream object.

To do this:

Your IlvGanttModel is written to an SDXL file.

Change the itemized list back to a numbered list in XML.

To read the contents of an SDXL file to an IlvGanttModel, follow these recommended stages:

These stages are seen in more detail in the subsequent sections.

Creating an input source

You can use your XML Java API to create an InputSource instance for the SDXL file you want to read. This section presents one of many ways of creating input sources. You can, of course, use other ways.

To create an InputSource instance for the SDXL file you want to read:

The input source is ready to be parsed by your XML parser.

Parsing an input source

The DocumentBuilder provided by your XML Java API can parse an input source. You can create an instance of the builder and use it to parse the input source.

To parse an input source:

Now you need an IlvGanttDocumentReader instance to read the document.

Creating an IlvGanttDocumentReader

The ilog.views.gantt.xml package provides the IlvGanttDocumentReader class.

To create an instance of this class:

The document reader is ready to read a document.

Reading a Gantt data model from a document

The IlvGanttDocumentReader class has a method called readGanttModel. You can call this method to read a JViews Gantt model from a document. Before reading the document you must create a target IlvGanttModel to receive the schedule data.

To read a Gantt data model from a document:

The document argument is the document object you created in the previous step.

Your IlvGanttModel has now been read from an SDXL file.

Exceptions might be encountered during the reading of the document. The exceptions are reported by IlvGanttReaderException objects. The following example shows how to handle such exceptions.