Apache XML Schema not so good

[Week 26]

I've been spending the last few weeks trying to get used to the Apache XML Schema API so that I can begin to extract information from XML Schema files. This is proving quite a bit more complex than I imagined and has brought me way behind schedule.

I've been emailing the developers mailing list in search of support and have received some replies however I am still having problems extracting information. I may have to look into finding a completely different API for this.

Why does this bring me so behind schedule?
There are three main parts to the project:
- Parse XML Schemas and represent them in a GUI (I plan to use JTree)
- Allow the user to select nodes and produce the XPath expression
- Convert this to SQL and send query to a relational database and display
the results to the user.

Unless I can parse files then there is no way I can create the JTree so I need to fix this part before moving on. With other assignment deadlines at the moment this is proving difficult.

JTree Observations and Inital Screenshots

[Week 23]

This is the main screen after the application is launch. For now I've hard coded some dumb data into the JTree for testing. 

To the left of the JTree is the AWT List which is contain the names of schemas loaded into the application

Here we can see one XSD file in the AWT list on the left. Also I've added an event listener to the JTree and made use of the getSelectionPath() method which returns a TreePath object. 

We can see the TreePath object as a string displayed below the application window. It will be these paths that I will later convert to XPath and display to the user.

Commons XML Schema Model

[Week 21]

Commons XML Schema model is a general purpose schema model that can be used when a Java object tree representation of an Xml schema is required. -http://bit.ly/SUxXC

I found this API for processing XML schemas. It sounds like it will be perfect for my needs. Quite busy with continuous assessment projects at the moment. I will continue experimenting with this API as time allows and post back on project updates as soon as possible.

Netbeans, Basic GUI Work & Subversion Setup

[Week 18]

Last year I used Eclipse for my 3rd year project along with a plugin for designing the GUI. I started experimenting with Netbeans in September. I have found it to provide all of the functionality that Eclipse does albeit a few things are in different places, e.g. generating getters and setters for classes. However it does more out the box. The most basic version of Netbeans available for download is only 39MB and includes a graphical GUI builder. Therefore I've been using Netbeans ever since and it proved very useful for my patterns project in semester 1. I will also be making use of Netbeans for my RMI assignment due shortly.

This week I've been trying out various GUI components and deciding on suitable ones for the project. I will post a screenshot as soon as I have some basic functionality working. Anyway I've decided to use a JTree for representing the XML schema to the user. Also I decided an awt List would be handier than a JList. This will be the list of schemas the user has loaded into the application. The user will be able to select a schema from the list and this will update the JTree appropriately. An awt list is handier because of its add(String item) and add(String item, int index) methods. Whereas with JList a data model must be constructed and this is not needed for this list. Of course a JTree will need a data model but this is worth constructing for the schema and the task of doing this will be delegated to a different class.

Finally I've setup a subversion repository for my project on my redbrick account and synchronised it with the project in Netbeans. I ran into a few connection issues. This was fixed after I setup the DCU proxy in Netbeans. Using subversion will no doubt be invaluable in keeping track of project changes with the ability to compare source files with previous versions and revert if need be.

This coming week I plan to continue with GUI development and research into XML schema parsing.

Adobe AIR / Flex

[Week 16]

Been playing around with Adobe AIR and Flex the past week. I'm trying to find effective GUI libraries for the project. Flex is very nice and quite powerful. As with all new things there is a little learning curve though! I'm still getting used to the components. I have learned that it may not be possible to integrate an Adobe AIR application with Java unless I used web services, ie. JSPs, tomcat server etc. 

Therefore this week I'll start researching Swing/AWT libraries for this project. They might not be as easy on the eyes but may be better to stay in familiar ground for now until I get the basics working.