Use Eclipse RAP to Build Rich Internet Application

It is a pity that I had not heard of Eclipse RAP (Rich Ajax Platform) when last year I developed Grimoires Browser, an Eclipse RCP based client for the Grimoires Service Registry.

RAP has joined the family of Eclipse UI toolkits, as existing ones such as SWT for Windows, SWT for Liunx, and SWT for Mac. In some sense, RAP can be considered as SWT for Web.

RAP is ued to develop Rich Internet Application (RIA). To develop an RAP-based web application, programmers are still working in Java, in SWT, and in JFace. And RAP makes sure the UI is built on top of HTML, JavaScript and Ajax. Remind you something? Yes, GWT. There are some very good introductory articles [1, 2] about RAP on IBM Developer Works.

It is claimed that in a minimal effort, we can transform an existing RCP application to RAP; or we can even build an application which is largely independent of RAP or RCP. So it can run as both a web application and a desktop application.

No doubt, RAP is the way to go to make Grimoires Browser a web application. It will then totally relieve users the pain to install some software on their machine in order to access Grimoires.

Bridge GLUE LDAP schema and GLUE XML schema

GLUE is an information model to describe Grid resources. It has both an LDAP schema and an XML schema as its concrete data models. Usually GLUE data is in LDAP DIT in Grids. I need to read the LDAP data, convert to XML data according to GLUE schema, and then publish into Grimoires registry. What I am doing is:

1. Use JAXB to generate Java bean classes according to GLUE XML schema;
2. Parse GLUE LDAP schema with the help of an ANTLR-based LDAP schema parser, and generate Java code that converts LDAP entries to Java beans using the classes generated in step 1;
3. Use JNDI to read GLUE LDAP DIT, call the code generated in step 2 to create beans that are further serialized to XML (in GLUE schema) by JAXB;
4. Publish GLUE XML to Grimoires through the XMLView interface, which takes the configuration of XSLT between GLUE schema and Grimoires schema.
   

A Toy Language to Handle Grimoires Registry

I created a toy language to handle Grimoires registry using ANTLR. It also has a simple GUI to type and run the script. So I can type something like:

publish business (name="BusinessAA", desc="a business") -> $bk.

publish service (name="ServiceAA", desc="a service",bkey=$bk, wsdl="http://a/b/c.wsdl", address="http://a/b/") -> $sk.

attach metadata (type="http://www.grimoires.org/QoS", value="very good") to service (skey=$sk).

If run this script, it will first publish a business with name and description, and save the business key to a variable $bk, which will later be used in publishing service. It then will publish a service and attach a metadata to the published service.