Contrasting styles of Web UI Development: GWT vs Native JavaScript Roland Schweitzer Weathertop Consulting, LLC Jeremy Malczyk JISAO

GO-ESSP GWT development is like... going to hear a symphony.

GO-ESSP JavaScript development is like... going to have oral surgery.

GO-ESSP 20084

5

6

7 IDE Tools Special “hosted” browser that runs the native Java for development and testing in the IDE Debug client and server in the same IDE Cross-compiler that compiles and optimized the Java into JavaScript targeted to a suite of common browsers Deploys as regular web page with JavaScript references on any Web server

GO-ESSP Extensive Widget Library Many widgets (including maps)‏ Widgets are easy to combine into reusable composite widgets Listeners can “bubble up” clicks through the widget stack so clicks can be handled at the top level

GO-ESSP Reuse Existing JavaScript “Overlay” a Java type on existing JavaScript code Similar in concept to JNI in fact they call it JSNI public class LASDateWidget extends JavaScriptObject { protected LASDateWidget(){} public final native String getDateLo() /*-{ return this.getDateLo(); }-*/;

GO-ESSP Used Date Widgets

GO-ESSP Reuse or adapt AJAX RPC Consume existing XML or JSON server responses Build or adapt services to use GWT RPC It was so easy, I adapted our services to use native RPC Once the serializable container was written I could use it on both the server and the client Didn’t have to use native JavaScript that I am too impatient to understand and didn’t have to parse the JSON into a new client-side object

GO-ESSP Leverage Existing LAS Capabilities AJAX request/responses already available to discover data sets, variables, grids, operations and options Needed to add a way to group “data sets” (a single netCDF file) into collections that and to identify the group as special (candidate for the TimeSeries) interface. group_name = “Channel Islands – Santa Rosa” group_type=”time_series”

GO-ESSP Leverage... Existing tool (with new group parameters) consumes THREDDS catalogs which have collected the netCDF files into logical groupings and returns LAS configuration XML Existing operation and options for plotting time series Can add more from existing operation as needed or add new operations

GO-ESSP Conclusion GWT is more fun than oral surgery!