Blog do projektu Open Source JavaHotel

sobota, 30 lipca 2016

New features in Jython MVP framework

I started playing around with Vaadin Gwt Polymer and decided to implement this feature in my Jython MVP framework. The source code is available here, show demo version can be launched through this address (it could take several minutes until Google App Engine instance is activated). Important : does not work properly in Firefox, tested with Chrome only.
New features are consumed in two ways:
Polymer implementation

XML definition
In order to activate Polymer rendering "polymer" attribute should be added. Widgets implemented so far: menu, combo (PaperDropdownMenu), main panel, editing. A list is not implemented yet. A date picker is implemented by standard GWT DatePicker widget, I was unable to find Polymer equivalent.
Dynamic UI Binder
Polymer rendering described above comes with one obstacle. In order to give access to all Polymer properties, it would be necessary to extend the xml definition by a huge number of additional attributes mapping to appropriate Polymer properties. It is resolved by GWT UiBinder which is not applicable for Jython MVP framework because UI Binder is resolved statically, during compilation. So I decided to develop my own UI Binder implementation, resolved dynamically. In a sample application, I implemented several Paper Elements from Vaadim GWT Polymer show case.
GWT UI Binder format is not mutually intelligible with MVP Jython UI Binder format. But both share the logic, I found quite easy to adapt UI Binder from Vaadim show case for a  sample application. An example of UIBinder for above dialog is available herefieldid attribute binds UIBnder element with corresponding field or button element, like GWT UIBinder ui:field attribute.
Java code for dynamic UI Binder is here. Of course, it is not possible to use reflection in GWT context, so the only solution is a painstaking manual setting of all corresponding attributes.
Next steps
Implementing all samples from GWT Vaadin Polymer show case.