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develop new component
I would like to develop my own vaadin component. Les's say it will be quite sophisticated slider to set values, period etc.
How can I start? Can you recomend me some examples/tutorials? Sjoud I do it in Java or JS?
If you use an IDE (like Eclipse) you can use Right Click -> New -> Other... -> Vaadin --> Vaadin Widget to get a fully fledged widget structure including RPCs, States, Connector, .... and also a Widgetset if you don't have one already. If you want to create a JS Component instead you could still use this structure but change it (although you would have to change a lot).
There isn't really a general "better" way. It just comes down to personal preference.