Iterate all cells of a Vaadin 8 Grid

For a generic export of a grid I need to iterate all the cells. In Vaadin 7 I did that by getting all the Items from the container and using all the columns to get the values of the cells and converting them.

Vaadin 8 completely changed the underlying datastructures and I can’t find a way to iterate all the cells.
Through the grids DataProvider i can get all the objects of the Grid. But I can’t find a way to get the value of a cell using the Column. The valueProvider of the Column does exactly what I want, but I can’t find a good way to access it.

Getting data out of Vaadin Widget seems to be a lot harder with Vaadin 8. You need to get the DataProvider and call fetch with “getAll”-Query. In Vaadin 7 it was a easy getItemIds(). But maybe it is just me feeling like I just started with Vaadin.

We have the same problem.
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