IT блог

I’m going to tell about my experience with add-on page. First of all, this page contains outdated code examples, but that’s only the start of the list.

If you reached this article, you most likely face one of these errors, and trying to get rid of one, get another: «variable used in lambda expression should be final or effectively final», «variable may be not initialized», «cannot assign a value to final variable». For my explanation I will use vaadin’s Window.

You probably have already tried out filtering feature in your vaadin project if you reached this article. Let’s understand how to get the list of items left in grid after filtering got applied.

Actually, the task can be split in two subtasks: — retrieving offset in the form which Vaadin can provide (integer number of milliseconds); — formatting it so that we could construct ZoneId.

If you compose a sophisticated application with vaadin, you may face an interesting issue: values in the grid got updated (say, via HTTP) and you can see them in the corresponding rows and columns, but you can’t read the actual values when selection listener gets triggered. I will tell how to workaround this issue.

So, you want to enable in your vaadin app automated authentification based on request params. The right location for this functionality is your instance of com.vaadin.ui.UI class — here the decision is made which view to show. If the provided for authentification data is incorrect or incomplete, then we will show login view. If the […]