Sometimes you need to calculate the content of one column based on the content of other columns. Generated columns are just great for accomplishing that. Suppose you have a table with two Integer columns:
Table table = new Table();
table.addContainerProperty("A", Integer.class, 0);
table.addContainerProperty("B", Integer.class, 0);You want a third column with the sum of the previous columns. Here is the code to do that:
table.addGeneratedColumn("A + B", new ColumnGenerator() { @Override public Object generateCell(Table source, Object itemId, Object columnId) { Integer a = (Integer) source.getItem(itemId) .getItemProperty("A").getValue(); Integer b = (Integer) source.getItem(itemId) .getItemProperty("B").getValue(); return a + b; } });
A column generator must implement the generateCell method that returns the value or the UI component to render on the cell...