How to add "onchange" SimpleAttributeModifier to DropDownChoice in Apache Wicket

Question

I want to run a particular javascript when selection is changed in the drop down choice, so I added a simple attribute modifier like this :

ddc.add(new SimpleAttributeModifier("onchange", "calc();"));

But if I do this, it completely overrides the wicket onSelectionChanged() method. I need a way to perform both.

Thanks

score 4 · Answer 1 · answered Mar 16 '15 at 17:52

4

Use an OnChangeAjaxBehavior for this like this:

    ddc.add(new OnChangeAjaxBehavior() {

        @Override
        protected void onUpdate(AjaxRequestTarget target) {
            target.appendJavaScript("calc();");
        }
    });

answered Mar 16 '15 at 17:52

Robert Niestroj

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score 2 · Accepted Answer · answered Mar 16 '15 at 12:21

2

You could use an AttributeAppender

ddc.add(new AttributeAppender("onchange", "calc();", " "));

The last argument is the separator used.

answered Mar 16 '15 at 12:21

thg

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yeah but i find the answer by Robert Niestroj more elegant, please accept one of the answers as the solution, so others know what worked. – thg Mar 20 '15 at 10:45
I like the first one because it's just one line :D – Soumitri Pattnaik Apr 08 '15 at 10:12

How to add "onchange" SimpleAttributeModifier to DropDownChoice in Apache Wicket

2 Answers2