How to get a4j:support for just some key press and not for all.

[mettehummel]

I'm using a4j:support event="onkeyup" actionListener="myActionListener" to do some stuff every time a key is pressed. It works fine, but I only want to do my stuff when some keys are pressed and not for all. How do I do that? I was hoping that the actionEvent would contain information about which key was pressed, but I can't seem to find that information. Can I limit the keys in the a4j:support ?

Mette

[bkersten]

Hi Mette,

first of all bad news for direct usage cause AFAIK:

• u can't limit <a4j:support event="onkeyup" .../> for certain keys
• the ActionEvent object passed to your ActionListener method on server side does not contain information on the key pressed

But (if u are not afraid of some lines of JS) u could:

• use the a4j:jsFunction tag to trigger your actionListener
• trigger your own JS function for onkeyup and call the jsFunction defined above if a certain key was pressed

such as:

<a4j:jsFunction name="callMyActionListener" actionListener="myActionListener">

and

function keyUpFunction( event ){
    
     if (  event.keyCode == Event.KEY_TAB
        || event.keyCode == 73                 // e.g. letter "i", JS keyCodes can be found on web
        || event.keyCode == Event.KEY_UP ){

        callMyActionListener();
    }
}

and the onkeyup event for the tag u wanted to use a4j:support for

<h:inputText onkeyup="keyUpFunction" />

Con: some lines of JS

Pro: compared to a server side check within the actionListener of which key was pressed this even reduces traffic and #roundtrips as an ajax request is only triggered if your desired key was pressed.

Regards

Benjamin

[mettehummel]

Solved my problem. Just a small addition was needed of the event as a parameter to the function.

Thanks!

<h:inputText onkeyup="keyUpFunction(event)" />