Event handling with JSF

Hi Everybody,
I have a question about event handling and I am just wondering if I can do the following with JSF.
I have two HTML dropdown lists A and B. When ever a value changes in list A, based on the selected value, list B has to be populated. Is it possible to do with JSF? Can you guys give me pointers where some code samples may be available?
Cheers!
Krish

Take a look at the JSF Value-Changed Listener sections

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C# control event handling with javascript

How can I get javascript to execute for "onchange" / "OnSelectedIndexChanged" event instead of a CodeBehind method? I think "OnSelectedIndexChanged" event has to be handled by CodeBehind; but how can I replace that (or onchange) with
a javascript event handler?
I have the following in my xyz.ascx file:
<asp:DropDownList ID="ddlTypeCar" CssClass="BatsRefAddressTypes" runat="server"
                  onchange="javascript: testAlert();"
                  OnSelectedIndexChanged="ddlTypeCar_SelectedIndexChanged"
                  AutoPostBack="True" />
I could not get the javascript to execute, even though I removed OnSelectedIndexChanged="ddlTypeCar_SelectedIndexChanged" and/or set AutoPostBack="false".
Additionally, I tried added the following in xyz.ascx.cs Page_Load() method.
ddlTypeOfAddress.Attributes.Add("onchange", "javascript: testAlert();");
which didn't help.
Thanks for your help in advance.

Hi,
you can control client events instead of server events with javascript
look this url for more information
http://www.w3schools.com/js/js_events.asp
Regards

Registering event handler with preloader

As you can see from the code below, I have an application
with a custom preloader designated in the Application tag.
I would like the preloader to be able to receive a message
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mx.core.Application.application is null in my preloader. Is there
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I would GREATLY appreciate any help with this! I've been
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Thanks!
Moshe

Thank you Nayan..
BR
Aliye

Event Handling with Java API.: Adding to a hierarchy table throws 2events

I´m having some problems with the event handling. I´ve registered a Class with extends AbstractDataListener as EventListener. When there are changes in the product hierarchy table, some extra work should be done. However if i add a new record into the hierarchy, two events are fired.
DEBUG DataEventListener.java:123 - Added:Development;PRODUCT_HIERARCHY;R17;Getra?nke, SEW
DEBUG DataEventListener.java:123 - Added:Development;PRODUCT_HIERARCHY;R17;32 Zoll, B&R
DEBUG DataEventListener.java:123 - Added:Development;PRODUCT_HIERARCHY;R18;56 Zoll, Lenze
DEBUG DataEventListener.java:123 - Added:Development;PRODUCT_HIERARCHY;R18;20 Zoll, allgemein
In this case, i added the records "32 Zoll, B&R" and then "20 Zoll, allgemein". As you can see in both cases two events are fired and the first event seems to come with wrong data. The reported id for the newly created record is R17. For the logging, i did lookup the entry in the hierarchy table by id and use the displayvalue of the record. But the first event always shows the displayvalue from some already existing entry.
How can i avoid duplicate events or if this is not possible, how i can recognize that the display value of the first event is not valid.

I have not tetsted it yet, because I'm waiting for my server to be updated, but SAP told me that the API version 5.5.42.67 should fix the problem.
Thanks for your post.

Event handling with button

Hi All,
I am trying to write an event handling on my button, but i seem dont know where to start from. My code are below:
import java.net.*;
import java.io.*;
public class ReadWrite
public static void main(String[] args) throws Exception {
URL myLocalhost = new URL("http://localhost/Write.pl");
URLConnection myURL = myLocalhost.openConnection();
BufferedReader myBR = new BufferedReader(
new InputStreamReader(
myURL.getInputStream()));
String inputLine;
while ((inputLine = myBR.readLine()) != null)
System.out.println(inputLine);
myBR.close();
I want to write a code with a button to run the above code.
Could you please advise?
Thank for any consideration you may give me.

here's the code to read a file, modify for your url connection
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
class Testing extends JFrame implements ActionListener
public Testing()
    setLocation(400,300);
    setSize(200,100);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    JPanel panel = new JPanel();
    JButton btn = new JButton("Read/Write");
    btn.addActionListener(this);
    panel.add(btn);
    getContentPane().add(panel);
public void actionPerformed(ActionEvent ae)
    BufferedReader myBR = null;
    try
      myBR = new BufferedReader(new FileReader("Test.txt"));
      String inputLine;
      while ((inputLine = myBR.readLine()) != null)
        System.out.println(inputLine);
      myBR.close();
    catch(Exception e){e.printStackTrace();}
public static void main(String args[]){new Testing().setVisible(true);}
}

Event Handler with parameters

I am to create a generic event handler ro process XML
returned from the server. Its name is this code is "loadFormData".
Here is my code:
var params:Object = new Object();
params.requesttype = 'send';
params.datarequest = 'xml';
params.methodexecute = 'mProcessFileRequest';
params.formname = "FileIdAction";
params.fileid = parentApplication.cboFileList.id;
var t:loadFileData = new loadFileData();
xmlModuleData.addEventListener(ResultEvent.RESULT,
t.loadFormData(ResultEvent, frmGeneral));
var r:runXML = new runXML();
r.getXMLData(xmlModuleData, params);
It would work if I dont send any parameters to
t.loadFormData. But then it is not a generic solution. Is it
possible to send parameters to a callback function?
Thanks

Thanks Charlie
Liao
and congrats to all :-)
* Charlie,
is there a new "Auto Spam Filter"?
[Personal Site] [Blog] [Facebook]

Event handling with UIScrollView and it's subview

Hi,
I have a UIScrollView and inside it a UIImageView. I have a lot of difficulities to handle the events with these two views. Here is what I want to do:
If it is a multi-touch event (event.allTouches.count > 2), I want the UIScrollView to handle the event, i.e Zoom in/out and pan. If it a single touch event (event.allTouches.count == 1), I want the UIImageView to handle the event.
Could you please tell me how to do this?
Thank you very much.
ff

Take a look at the JSF Value-Changed Listener sections

Event handling in JSF

Hi
I have come across a scenario where i need to open a JSF page based on a key press event.
scenario -
if the user clicks on 'F1' key a Help page (a jsf help page with respect to our application) should open. its the same way windows opens help page on click of 'f1'.
Can some body provide any direction?

For starters:
1) Java/JSP/JSF runs at the server machine.
2) Java/JSP/JSF generates and produces a HTML/CSS/JS page.
3) Server machine sends HTML/CSS/JS page to the client machine.
4) Client retrieves HTML/CSS/JS and displays HTML/CSS and runs JS.
So when you want to capture keys in the client side, you need to look for the solution in the HTML/CSS/JS corner. HTML is a markup language, it can't do anything for you. CSS is a styling language, it can't do anything for you. JS (Javascript) is a scripting languate which can intercept on client events, so it's the only which can be of means for you.
Google "javascript capture function keys" or something smart like that for answers. Otherwise better try a javascript forum in the case you stucks.

Event Handler with Internal Loops

Hi...
I'm trying to update a basic program to handle control events more efficiently. The program needs to perform the following functions on start button press:
1) Import data file and parse instrument settings from multiple (X) rows
2) Perform loop with case for each row changing input settings, the read test equipment, and store data in new output data file
I've looked at producer/consumer example and the continuous measurement and logging example, but not sure if either (or none) of the following two options is the best way to handle the looping from the file...
A) Use events to trigger looping for all input cases within a consumer (I've had a problem with this due to not being able to terminate the loop within the consumer with an abort button)
B) Make the consumer only a single data acquisition and load loop inputs as queues and generate output queues to be handled by another parallel logging loop
Any advice?

Hi bripple,
Based on what you've described above, a Producer/Consumer Design Pattern (Events) might work. There is a template for this design pattern that ships with LabVIEW which you can access by going to File > New > VI > From Template > Frameworks > Design Patterns. When the user clicks the start button on your front panel, you can queue up a command that will trigger your consumer loop to read the file and loop over each instrument setting. Within that loop, you should be able to queue up additional events corresponding to each instrument setting and reading.
In terms of error handling, you can conditionally stop a loop if you detect an error. If your user decides to push a button on the front panel to stop the entire process, you can use Enqueue Element at Opposite End to put a stop command at the beginning of the queue. When your consumer loop encounters this event, it can flush the queue and do any cleanup it needs to perform.
One additional thing to be cautious of is that queues can only handle one data type. Because of that, you may also want to consider a Queued Message Handler design pattern. This design pattern allows you to send both a command and data along with that command. I think that would be ideally situated for you since you could send a "Read Instrument" command along with the data for its settings. You can access this design pattern from within LabVIEW as well. If you have LabVIEW 2012 or LabVIEW 2013, see these instructions. The things I've said above also hold true for the Queued Message Handler as well.
Let me know if you have any questions or if this is helpful.
Regards,
Matthew B.
Applications Engineer
National Instruments

Navigation control and event handling in jsf rc1

afternoon folk,
i am using the rc1 release of jsf, and am sorting down through some things. i have a question on the proper way to do the following:
i have a page that gathers some user parameters to be used to submit in generating a report. this report will take around 15 minutes to complete. once i submit the parameters from this page, i have a managed bean stored in session scope that will issue a Thread.run() to run the report as a thread, and allow the page to return without timing out. when the report is complete, it sets a flag in the managed bean i can use to determine that the report is complete. from the user's standpoint, i have a page with the refresh attribute set, that uses the jstl conditional operators to check if the report thread is complete or not. this all works fine. what happens though, is that when the report thread is complete and the page that checks the flag indicating this runs, i haven't found a good way to call the page that i have that will display the results of the operation. my 'monitor' page has the following code snippet in it:
     <c:if test="${MyReport.reportThread.reportRunning}">
     <h:outputText id = "spl" value="#{bundle.stillProcessingLabel}" />
     </c:if>
<c:if test="${MyReport.reportThread.reportRunning == false}">
     <h:commandLink id="done" action="displayResults">
     <h:outputText id = "vrl" value="#{bundle.viewReportsLabel}" />
          </h:outputLink>
     </c:if>
in my faces-config.xml file, i have a navigation rule that says to go to the results page on a value of displayResults coming from the monitor page.
<navigation-rule >
<from-view-id>/monitor.jsp</from-view-id>
<navigation-case>
<description>
Holding page for the user till the reports are completed
</description>
<from-outcome>displayResults</from-outcome>
<to-view-id>/displayResults.jsp</to-view-id>
</navigation-case>
</navigation-rule>
what happens is that the stillProcessingLabel message displays for each refresh cycle of the page (that is set using the <meta http-equiv="refresh" content="60"> until the report thread is complete, but once that occurs, i do not see the command link output, and the page that called this monitor page is displayed without any user interaction, not the results page.
any suggestions as to how to handle this, and why it is occurring would be appreciated.
thanks
tom

I had a similar issue in a project I am working on. I'm not sure if I did this the "Best Practices" way or not, but it works perfectly.
In the head area of my JSP I include the following:
<f:view>
    <h:outputText id="refresher1" rendered="#{queryHandler.queryRunning}">
        <f:verbatim escape="false">
            <meta http-equiv="refresh"
                  content="5,<%=response.encodeURL(request.getContextPath()+
                          "/queryStatus.jsf")%>">
        </f:verbatim>
    </h:outputText>
    <h:outputText id="refresher1" rendered="#{queryHandler.queryFinishedRunning}">
        <f:verbatim escape="false">
            <meta http-equiv="refresh"
                  content="5,<%=response.encodeURL(request.getContextPath()+
                          "/queryResults.jsf")%>">
        </f:verbatim>
    </h:outputText>This puts a 5 second refresh meta in the header to direct the browser to the correct page based on the status of the query thread.
There are many ways to accomplish the effect you want. I suggest putting all the controls into the JSP and making use of the rendered attributes instead of the JSTL conditionals to show the controls you want for the state of the application.
-jeffhoward

Event handling with multiple panels

Hi there,
Like many here, I'm very new to this stuff so please bear with me..
I've been building a gui, using a main "parent" JPanel and several
subpanels. The main reason for creating subpanels was to help me
with the layout (someone might let me know if this was a bad idea!).
Now, all of the subpanels generate events in one form or another. What I'd
like to do is find out the best way to handle ALL of the events that
can be generated from my various subpanels from the "parent" panel. Hopefully
this makes sense :) Could anyone offer any suggestions as to the best way
to achieve this?
For example, panel1 is a JPanel contains a slider and a button.
multipanel is another JPanel that contains 6 panel1's. finally
the main (parent) panel contains the multipanel.
So, a program that creates an instance of the parent panel wants to know
the value that one of the sliders on one of the panels in the multipanel
has (!). How does it get the value?
I hope I explained myself! Many thanks in advance for any advice offered,
dan

class InnerPanel extends JPanel {
Vector listeners;
public void add(SwingEventListener lsnr) {
listeners.add(lsnr);
protected void notifyListeners(AWTEvent ev) {
for (Iterator i = listeners.iterator();i.hasNext();) {
SwingEventListener lsnr = (SwingEventListener) i.next();
lsnr.eventPeformed(ev);
public void actionPerformed(ActionEvent ev) {
notifyListener(ev);
Your SwingEventListener will be
interface SwingEventListener {
public void eventPefromed(AWTEvent event);
public ParentPanel extends JPanel implements SwingEventListener {
public void eventPerformed(AWTEvent event) {
... do what is required.

Event handling with buttons and mouse

Hi, Im a beginner in Java...!!!
I have 4 buttons with me- 2 for color(red,blue) and 2 for size(big,small)..
How do we divide the frame into 2 panels..one for Buttons and Other for Mouse events...
Now,if I click on RED button and BIG button..and later click in the Mouse Panel area..I shud get a big rectangle filled with red color..and similarly for small / blue..etc...if a new selection is made..the previous rectangles should remain as they are...
Im unable to get the implementation...any help will be appreciated.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class ButtonPanel extends JPanel
implements ActionListener, MouseMotionListener
{ public ButtonPanel()
blueButton = new JButton("Blue");
redButton = new JButton("Red");
bigButton = new JButton("Big");
smallButton = new JButton("small");
add(blueButton);
add(redButton);
add(bigButton);
add(smallButton);
blueButton.addActionListener(this);
redButton.addActionListener(this);
bigButton.addActionListener(this);
smallButton.addActionListener(this);
public void actionPerformed(ActionEvent evt)
Color color = getBackground();
repaint();
// Paint Method
public void paintComponent(Graphics g)
{ super.paintComponent(g);
class ButtonFrame extends JFrame
{ public ButtonFrame()
{ setTitle("ButtonTest");
setSize(300, 200);
addWindowListener(new WindowAdapter()
{ public void windowClosing(WindowEvent e)
{ System.exit(0);
Container contentPane = getContentPane();
contentPane.add(new ButtonPanel());
public class ButtonTest
{ public static void main(String[] args)
{ JFrame frame = new ButtonFrame();
frame.show();
}

can U kindly code it for me....!!!you're getting closer,
http://saloon.javaranch.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic&f=2&t=011033but rent-a-coder is that way ---->

Event handling with TextArea

hi all,
i'm really new to java programming !
so, i will be glad for any help that is given by you.
this is the problem:
when we add text in to a TextArea, an event should be
fired. that means, we should capture the status change of the TextArea.
i tried with: implementing Actionlistener
ItemStateChanged
but didn't work !
any suggestions ?
thanx
neo

Try adding a TextListener.

Unobstrusive event handling with Spry

Hi,
I've got this
In one of my javascript files I have the function
function storeCaret(mytext) {
if (mytext.createTextRange) {
mytext.caretPos = document.selection.createRange().duplicate();
In my source I have
<textarea name="ReplyQuote" rows="10" id="ReplyQuote" onselect="storeCaret(this);" onclick="storeCaret(this);" onkeyup="storeCaret(this);" onchange="storeCaret(this);">Text in here</textarea>
Which has various event handlers that I would like to make unobtrusive.
I've tried
Spry.$$('#ReplyQuote').addEventListener("change",storeCaret(this),false);
Spry.$$('#ReplyQuote').addEventListener("click",storeCaret(this),false);
Spry.$$('#ReplyQuote').addEventListener("keyup",storeCaret(this),false);
Spry.$$('#ReplyQuote').addEventListener("select",storeCaret(this),false);
But it's just not returning the correct reference to the function storeCaret. So I guess my understanding of this needs improving. How do I ensure I pass the same reference unobtrusively?
Thanks
Phil

Spry.$$
('#ReplyQuote').addEventListener("change",storeCaret(this),false);
that will execute the storeCaret() function inside the observer.. The
function should be passed in as reference to the function. (without
the () );
Spry.$$('#ReplyQuote').addEventListener("change",storeCaret,false);
Will work. the "this" inside the function will reference to your
ReplyQuote

Event handling with images

I am not sure how to get my images to respond to the mouseClicked event. I need to know how I can get an image to play an audio clip once it is clicked on.

I am not too sure how to do that, so I will show you the code that I am using for my DrawingPanel class. I have a MyApp class as the main. I have the part in the mouselistener commented out because it doesn't compile. Please list a suggestion.
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.event.*;
import java.applet.AudioClip;
import java.net.URL;
import java.net.MalformedURLException;
public class DrawingPanel extends JPanel
private Image goku, trunks, vegeta, gohan, piccolo, background;
private AudioClip clip1, clip2, clip3, clip4, _clip5;
private JApplet _app;
public DrawingPanel(JApplet app)
super();
_goku = new ImageIcon("goku.gif").getImage();
_vegeta = new ImageIcon("vegeta.gif").getImage();
_gohan = new ImageIcon("gohan.gif").getImage();
_trunks = new ImageIcon("trunks.gif").getImage();
_piccolo = new ImageIcon("piccolo.gif").getImage();
_background = new ImageIcon("DBZ%20wallpaper%202.jpg").getImage();
_clip1 = app.getAudioClip(app.getCodeBase(), "goku.wav");
_clip2 = app.getAudioClip(app.getCodeBase(), "vegeta.wav");
_clip3 = app.getAudioClip(app.getCodeBase(), "gohan.wav");
_clip4 = app.getAudioClip(app.getCodeBase(), "trunks.wav");
_clip5 = app.getAudioClip(app.getCodeBase(), "piccolo.wav");
_app = app;
public void Play1()
_clip1.play();
public void Play2()
_clip2.play();
public void Play3()
_clip3.play();
public void Play4()
_clip4.play();
public void Play5()
_clip5.play();
public void paint(Graphics g)
super.paint(g);
g.drawImage(_background, 0, 0, app.getWidth(), app.getHeight(), null);
g.drawImage(_goku, 100, 100, 150, 200, null);
g.drawImage(_vegeta, 350, 100, 150, 200, null);
g.drawImage(_gohan, 300, 400, 150, 200, null);
g.drawImage(_trunks, 100, 400, 150, 200, null);
g.drawImage(_piccolo, 550, 100, 150, 200, null);
this.addMouseListener(new MyMouseListener(this));
private class MyMouseListener extends MouseInputAdapter {
private DrawingPanel _dp;
private Point _point;
public MyMouseListener (DrawingPanel dp) {
_dp = dp;
public void mouseClicked (MouseEvent e){
_point = e.getPoint();
/*if (_goku.getPoint() == _point) {
_dp.Play1();
else if (_vegeta.contains(e.getPoint()) == _point) {
_dp.Play2();
else if (_gohan.contains(e.getPoint()) == _point) {
_dp.Play3();
else if (_trunks.contains(e.getPoint()) == _point) {
_dp.Play4();
else if (_piccolo.contains(e.getPoint()) == _point) {
_dp.Play5();
}

Event handling with JSF

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