Event handling pattern

Let me know if this is a good path to take for my event handling framework. I am extending the Observable class with the model and implementing the Observer interface to watch the model
Basic layout
View0/Model0
Model0 extends Observable class
View0 contains addObservable and removeObservable functions which simply add or remove Observer to the model.
View1 wants to listen to View0
View1 implements Observer interface
View1 adds itself as an Observer to View0 which translates to listening to Model0.
The only problem with this is that you extend the Observable class which makes your model unable to extend a base model.
Any thoughts or is there a more elegant solution?
Thanks
Matt

bump

Similar Messages

Queue based UI Event Handler Pattern (CLD)

Hi, everybody:
I am trying to get a better understanding of the Queue based UI Event Handler pattern in CLD exam. So I made the attached small LabVIEW program in which 3 buttons(State 0, State 1, State 2) are the 'switches' of 3 LED lights (S0, S1, S2), respectively. After comparing with the Queue based UI Event Handler pattern in NI's slide, I got some questions at the following points:
(1) There are six items(Initialize, Waiting for Event, State 0, State 1, State 2 and Stop) in the Enum constant in my program. To make this program use standard Queue based UI Event Handler pattern, should I only use 3 cases(Initialize, Waiting for Event, Stop) in the case structure and put 4 events(State 0, State 1, State 2 and Stop) under the case of 'Waiting for Event' ? Is what I coded a standard Queue based UI Event Handler pattern?
(2) In the attached screenshot of Queue based UI Event Handler pattern in NI's slide, I found 'Start' is wired with 'Enqueue Element.vi'. Why is that? Should there be a 'Start' Case in the case structure?
(3) In my program, I wired 'Waiting for Event' with 'Enqueue Element.vi' in all events except 'Stop' event. Should I wire 'State 0', 'State 1', 'State 2' with 'Enqueue Element.vi' in their corresponding events, just like my second question in NI's slide?
BTW, I didn't find the exact Queue based UI Event Handler pattern in LabVIEW 2011, Should we code it by ourselves in the real CLD exam?
Thanks a lot in advance!
Chuan
Attachments:
Queue based UI Event Handler Practice.vi ‏18 KB
NI Slide.png ‏177 KB

Chuan wrote:
Hi, everybody:
I am trying to get a better understanding of the Queue based UI Event Handler pattern in CLD exam. So I made the attached small LabVIEW program in which 3 buttons(State 0, State 1, State 2) are the 'switches' of 3 LED lights (S0, S1, S2), respectively. After comparing with the Queue based UI Event Handler pattern in NI's slide, I got some questions at the following points:
(1) There are six items(Initialize, Waiting for Event, State 0, State 1, State 2 and Stop) in the Enum constant in my program. To make this program use standard Queue based UI Event Handler pattern, should I only use 3 cases(Initialize, Waiting for Event, Stop) in the case structure and put 4 events(State 0, State 1, State 2 and Stop) under the case of 'Waiting for Event' ? Is what I coded a standard Queue based UI Event Handler pattern?
What exactly are you trying to do with this program? Just using it to show a basic pattern for review?
Seems like you are trying to use Queues, a Case Structure, and Events all in one loop. Be careful not to try to be so advanced for this test. I still can't seem to figure out what the question you are trying ask is, but reply and we'll see if we can figure out an answer. You can put as many "states" in an Enum as you want but just not use them all during the program. I use fillers sometimes "just in case" I need to use it. Obviously, don't do this for a real program.
(2) In the attached screenshot of Queue based UI Event Handler pattern in NI's slide, I found 'Start' is wired with 'Enqueue Element.vi'. Why is that? Should there be a 'Start' Case in the case structure?
Your code is your code. This is just an example of the way that you could do it if you wanted to. You need to read the requirements document to determine exactly the way to Initialize and Start and whatever else your program. Typically, I've seen the following included in software using this structure: Initialize, Start, Run, Stop, Update Settings, Exit...and so on.
(3) In my program, I wired 'Waiting for Event' with 'Enqueue Element.vi' in all events except 'Stop' event. Should I wire 'State 0', 'State 1', 'State 2' with 'Enqueue Element.vi' in their corresponding events, just like my second question in NI's slide?
Well, you never ended up using the Initialize case. You need to Initialize outside the loop in your program. Again, try to explain your design more. It seems like what you have done is right, but I'm not sure what all you are trying to accomplish.
BTW, I didn't find the exact Queue based UI Event Handler pattern in LabVIEW 2011, Should we code it by ourselves in the real CLD exam?
All code on the CLD needs to be your own. Templates are just there as a starter for people who are not familiar with them. If you want to take the CLD, you should be at the point where you don't need the templates to do the work for you.
Thanks a lot in advance!
Chuan
See my responses above. Best of luck.
The pattern you have used in your program is *technically* fine, but in all the code I wrote for the CLD and in most of the examples I saw, everything was just a state machine with a enum driver. Be careful trying to violate the norm on this as you will likely run into more problems than solutions. You could also encapsulate your Queue into an FGV, which would modularize the code and look a little neater.
Nathan - Certified LabVIEW Developer

Event handler switch creation (for repeated use )

Im creating a hyperterminal like application which reads from serial port and writes into serial port.
The reading and writing works almost fine..I also wants to create some custom "Key controls" that will send some prestored commands to the serial port.
I currently implemented two commands "ESC" and "FLASH " in the Key controls menu..
I want to send these commands ESC and FLASH each time i click a button in the menu.
I used event handler for it..and put the event handler inside an always running while loop.
But the problem is I can send only these commands only for one time during execution.
Repeated pressing of switches doesnt cause any effects..
Can somebody help please???
Im using labview 6.1. If u modify VIs using higher versions i cant open here..kindly include a jpg screenshot inthat case.
Thanking you.
Stephen.
Attachments:
Serial Port(stable release)1.2.vi ‏113 KB
Init.vi ‏32 KB
Write.vi ‏44 KB

Hi Stephen,
in LV7.1 your events will be executed whenever I press one of the according switches...
Notes:
-Don't make several event structures. Instead make one event structure with several event cases. Read the context help for the event structure!
-I would suggest to set the mechanical action of both switches to "latch when pressed" instead of "switch..." to give a feedback to the user as the switch will be reset after reading it...
-Generally be more styleguide-conform! Use right-click on terminals to create controls/constants to avoid coercion dots (spot the red colored dots in the image?). Make error in/out in the lower left/right of the connector pattern. Avoid block diagrams larger than the screen (or what kind of monitor do you use?).
Edited:
Sorry for weird display. I have to get used to the new image gallery feature of the forum (and will use "image to the left" only on rare conditions). Btw. the preview looks different to the actual post
Message Edited by GerdW on 05-28-2009 06:59 AM
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

General Event Handling (Outside AWT)

Hi all, I am looking for info on allowing my classes to send and recieve events between classes (the set of events is to be defined by me). What is Java's event handling approach? Is there something outside the AWT?
I realise there may be design patterns for this scenario but though there may be some Java specific way as well (like in the AWT).
Thanks,
David

listeners.
like this...
FooEvent <- your event class
FooEventListener <- listener interface
FooMaker <- class that generates foo events
An interface for the listener.
public interface FooEventListener{
public void processEvent(FooEvent evt);
}the class making the events
public FooMaker{
// among other things might have methods like...
public void addFooEventListener(FooEventListener fel){
// add the listener to some collection
// called when events happen
private void notifyListeners(){
// notify each listener
}and your listeners will implement the interface.
does that help?

How can I execute an external program from within a button's event handler?

I am using Tomcat ApacheTomcat 6.0.16 with Netbeans 6.1 (with the latest JDK/J2EE)
I need to execute external programs from an event handler for a button on a JSF page (the program is compiled, and extremely fast compared both to plain java and especially stored procedures written in SQL).
I tried what I'd do in a standalone program (as shown in the appended code), but it didn't work. Instead I received text saying the program couldn't be found. This error message comes even if I try the Windows command "dir". I thought with 'dir' I'd at least get the contents of the current working directory. :-(
I can probably get by with cgi on Apache's httpd server (or, I understand tomcat supports cgi, but I have yet to get that to work either), but whatever I do I need to be able to do it from within the button's event handler. And if I resort to cgi, I must be able to maintain session jumping from one server to the other and back.
So, then, how can I do this?
Thanks
Ted
NB: The programs that I need to run do NOT take input from the user. Rather, my code in the web application processes user selections from selection controls, and a couple field controls, sanitizes the inoputs and places clean, safe data in a MySQL database, and then the external program I need to run gets safe data from the database, does some heavy duty number crunching, and puts the output data into the database. They are well insulated from mischeif.
NB: In the following array_function_test.pl was placed in the same folder as the web application's jsp pages, (and I'd tried WEB-INF - with the same result), and I DID see the file in the application's war file.
        try {
            java.lang.ProcessBuilder pn = new java.lang.ProcessBuilder("array_function_test.pl");
            //pn.directory(new java.io.File("K:\\work"));
            java.lang.Process pr = pn.start();
            java.io.BufferedInputStream bis = (java.io.BufferedInputStream)pr.getInputStream();
            String tmp = new String("");
            byte b[] = new byte[1000];
            int i = 0;
            while (i != -1) {
                bis.read(b);
                tmp += new String(b);
            getSelectionsDisplayTextArea().setText(getSelectionsDisplayTextArea().getText() + "\n\n" + tmp);
        } catch (java.io.IOException ex) {
            getSelectionsDisplayTextArea().setText(getSelectionsDisplayTextArea().getText() + "\n\n" + ex.getMessage());
        }

Hi Fonsi!
One way to execute an external program is to use the System Exec.vi. You find it in the functions pallet under Communication.
/Thomas

Copying text to the clipboard in AVDocDidOpen event handler causes Acrobat 9 to crash

I'm trying to copy the filename of a document to the clipboard in a plugin with my AVDocDidOpen event handler. It works for the first file opened; however when a second file is opened, Acrobat crashes. The description in the application event log is: "Faulting application acrobat.exe, version 9.1.0.163, faulting module gdi32.dll, version 5.1.2600.5698, fault address 0x000074cc."
I've confirmed that the specific WIN32 function that causes this to happen is SetClipboardData(CF_TEXT, hText); When that line is commented out and remaining code is left unchanged, Adobe doesn't crash.
Is there an SDK function that I should be using instead of WIN32's SetClipboardData()? Alternately, are there other SDK functions that I need to call be before or after I call SetClipboardData()
Bill Erickson

Leonard,
I tried it with both "DURING, HANDLER, END_HANDLER" and "try catch," as shown below. However, it doesn't crash in the event handler; it crashes later, so the HANDLER/catch block is never hit.
The string that's passed to SetClipboardData() is good, because I'm able to paste it into the filename text box of the print dialog when I try to create the "connector line" PDF. I also got rid of all the string manipulation and tried to pass a zero-length string to the clipboard but it still crashes.
Here's the code:
ACCB1 void ACCB2 CFkDisposition::myAVDocDidOpenCallback(AVDoc doc, Int32 error, void *clientData)
    PDDoc pdDoc = AVDocGetPDDoc(doc);
    char* pURL = ASFileGetURL(PDDocGetFile(annotDataRec->thePDDoc));
    if (pURL)    {
        if (strstr(pURL, "file://") && strstr(pURL, "Reviewed.pdf")) {
            // Opened from file system so copy filename to clipboard for connector line report
            char myURL[1000];
            strcpy(myURL, pURL);
            ASfree(pURL);    // Do this before we allocate a Windows handle just in case Windows messes with this pointer
            pURL = NULL;
            HGLOBAL hText = GlobalAlloc(GMEM_MOVEABLE, 1000);
            if (hText)    {
                try
                    // Skip path info and go right to filename
                    char *pText = (char *)GlobalLock(hText);
                    char *pWork = strrchr(myURL,'/');
                    if (pWork)    {
                        strcpy(pText, pWork+1);
                    } else {
                        strcpy(pText, myURL);
                    char *pEnd = pText + strlen(pText);    // Get null terminator address
                    // Replace "%20" in filename with " "
                    pWork = strstr(pText, "%20");
                    while (pWork)    {
                        *pWork = ' ';
                        memmove(pWork+1, pWork+3, (pEnd - (pWork+2)));
                        pWork = strstr(pText, "%20");
                    // Append a new file extension
                    pWork = strstr(pText, ".pdf");
                    *pWork = 0;    // truncate the string before ".pdf"
                    strcat(pWork,".Connectors.pdf");
                    GlobalUnlock(hText);     // Must do this BEFORE SetClipboardData()
                    // Write it to the clipboard
                    OpenClipboard(NULL);
                    EmptyClipboard();
                    SetClipboardData(CF_TEXT, hText);     // Here's the culprit
                    CloseClipboard();
                    GlobalFree(hText);
                } catch (char * str) {
                    AVAlertNote(str);
        if (pURL)
            ASfree(pURL);

Unable to get automatic event handling for OK button.

Hello,
I have created a form using creatobject. This form contains an edit control and Search, Cancel buttons. I have set the Search buttons UID to "1" so it can handle the Enter key hit event. Instead its caption changes to Update when i start typing in the edit control and it does not respond to the Enter key hit. Cancel happens when Esc is hit.
My code looks like this -
Dim oCreationParams As SAPbouiCOM.FormCreationParams
        oCreationParams = SBO_Application.CreateObject(SAPbouiCOM.BoCreatableObjectType.cot_FormCreationParams)
        oCreationParams.UniqueID = "MySearchForm"
        oCreationParams.BorderStyle = SAPbouiCOM.BoFormBorderStyle.fbs_Sizable
                Dim oForm As SAPbouiCOM.Form = SBO_Application.Forms.AddEx(oCreationParams)
oForm.Visible = True
'// set the form properties
        oForm.Title = "Search Form"
        oForm.Left = 300
        oForm.ClientWidth = 500
        oForm.Top = 100
        oForm.ClientHeight = 240
        '// Adding Items to the form
        '// and setting their properties
        '// Adding an Ok button
        '// We get automatic event handling for
        '// the Ok and Cancel Buttons by setting
        '// their UIDs to 1 and 2 respectively
        oItem = oForm.Items.Add("1", SAPbouiCOM.BoFormItemTypes.it_BUTTON)
        oItem.Left = 5
        oItem.Width = 65
        oItem.Top = oForm.ClientHeight - 30
        oItem.Height = 19
        oButton = oItem.Specific
        oButton.Caption = "Search"
        '// Adding a Cancel button
        oItem = oForm.Items.Add("2", SAPbouiCOM.BoFormItemTypes.it_BUTTON)
        oItem.Left = 75
        oItem.Width = 65
        oItem.Top = oForm.ClientHeight - 30
        oItem.Height = 19
        oButton = oItem.Specific
        oButton.Caption = "Cancel"
oItem = oForm.Items.Add("NUM", SAPbouiCOM.BoFormItemTypes.it_EDIT)
        oItem.Left = 105
        oItem.Width = 140
        oItem.Top = 20
        oItem.Height = 16
        Dim oEditText As SAPbouiCOM.EditText = oItem.Specific
What changes do i have to make to get the enter key to work?
Thanks for your help.
Regards,
Sheetal

Hello Felipe,
Thanks for pointing me to the correct direction.
So on refering to the documentation i tried out a few things. But I am still missing something here.
I made the following changes to my code -
oForm.AutoManaged = True
oForm.SupportedModes = 1 ' afm_Ok
oItem = oForm.Items.Add("1", SAPbouiCOM.BoFormItemTypes.it_BUTTON)
        oItem.Left = 5
        oItem.Width = 65
        oItem.Top = oForm.ClientHeight - 30
        oItem.Height = 19
oItem.SetAutoManagedAttribute(SAPbouiCOM.BoAutoManagedAttr.ama_Visible, 1, SAPbouiCOM.BoModeVisualBehavior.mvb_Default)
        oButton = oItem.Specific
        oButton.Caption = "OK"
AND
oForm.Mode = SAPbouiCOM.BoFormMode.fm_OK_MODE
oItem = oForm.Items.Add("1", SAPbouiCOM.BoFormItemTypes.it_BUTTON)
        oItem.Left = 5
        oItem.Width = 65
        oItem.Top = oForm.ClientHeight - 30
        oItem.Height = 19
oItem.AffectsFormMode = False
I get the same behaviour OK button changes to update and enter key does not work.
Could you please tell me find what is it that i am doing wrong?
Regards,
Sheetal

Dropdown box - which event handler to use ?

I am having trouble with setting the readonly property (via Javascript) of the adjacent textbox to my dropdown box when the index value is a certain number.
I tried using MouseUp, MouseDown, and even OnBlur....but the readonly does not seem to be getting set to true or false consistently.
Could this be a timing issue ? The textbox that I am trying to control is the next tab-order control in the list of controls for this page.
This same logic is working fine in the MouseUp event handler for check boxes. So I am just wondering if this is a bug or must my implementation change to accomodate dropdown boxes ? For instance, should I move the logic to the Enter event handler of the textbox instead ? Can a control's own eventhandler set itself to readonly when it is the active form field ?

After tons and tons of testing time, I've come to the conclusion that dropdowns are totally buggy in 11.0.07 release of Acrobat Pro.
Even if you set the "commit values immediately", you get the PRIOR selected item's value as the event value, not the CURRENT one.
This occurs in a Validate event handler script. I have not been able to use any other event handlers for a dropdown except the OnBlur....and then, for my purposes, IT'S TOO LATE !!!
This is totally worthless as I need to setFocus() and set fields to readonly based on the immediate dropdown offset or face value.

Input value given on web page is not getting pickedup in event handler

Hi friends,
I have created one simple page in SE80 with program with flow logic option, in which I would like to show business partner details from BUT000 table with the input of partner number. But the thing is the input value(partner no.)which I am giving on web page is not getting picked up in selection in event handler though I am giving input value it is becoming initial while selecting. What could be the reason?
Below I am mentioning the code which I have written in even handler for OnInputProcessing event.
CASE EVENT_ID.
WHEN 'select'.
NAVIGATION->SET_PARAMETER( 'partner' ).
SELECT * FROM but000 INTO TABLE I_but000 WHERE partner BETWEEN partner AND partner1.
WHEN OTHERS.
ENDCASE.
Thanks in advance,
Steve

Hi Abhinav,
I tried with the one you posted. But it is giving run time error as shown below.
Note
The following error text was processed in the system CRD : Access via 'NULL' object reference not possible.
The error occurred on the application server crmdev_CRD_00 and in the work process 0 .
The termination type was: RABAX_STATE
The ABAP call stack was:
Method: ONINPUTPROCESSING of program CLO24DDFJW575HVAQVJ89KWHEHC9OCP
Method: %_ONINPUTPROCESSING of program CL_O24DDFJW575HVAQVJ89KWHEHC9OCP
Method: DO_REQUEST of program CL_BSP_PAGE===================CP
Method: ON_REQUEST of program CL_BSP_RUNTIME================CP
Method: IF_HTTP_EXTENSION~HANDLE_REQUEST of program CL_HTTP_EXT_BSP===============CP
Method: EXECUTE_REQUEST_FROM_MEMORY of program CL_HTTP_SERVER================CP
Function: HTTP_DISPATCH_REQUEST of program SAPLHTTP_RUNTIME
Module: %_HTTP_START of program SAPMHTTP
Regards,
Steve

How do I create an Event Handler for an Execute SQL Task in SSIS if its result set is empty

So the precedence on my entire package executing is based on my first SELECT of my Table and an updatable column. If that SELECT results in an empty result set, how do I create an Event Handler to handle an empty result set?
A Newbie to SSIS.
I appreciate your review and am hopeful for a reply.
PSULionRP

Depends upon what you want to do in the eventhandler. this is what you can do
Store the result set from the Select to a user variable.
Pass this user variable to a Script task.
In the Script task do whatever you want to do including failing the package this can be done by failing the script task, which in turns fails the package. something like
Dts.TaskResult = Dts.Results.Failure
Abhinav http://bishtabhinav.wordpress.com/

Swing: when trying to get the values from a JTable inside an event handler

Hi,
I am trying to write a graphical interface to compute the Gauss Elimination procedure for solving linear systems. The class for computing the output of a linear system already works fine on console mode, but I am fighting a little bit to make it work with Swing.
I put two buttons (plus labels) and a JTextField . The buttons have the following role:
One of them gets the value from the JTextField and it will be used to the system dimension. The other should compute the solution. I also added a JTable so that the user can type the values in the screen.
So whenever the user hits the button Dimensiona the program should retrieve the values from the table cells and pass them to a 2D Array. However, the program throws a NullPointerException when I try to
do it. I have put the code for copying this Matrix inside a method and I call it from the inner class event handler.
I would thank you very much for the help.
Daniel V. Gomes
here goes the code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import AdvanceMath.*;
public class MathF2 extends JFrame {
private JTextField ArrayOfFields[];
private JTextField DimOfSis;
private JButton Calcular;
private JButton Ativar;
private JLabel label1;
private JLabel label2;
private Container container;
private int value;
private JTable DataTable;
private double[][] A;
private double[] B;
private boolean dimensionado = false;
private boolean podecalc = false;
public MathF2 (){
super("Math Calcs");
Container container = getContentPane();
container.setLayout( new FlowLayout(FlowLayout.CENTER) );
Calcular = new JButton("Resolver");
Calcular.setEnabled(false);
Ativar = new JButton("Dimensionar");
label1 = new JLabel("Clique no bot�o para resolver o sistema.");
label2 = new JLabel("Qual a ordem do sistema?");
DimOfSis = new JTextField(4);
DimOfSis.setText("0");
JTable DataTable = new JTable(10,10);
container.add(label2);
container.add(DimOfSis);
container.add(Ativar);
container.add(label1);
container.add(Calcular);
container.add(DataTable);
for ( int i = 0; i < 10 ; i ++ ){
for ( int j = 0 ; j < 10 ; j++) {
DataTable.setValueAt("0",i,j);
myHandler handler = new myHandler();
Calcular.addActionListener(handler);
Ativar.addActionListener(handler);
setSize( 500 , 500 );
setVisible( true );
public static void main ( String args[] ){
MathF2 application = new MathF2();
application.addWindowListener(
new WindowAdapter(){
public void windowClosing (WindowEvent event)
System.exit( 0 );
private class myHandler implements ActionListener {
public void actionPerformed ( ActionEvent event ){
if ( event.getSource()== Calcular ) {
if ( event.getSource()== Ativar ) {
//dimensiona a Matriz A
if (dimensionado == false) {
if (DimOfSis.getText()=="0") {
value = 2;
} else {
value = Integer.parseInt(DimOfSis.getText());
dimensionado = true;
Ativar.setEnabled(false);
System.out.println(value);
} else {
Ativar.setEnabled(false);
Calcular.setEnabled(true);
podecalc = true;
try {
InitValores( DataTable, value );
} catch (Exception e) {
System.out.println("Erro ao criar matriz" + e );
private class myHandler2 implements ItemListener {
public void itemStateChanged( ItemEvent event ){
private void InitValores( JTable table, int n ) {
A = new double[n][n];
B = new double[n];
javax.swing.table.TableModel model = table.getModel();
for ( int i = 0 ; i < n ; i++ ){
for (int j = 0 ; j < n ; j++ ){
Object temp1 = model.getValueAt(i,j);
String temp2 = String.valueOf(temp1);
A[i][j] = Double.parseDouble(temp2);

What I did is set up a :
// This code will setup a listener for the table to handle a selection
players.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
ListSelectionModel rowSM = players.getSelectionModel();
rowSM.addListSelectionListener(new Delete_Player_row_Selection(this));
//Class will take the event and call a method inside the Delete_Player object.
class Delete_Player_row_Selection
implements javax.swing.event.ListSelectionListener
Delete_Player adaptee;
Delete_Player_row_Selection (Delete_Player temp)
adaptee = temp;
public void valueChanged (ListSelectionEvent listSelectionEvent)
adaptee.row_Selection(listSelectionEvent);
in the row_Selection function
if(ex.getValueIsAdjusting()) //To remove double selection
return;
ListSelectionModel lsm = (ListSelectionModel) ex.getSource();
if(lsm.isSelectionEmpty())
System.out.println("EMtpy");
else
int selected_row = lsm.getMinSelectionIndex();
ResultSetTableModel model = (ResultSetTableModel) players.getModel();
String name = (String) model.getValueAt(selected_row, 1);
Integer id = (Integer) model.getValueAt(selected_row, 3);
This is how I got info out of a table when the user selected it

Problem with event handling

Hello all,
I have a problem with event handling. I have two buttons in my GUI application with the same name.They are instance variables of two different objects of the same class and are put together in the one GUI.And their actionlisteners are registered with the same GUI. How can I differentiate between these two buttons?
To be more eloborate here is a basic definition of my classes
class SystemPanel{
         SystemPanel(FTP ftp){ app = ftp};
         FTP app;
         private JButton b = new JButton("ChgDir");
        b.addActionListener(app);
class FTP extends JFrame implements ActionListener{
           SystemPanel rem = new SystemPanel(this);
           SystemPanel loc = new SystemPanel(this);
           FTP(){
                   add(rem);
                   add(loc);
                   pack();
                   show();
       void actionPerformed(ActionEvent evt){
        /*HOW WILL I BE ABLE TO KNOW WHICH BUTTON WAS PRESSED AS THEY
           BOTH HAVE SAME ID AND getSouce() ?
           In this case..it if was from rem or loc ?
} It would be really helpful if anyone could help me in this regard..
Thanks
Hari Vigensh

Hi levi,
Thankx..
I solved the problem ..using same concept but in a different way..
One thing i wanted to make clear is that the two buttons are in the SAME CLASS and i am forming 2 different objects of the SAME class and then putting them in a GUI.THERE IS NO b and C. there is just two instances of b which belong to the SAME CLASS..
So the code
private JButton b = new JButton("ChgDir");
b.setActionCommand ("1");
wont work as both the instances would have the label "ChgDir" and have setActionCommand set to 1!!!!
Actually I have an array of buttons..So I solved the prob by writting a function caled setActionCmdRemote that would just set the action commands of one object of the class differently ..here is the code
public void setActionCommandsRemote()
     for(int i = 0 ; i <cmdButtons.length ; i++)
     cmdButtons.setActionCommand((cmdButtons[i].getText())+"Rem");
This just adds "rem" to the existing Actioncommand and i check it as folows in my actionperformed method
     if(button.getActionCommand().equals("DeleteRem") )
                    deleteFileRemote();
      else if(button.getActionCommand().equals("Delete") )
                 deleteFileLocal();Anyway thanx a milion for your help..this was my first posting and I was glad to get a prompt reply!!!

Enhance standard class with event handler method

In trying to enhance a standard class with a new event handler class, I find that the ECC 6.0 EHP4 system does not appear to recognise the fact the method is an event handler method. The specific example is a new method to handle the event CL_GUI_ALV_GRID->USER_COMMAND.
I notice that the flag called Active has not been ticked - see image below. Perhaps this is the reason why the event handler is not being triggered.
Note that there is an event handler for the same event in the standard class which obviously is executed as expected. Any ideas on limitations in the system or I am missing a step?
Thanks
John

Thank you for your replies.
There is a bug in the ALV handler of a standard SAP class (when executed in ITS WebGUI) and I was hoping to create a custom event handler as an Enhancement to execute some custom code to sort of "handle the bug".
I agree - ideally it should be done in a Z class but that will not give me access to the object methods and attributes of the enhanced class.
Cheers,
John

Javascript embedded in button pl/sql event handler not being executed

Javascript calls not working from pl/sql button event handler. What am I missing? Are specific settings needed to execute javascript from pl/sql proceedures?
Example: Want to toggle target='_blank' off and on in a button pl/sql event handler to open url call in new window & then reset when processing submit is done & the app returns to the form.
portal form button's pl/sql submit handler:
begin
htp.p('<script language=JavaScript>') ;
htp.p('this.form.target="_blank"') ;
htp.p('</script>') ;
PORTAL.wwa_app_module.set_target('http://www.oracle.com') ;
htp.p('<script language=JavaScript>') ;
htp.p('this.form.target="_blank"') ;
htp.p('</script>') ;
end ;
Putting the following in the button's javascript on_click event handler works great:
this.form.target='_blank'
to force opening new window with a call in the button's submit pl/sql code via:
PORTAL.wwa_app_module.set_target('http://www.oracle.com') ;
but then the target='_blank' is left on when the submit is done & we return to the form.
putting the above javascript as a function (called fcn_newpage) elsewhere (e.g., after form opens) & calling in the submit pl/sql with
htp.p('fcn_newpage') ;
also doesn't work.
Metalink thought this was an application issue instead of a bug, so thought I'd see if anyone knows what's going wrong here. (Portal 9.0.4.1)

thanks for your discussion of my post.
Please clarify:
"htp.p('fcn_newwindow') sends a string":
What would you suggest the proper syntax for a function fcn_newwindow() call from a pl/sql javascript block that differs from
htp.p('<script language="Javascript">') ;
htp.p('fcn_newwindow');
htp.p('</script>');
or more simply
htp.p('fcn_newwindow') ;
More generally, what I'm trying to figure out is under what conditions javascript is executed, if ever, in the pl/sql of a button (either the submit or custom event handler, depending on the button).
I've seen lots of posts asking how to do a simple htp.p('alert("THIS IS TROUBLE")') ; in a pl/sql event handler for a button on a form, but no description of how this can be done successfully.
In addition to alerts, in my case, I'd like to call a javascript fcn from a pl/sql event handle that would pass a URL (e.g., http://www.oracle.com) where the javascript fcn executed
window.open(URL). The API call to set_target(URL) in pl/sql has no ability to open in a new window, so calling that is inadequate to my needs and I must resort to javascript.
Its clear in the PL/SQL of a button, you can effect form components since p_session..set_target & p_session.get_target set or get the contents of form components.
So to see if javascript ever works, I tried to focus on something simple that only had to set what amounts to an enviromental variable when we returned to the form after a post. I chose to try to change the html value of TARGET from javascript in the PL/SQL button because it doesn't need to be implemented until we finish the post and return to the form.
So I focused on a hack, setting this.form.TARGET='_blank' in the on_click event handler that forced every subsequent URL call or refresh of the form to be a new window. I then wanted to turn off opening new windows once I'd opened the URL call in a new window by setting TARGET='' in the portal form. I can achieve what I want by coding this.form.TARGET='' in the javascript (on_focus, on_change, or on_mousedown, ...) of every form component that might refresh the form. However, that is a ridiculous hack when a simple htp.p('<script>') ; htp.p('this.form.target=""') ; htp.p('</script>') ; at the end of the button's pl/sql event handle should do the same thing reliably if javascript ever works in the pl/sql event handler.
If we didn't have access to form components through p_session calls, I'd assume it was a scope issue (what is available from the pl/sql event handler). But unless my syntax is just off, when, if ever, can javascript be used in a portal form's pl/sql event handler for a button?
if I code a javascript funtion in the forms' pl/sql before displaying form:
htp.p('<script language="JavaScript">') ;
htp.p('function fcn_new_window(URL)') ;
htp.p('window.open(URL)' ) ;
htp.p('</script>') ;
the function can be called from a button's on_click javascript event handler:
fcn_new_window('http://www.oracle.com')
but from the same button's pl/sql submit event handler this call doesn't work: htp.p('fcn_new_window("http://www.oracle.com")')
So my questions remain: Is there other syntax I need, or does javascript ever work properly from the pl/sql of a form button's event handler? If it doesn't work, isn't this a bug that should be fixed by Oracle?
I can probably figure out hacks to make things work the way I need, but executing javascript from pl/sql event handlers seems to be the expected way to affect portal html pages (forms, reports, ...) and it seems not to work as expected. I don't feel I should have to implement hacks for something as simple as calling a javascript function from pl/sql when almost every example I've found in metalink or the forums or Oracle Press's "portal bible" suggests using javascript from pl/sql via the utility htp.p() to effect web page components in portal.
My TAR on the subject, while still open, returned the result basically: "We can reproduce your situation. Everything looks okay to us, but we can't explain how to use javascript where you want or point you to any documentation that would solve your problem or expain why it should not work the way you want it to. We don't feel its a technical issue. Why don't you post the problem on the portal applications forum."
I'm hoping I'm just missing something fundamental and everything will work if I implement it a little differently. So if anyone sees my error, please let me know.
by the way, not sure this is germain, but in reference to your comment:
"redirections in pl/sql procedures give a peculiar result. in a pl/sql procedure, usually, portals give the last redirection statement and ignore anything else coming after it."
if I try to raise an alert:
htp.p('alert("you screwed up")');
return;
in a pl/sql event handler, it still doesn't raise the alert, even though its the last thing implemented in the event handler. But if I set the value of a text box using p_session..set_value_as_string() at the same spot, it correctly sets the text box value when I return to the form.

How to create Event Handler in OIM11g

Hi all,
How can I create an event handler in OIM11g
Thank You in advance.

there are three component required to generate this
1. plugin.xml
2. EventHandler class
3. eventhandler.xml to import into MDS schema which define OPERATION,ORDER..etc
you have to zip the first two and register using register utility in <IDM_HOME>server/bin and then import 3rd one into MDS using WeblogicImportMetaData.sh
for details follow below link
http://docs.oracle.com/cd/E14571_01/doc.1111/e14309/oper.htm
Step by step explanation from development to deployement
http://idmoim.blogspot.in/2011/07/developing-and-deploying-oim-11g-custom_29.html
--nayan
Edited by: Nishith Nayan on Feb 8, 2012 8:54 AM

Event handling pattern

Similar Messages

Maybe you are looking for