QuickTips: MultiSelect LOV and limited number of list members

If your multiselect list refuses to show all the values of your list, then you can go to the page bindings, click on the iterator and change "RangeSize" to a higher value (by default it is 25).

Button actionListener with an actionEvent.queue() issue

The other day, I faced an issue with the programmatic taskflow navigation. At first, it seemed to be a simple task. The purpose was to click a button on a page and navigate to the next step in the bounded taskflow.

The environment is MS Windows 10, JDeveloper is 12.2.1 (Build JDEVADF_MAIN_GENERIC_151011.0031.S).

The code for the button is:
af:button text="button 1" id="b1" action="save" actionListener="#{viewScope.bean.validate}"


The code for the actionListener is:
public void validate(ActionEvent actionEvent) {
        RichButton saveButton = (RichButton) actionEvent.getComponent();
        ActionEvent action = new ActionEvent(saveButton);
        System.out.println("The listener has fired ########### ");
        action.queue();
}

When the button is clicked, the actionListener fires continuously, so the user sees that the application is hang. The Oracle Support has opened a bug 23325363 : TASKFLOW NAVIGATION USING ACTIONLISTENER IS FIRED CONTINUOUSLY, which is being worked on a priority.

Update, which works OK, but the question still remains. "save" is the name of action.

public void validate(ActionEvent actionEvent) {
//RichButton saveButton = (RichButton) actionEvent.getComponent();
//ActionEvent action = new ActionEvent(saveButton);
//action.queue();

NavigationHandler nvHndlr =
FacesContext.getCurrentInstance().getApplication().getNavigationHandler();
nvHndlr.handleNavigation(FacesContext.getCurrentInstance(),
null,"save");
}

Harry Potter and how to create MySQL fields which are auto incremented to use with ADF BC

MySQL has an auto_increment field, which can be used as a primary key. A sequence object when you think in Oracle database terms. But in the case of Oracle you can access to sequence values directly, but in the case of MySQL you don't have such a possibility.
If you want to have a field, which is auto incremented and still have the flexibility you can follow the steps below.

Create a table (counters) which stores a sequence name and last value.

CREATE TABLE `counters` (
  `counter_code` varchar(40) NOT NULL,
  `last_id` bigint(20) unsigned NOT NULL,
  `created_by` varchar(40) DEFAULT NULL,
  `creation_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `last_updated_by` varchar(40) DEFAULT NULL,
  `last_updated_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`counter_code`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

Create a procedure, which increases the sequence value and returns the value as an out parameter.
Note, that the procedure updates the counters table, this means that it has to issue a lock, which maybe the source of a bottleneck.

DELIMITER $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `get_next_sequence_id`(in counterCode varchar(128), out lastId  bigint(20) unsigned)
BEGIN
DECLARE rowCount integer;

DECLARE CONTINUE HANDLER FOR NOT FOUND SET rowCount=0;
DECLARE EXIT HANDLER FOR SQLEXCEPTION ROLLBACK;
DECLARE EXIT HANDLER FOR SQLWARNING ROLLBACK;

SELECT
    COUNT(*)
INTO rowCount FROM
    counters
WHERE
    counter_code = counterCode;

if rowCount=0 then
START TRANSACTION;
INSERT INTO counters
(counter_code,last_id,created_by) VALUES(counterCode,1,'system');
COMMIT;
SET lastId =1;
else
START TRANSACTION;

UPDATE counters
SET
    last_id = (@cur_value:=last_id) + 1,
    last_updated_by = 'system'
WHERE
    counter_code = counterCode;
 
SELECT @cur_value + 1 INTO lastId;
   
   COMMIT;
end if;
END$$
DELIMITER ;

In your ADF Model Entity Object class create the following.

    @Override
    protected void create(AttributeList attributeList) {
        int nextVal = 0;
        super.create(attributeList);
        nextVal = getNextSequenceValue("NEWSEQ");
        setAttribute("ReportId", new BigDecimal(nextVal));
    }

    public int getNextSequenceValue(String sequenceNumber) {
        int nextVal = 0;
        DBTransactionImpl transaction = (DBTransactionImpl) getDBTransaction();
        CallableStatement statement = transaction.createCallableStatement("call get_next_sequence_id(?,?);", 0);
        try {
            statement.setString(1, sequenceNumber);
            statement.registerOutParameter(2, Types.INTEGER);
            statement.execute();
            nextVal = statement.getInt(2);
            statement.close();

        } catch (SQLException e) {
            throw new JboException(e);
        } finally {
            try {
                if (statement != null) {
                    statement.close();
                }
            } catch (SQLException e) {
                throw new JboException(e);
            }
        }
        return nextVal;
    }

Or you can create the same method in your AM and wire it to your attribute default value (choose "Expression") by the help of a groovy expression:adf.object.getDBTransaction().getRootApplicationModule().getNextSequenceValue("NEWSEQ")

Troubleshooting read only selectOneChoice content alignment issue

While using an ALTA UI with JDeveloper 12c (12.2.1) I have noticed the following misbehavior.

As you can see, when selectOneChoice component is set to read only, the label and the content are misaligned.

This can be resolved by surrounding the component with panelLabelAndMessage component (set the label of panelLabelAndMessage to the label selectOneChoice and set simple the attribute of selectOneChoice to true (simple=true). But this approach is much time consuming, so this has to be addressed by skinning the component.

Add new skin into your project, to make troubleshooting easier add

   
        If this parameter is true, there will be an automatic check of the modification date of your JSPs, and saved state will be discarded when JSP's change. It will also automatically check if your skinning css files have changed without you having to restart the server. This makes development easier, but adds overhead. For this reason this parameter should be set to false when your application is deployed.
        org.apache.myfaces.trinidad.CHECK_FILE_MODIFICATION
        true
   
   
        No obfuscation of CSS.
        org.apache.myfaces.trinidad.DISABLE_CONTENT_COMPRESSION
        true
   

into your web.xml file. The description is here http://docs.oracle.com/cd/E21764_01/user.1111/e21420/adfsg_apply.htm#ADFSG312

The second parameter DISABLE_CONTENT_COMPRESSION is essential as if you do not set it, you won't see "human" readable tags while you troubleshoot the issue with FireBug or similar skin inspecting tools.

So when the page is rendered, you inspect the component under the question and you shall see the similar picture.

If you make changes to

.af_selectOneChoice.p_AFReadOnly .AFPanelFormLayoutContentCell {
    padding-left: 12px;
}

and add padding-top: 10px;

This will fix the issue, to make it a permanent fix add the following into your skin file.

af|selectOneChoice:read-only .AFPanelFormLayoutContentCell {
    padding-top: 8px;
}

And here is the result

P.S. Reset back CHECK_FILE_MODIFICATION and DISABLE_CONTENT_COMPRESSION to their default values when you deploy your application to production.