APEX Training

Sunday, 19 October 2008

Dynamic Charts

Whenever you need to create a chart with multiple series, you will go there and hardcode those series, creating an almost identical SQL for each one of them. As long as your values remain the same, that will be ok. But what if they change? Actualy, the solution is pretty simple - you need to create a PL/SQL Block to return all the series in one SQL. This example in my Demo Application shows how to write such a Function.



If you replace the column and table names, you can use the same function for all of your charts with multiple series.

Enjoy.

Sunday, 5 October 2008

Tabular Form - Checkbox for Setting values to 'Y' or 'N'

This is also one of frequently asked question in the Apex Forum:

http://forums.oracle.com/forums/thread.jspa?threadID=493243

http://forums.oracle.com/forums/thread.jspa?threadID=714172

Using a checkbox for deleting rows is fine, but how do you use it if you want to flag the records and have a value updated depending on the checkbox status (valid/invalid, yes/no)?

It was Patrick Wolf who initially helped me to understand how a checkbox array works. He also created an example (on the fly) to show this can be managed. However, this example was based on a standard tabular form and it couldn't be reporoduced by many interested visitors of my Demo Application. Since this question has been repeated several times in the last couple of weeks, I decided to create a new example, which is based on a manual tabular form.



So, if you have a similar requirement, which is there in many cases, you may want to have a look here:

http://apex.oracle.com/pls/otn/f?p=31517:219

Wednesday, 1 October 2008

Validation with Ajax

As soon as you need to do some date or number validations using javascript, you will notice how cumbersome that attempt could be. Just recently, I had to programm an application which needed some date and number validations prior to the page submittion. I found that using ajax and letting your database do those kind of cheks is a quite elegant way.

In my Demo Application you will find an example

http://apex.oracle.com/pls/otn/f?p=31517:217

showing how easy it is to set it up.

Especially the date validation is funny. It will accept all kinds of date formats:

sep/15.08 03:16:00 AM

sep.15-08 03:16:00 AM

sep/15/08 03

and it will, of course, give you a user friendly message if you go too far and try entering something like this:

14.15-08 03:16:00 AM



or for

10.15-08 13:16:00 AM

you will receive



Try changing your browser language settings from english to any other language and do the excercise again.