The DropDownDataWindow (DDDW) edit style is one of PowerBuilder's outstanding
features. Yes, I know there are a lot of new and exciting capabilities in the
upcoming release of PowerBuilder, but in this article I'll try to solve some
of the current problems with the existing features that are popping up in
nearly every project I've seen.
Here I'll focus on DropDownDataWindows, including:
How to get started with DDDWs Filtering DDDWs without losing the display
value in other rows Catching the collapsing of a DDDW Trapping the cursor
keys in a DDDW Autocomplete DDDW values
Getting Started
The basics are well covered in the PowerBuilder User's Manual, but if you
still have problems defining them look at Figure 1. Click on the column you
want and its edit style (yes, click on edit on the properties) as DDDW
(choose DropDownDW as Style Type).
Next, choose your DataWindow, ... (more)
Okay, I know you're already familiar with the PowerBuilder IDE. Yes, you're
one of those people who knows where to find the system tree and how to turn
it off.
And you already know what the clip window is for (if you don't, look at it,
it's a pretty cool feature - we used it in our 7-year-old application to
document who made changes or bug fixes). No, that's not what I'll be talking
about today. I want to discuss the internals of the IDE, as it has improved a
lot since PowerBuilder 7.
The Idea
Why should we take a closer look at the IDE? It works great, we like it, so
everythin... (more)
In Part 1 (PBDJ, Vol. 9, issue 6) I discussed directory services and how they
provide authentication, access control, and finder services for our
application. In Part 2, I explain how the JNDI API lets us easily use LDAP.
JNDI Overview
The Java Naming and Directory Interface (JNDI) is an application programming
interface (API) that provides naming and directory functionality to Java
applications. It's independent of any specific directory service
implementation, thus a variety of directories - new, emerging, and already
deployed - can be accessed the same way.
JNDI Architecture
T... (more)
As architects of enterprise systems, we know that security should always be a
concern when we transfer or store sensitive data. In the past, you might have
cut corners because you assumed the corporate LAN provided some implicit
level of protection. You might have rationalized that because only people
with access to the LAN could see data being transferred across the wire - and
surely no one at your company would try to steal sensitive data - your data
was secure. Likewise, your internal applications might not have been passing
sensitive information and you leveraged password pro... (more)
Many of us started playing around with Java several years ago, fighting our
way through CLASSPATH variables, packages, and javac.exe, and ended up with
our first "Hello World" or file read/write/close application. What did we use
to write our first small application and classes? Notepad or another of our
favorite text editors. Do you know what? We were happy. We didn't need to
learn another IDE and we produced some small Java tools in a reasonable time.
However, Java grew very, very fast. Suddenly there was Swing and EJBs and,
wow, wait, there was a complete specification on how t... (more)