Every programmer knows about the IF command. It's pretty much a fundamental
part of the syntax of every computer language that has ever existed. I don't
need to explain how it works.
The DataWindow can't use the IF command though. It does, however, support an
IF(expression, TRUE, FALSE)
In its simplest form this means that if the expression evaluates to TRUE,
then whatever statement you supply for the TRUE part is executed. If not then
the FALSE part is.
Let's begin with a simple example. Let's create a DataWindow that will show
employee information. Here is the SQL for it:
Normally I try to write applications on the DataWindow or Appeon but every
now and then I get a question that makes me sit back and say, "Huh?"
In this case the question concerns the PostOpen event. I've seen that event
named different things: ue_post_open, postOpen, post_open, ue_postOpen, etc.
It has, as far as I can see, always had post and open in the name of the
event. Further, just about every framework that I've ever seen has had that
event in the base window.
The question that I was asked was, "Why is that event there?"
The programmer wanted to know why there was code in t... (more)
This article provides a means of automating the sorting of DataWindows... not
just grid DataWindows as discussed in last month's article, but all
DataWindows, regardless of display format.
Bear in mind that we are writing programmer tools. When writing for
programmers we want to give the programmer the maximum number of options
while minimizing the programmer effort. In other words, default as much as
possible but allow the programmer to move beyond the defaults.
We have several action items to implement:
Do the housekeeping to get an application going Create a window for sorting.... (more)
The following article is an excerpt from Rik's upcoming book, ‘Mobile
Application Development using PowerBuilder and Appeon'
I am here to tell you it's true. You can write iPad applications in
PowerBuilder. I'm sure that you are waiting for the other shoe to drop but
ladies and gentlemen, there is no other shoe. It is simply the truth. You can
write iPad applications in PowerBuilder.
Those of you who have iPads, have you ever seen an MDI application running on
an iPad? No? Neither had I. That is until I took a PowerBuilder application
and, using Appeon, deployed to my iPad and ra... (more)
We are going to create a bare-bones email object. Of course you can expand
that in the future if you like, but for now, let's just create the
functionality that we need.
I start by creating a custom class. In case you aren't familiar with the
process look at Figure 1.
Let's start with an instance variable.
N_cst_mailer Instance Variables
private mailMessage io_mail_message // The message to send
I made the instance variables private so let's write a couple of functions to
populate our mail Message. We'll start with the TO. Note that the
io_mail_message contains an array of objec... (more)