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 the post open and why was
it not just put at the end of the open event? At first I was really confused
by the question. It was like he was asking me why do we have arrays? I just
couldn't imagine not knowing the answer.
Then it occurred to me that I learned the answer to that question from a ... (more)
One of the most useful custom objects that I've ever written is my
master_detail object. It holds a prominent place in my toolkit. This article
will take you through the steps of how to write one and in the process
de-mystify the object.
First we want something that looks like Figure 1. Selecting a row in the top
DataWindow will display the details in the bottom. I'm sure that you've seen
this kind of DataWindow and you've probably written many of them. The key
here is not to tell you how to write this but how to simplify every one that
you will write in the future. For our exam... (more)
This is the third and final part of a series presenting a proposal for the
use of the tag property of DataWindow columns. My original thought was to
provide a means to automatically set a microhelp for each column. Of course,
if you are using an MDI application you have a function to set the microhelp,
but that function is only available in MDI. If you are using any other
application type, then this is not available to you.
Even if you do have an MDI, I have found that the microhelp is not as useful
as I would like. The microhelp is always on the frame, nowhere near the
column. ... (more)
This article describes how to create a grid presentation window that allows
sorting by clicking on the column header.
To begin we need to create a grid DataWindow. I'm selecting just a few
columns from the employee table. Here is my sql for the DataWindow in Figure
Once we have created it I get the DataWindow painter shown in Figure 2.
There are several changes that we need to make. Let's change the status
column so it's no longer a set of radio buttons. This is a read-only screen
so let's remove the status and add a computed field.
To do this let's remove the Status column ... (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)