Hoyt Nelson

What's the word for a set of objects: DataWindows, DataStores, or DataWindowChilds? If there is a word, I don't know it. Objects don't have any relationship in the PowerBuilder object hierarchy, so that doesn't help.Let's call them DataObjects...oops, that's taken! Lacking any other word, let's stipulate that the term DataWidgets refers to these various DataWindow-ish types. Many native PB functions work for all kinds of DataWidgets. SetItem() applies to DataWindows, DataWindowChilds, and DataStores, for example; so do the GetItemX() functions, such as GetItemString() and GetItemNumber(). It's nice that these functions operate identically for all DataWidget types. If I know how to call SelectRow() for one, I can call it for the others. Which brings up the problem addressed in this article. One of my PowerBuilder pet peeves is the fact that a user-written function c... (more)

Using Overloaded Functions to Determine Object Types

Overloading allows two or more functions to have the same name and return type, if their signature is different. The function signature is defined by its number and types of arguments. When you call an overloaded function, PowerBuilder decides which version of the function to call based on the function signature. This can be exploited to determine an object's type at runtime. This article presents a couple of practical applications of this technique, and describes a third situation where a different technique is required. Technique 1: Validating Arguments I first used this metho... (more)

BBrowse 2.14 by the PowerBuilder Developer's Resource

PowerBuilder provides an object browser - the utility accessed via the "Cubes with a pair of eyeglasses" icon on the PowerBar menu. If you haven't tried the PB browser, you should. Among other things, it eliminates the problem of identifying which PBL contains the object of interest. Click a tab to select an object type and you're immediately presented with a list of the current application's objects of that type. Right-click an object, select Edit from the popup menu and PB opens the object in the relevant painter. It's a fast way to navigate your PB application. The PB browser... (more)

A Pop-Up Debug for Faster, Better Coding

Over the years we've adopted techniques that help us develop our PowerBuilder applications faster and with fewer bugs. This article describes my favorite bag of tricks, the pop-up debug menu (see Figure 1). The debug menu is for developers only and is unavailable when running an executable. Most of the menu items are express aids to development: What is this object and which PBL contains it? Show me the SQL that failed. What is the value of the key column? Replace those SQL question marks with the actual data values. Other items are intended to make it easier to do quality contr... (more)

Popup Debug Menu Part 2

In my previous article (PBDJ, Vol. 8, issue 2), I demonstrated the Object Name feature of the debug popup menu. The popup menu is a developer's tool invoked by holding down a magic key as you right-click a window or control. The initial and most useful debug menu item is Object Name, which you can use to identify any object in your PowerBuilder application as you run the application. Selecting Object Name as you right-click a DataWindow produces output like that shown in Figure 1. Each line in the message box represents a level in the object hierarchy, with the upper item contai... (more)