PROGRAMMING - THE BASICS

Forms are the lifeblood of any abcDB™ application.  They allow the user to input and edit data the way that’s most appropriate for the situation.  In this chapter, we’re going to construct three applications. 

1.      First, we’ll create a very simple ‘HELLO WORLD’ application which will demonstrate some simple ‘scripting’. 

2.      Secondly, we’re going to put together a much more advanced REALTOR application suitable for Real-estate professionals.  It will allow us to easily search for and find properties that match certain user-defined criteria.  It will allow us to display photos of the homes. 

3.      Then we’ll create a program that’s not a database application at all!  We’re going to create a working CALCULATOR!  Cool huh?

But first, let’s brush up on some basics:

Forms are made up of a variety of controls.  Currently, abcDB™ supports the following controls (See Appendix D for details on each control)

 Despite that fact that each of these controls are quite different, they all expose ‘properties’, and react to certain ‘events’.   As an abcDB™ ‘programmer’, you can create applications by modifying their properties, and by creating ‘script’ code that is executed in these control ‘events’.  You’ll see how this is accomplished later on in this chapter.

abcDB™ forms and the controls mentioned above contain MANY different properties.  It may seem overwhelming at first.  You may wonder … “How can I possibly learn all of these properties and events?!”

Fortunately, many of the properties you’ll find recur in many or all of the above controls.  For example, two properties that every control uses are TOP and LEFT.  These two properties obviously determine the location of the control.  And EVERY one of abcDB™’s controls contains these two properties.  Not so tough huh?

First of all, to view the PROPERTIES of any control, all you need to do is the following:

1.      EDIT an existing form OR create a NEW form.

2.      Select the control you want to view properties for.

3.      In the bottom-right corner of the form-builder screen, you'll see all the properties for the currently selected control:

As you can see in the above screen shot, we’re looking at some of the properties for a DROPDOWN box.  You can see that there are HEIGHT, WIDTH, LEFT (X), and TOP(Y) properties, among others.  These 4 properties are common to all controls.  Before proceeding, it would be appropriate to examine the information found in Appendix D.  There you will find ALL the properties and events that can be utilized while building forms.  When you feel comfortable with the controls and their individual properties/events, come back here and continue.

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