The Input Process

An input process allows users to enter, modify, delete, and inquire about data in an application. Included in the basic information you provide for an input process is the Process Control File (called the PCF) associated with the process. For example, the PCF for a customer file maintenance input process would be the CUSTOMER file. Each input process can have at most one PCF.

Each input process consists of one or more frames (refer to the description of process components later in this chapter). For example, if a file has more input items than will fit on a single screen, you can define two frames that operate one after the other so the users can enter all of the required information.

Each frame may have one or more alternate images (also described in more detail later), which are the screen representations that appear to the users. If more than one image has been defined, one of them is selected to display based on previous user input.

A complete input process provides many different event points (described later) at which you can incorporate an ILF routine (set of statements) to supplement the basic process specifications. For example, you may want to calculate an extended price based upon the unit price and the quantity entered by a user.

As with a menu process, you paint the images that are to appear in an input process. Within the context of the Image Editor, you specify where each input item (user-entered field) is to appear. APPX automatically references the data dictionary to validate each item you paint, and displays the field as a series of “pseudo blanks” based on its length defined in the dictionary. The image editor also allows you to define any of several characteristic attributes, such as bright, inverse, and underline, for both items and background text.

Although the data dictionary already contains information about how a field should be formatted on an image (its default display mask), you can override this on each image. For example, you may want to display a date field, normally displayed as “12/31” (MM/DD), as “December 31”.

There are many other optional or automatic features provided in an input process including:

·    Data lookup to retrieve and optionally display data from another related file (such as, in an order entry process, using a CUSTOMER ID to look up and display a name from the CUSTOMER file).

·    Automatic retrieval of the next record on the file each time a user completes an input action.

·    Partial key option, by which you designate whether a user can enter a partial key or needs to enter a full key to identify a record on file.

·    Automatic update and/or deletion of records in related files. If so specified, APPX effectively allows a user to change key values in one or several associated files.

·    Automatic field validation against the data dictionary when data is entered by a user.

·    Scrolling of records. Each frame and a selected alternate image may appear once or, you can specify that it scrolls. APPX supports both vertical and horizontal scrolling.

Refer to Chapter 3-6: Input Processes for detailed specifications on defining these processes.