Topic group

The process of designing forms involves clarifying the specific needs of your application, identifying the information you want to work with, and then devising a design that best meets your needs. This section briefly describes the process.

Goal of form design

The goal of form design is to display and obtain the information you need in an accessible, efficient manner. The form should encapsulate data so that it may be run without affecting other forms that use the same data. dBASE Plus makes this simple.

It’s important for your design to provide users with the information they need and clearly tell them what they need to do to successfully complete a task. A well-designed form has visual appeal that motivates users to use your application. In addition, it should use limited screen space efficiently.

Purpose of a form

Each form in your application should serve a clear, specific purpose. Forms are commonly used for the following purposes:

Data entry forms provide access to data in one or more tables. Users can retrieve, display, and change information stored in tables.

Dialog boxes display status information or ask users to supply information or make a decision before continuing with a task. A typical feature of a dialog box is the OK button, which the user clicks to process the selected choices.

Application windows contain an entire application that users can launch from an icon off the Windows Start menu.

You should be able to explain the purpose of a form in a single sentence. If a form serves multiple purposes, consider creating a separate form for each.

Some guidelines for data entry forms

When designing data entry forms, consider the following guidelines:

If data resides in multiple tables, use a query or data module that defines the relationships among tables.

If users need access to only some of the information in a table, use a query or data module that selects only the records and fields you want.

Determine the order in which users will want to display records, for example, alphabetically, chronologically, or by customer number. Use a query with indexes that arrange records in the order the users will want.

Identify tasks users will perform when working with data on the form, and provide menus, pushbuttons, and toolbar buttons that users can choose to initiate tasks.

When designing a form, you can provide validation criteria on a field-by-field basis. Use the following questions to help decide which criteria you need.

Do you require an entry for the field, or can users leave it blank?

Are duplicate entries allowed?

Must the data fall within a valid range?

Must the data appear in a specific, fixed format, such as a phone number?

Are valid entries limited to a list of values? If valid entries are not limited to a list of values, you can speed up data entry by compiling and displaying a list of frequently entered values which also allows users to enter companies not on the list?

You can also provide form-level validation in a canClose event. This event returns True or False based on a condition you specify. If the condition is not met, the form will not close. For example, you could use canClose if a user has not saved the last row entered. In the method you write for this event, you would ask if the user wants to save the data and, if yes, allow the user to do so.

You can associate some field types with particular controls. By default, each dBASE field type is associated with a specific control type. For example, a Numeric field type uses a spin box control by default. You can change these associations to make data entry easier and more efficient in your particular application. Right-click the Field palette, and choose Associate Component Types.

If your form needs to contain many fields or controls, consider using the Notebook component . Divide controls into related groups and list each group on a separate page of the notebook. Or use a multi-page form with buttons for page navigation. Or, instead of buttons, add a TabBox component and set various TabBox properties to create page tabs and name each page.

Designing the form layout

You can put controls anywhere on a form. However, the layout you choose determines how successfully users can enter data using the form. Here are a few guidelines to consider:

Put similar or related information together in a group, and use visual effects to emphasize the grouping. For example, put a company’s billing and shipping address information in separate groups. To emphasize a group, enclose its controls in a distinct visual area using a rectangle, lines, alignment, and colors.

On a form, the Tab and Shift-Tab keys move the focus from one control to another. Tab moves focus forward along the z-order, and Shift-Tab moves focus backward. Think about the order in which the user will be moving (tabbing) through these controls on the form. The basic pattern is from left to right, top to bottom. However, users may want to jump from one group of controls to the beginning of another group, skipping over individual controls.

Users are typically more productive when a screen is clean and uncluttered. If it appears you're trying to cram too much information onto a single form screen, consider using a form with multiple pages, or a main form with optional smaller forms that users can display on demand.