Application Techniques
General Techniques

In order for InfoMaker to recognize that a window in a library serves as the basis for a form style, you must specify a comment for the window that starts with the text Style:

Style: text that describes the style

The text that follows Style: is the text that displays below the icon for the form style in the New Form dialog box in InfoMaker.

For example, if you save a w_pbstyle_freeform window with the comment Style: Maintain corporate data in a style library, InfoMaker users see this when they create a new form:

You can specify the comment either when first saving the window or in the Library painter.

For more information about designing windows, see the section called “Working with Windows” in Users Guide.

The DataWindow controls with special names are the heart of a form. It is in these controls that users manipulate the data in the form.

You need to understand:

How the freeform DataWindow is sized

All form styles you build contain a freeform DataWindow (as do all the built-in styles). Regardless of what size you specify for the freeform DataWindow control in the Window painter in PowerBuilder, the freeform DataWindow fills the entire form in the Form painter in InfoMaker. InfoMaker enlarges the freeform DataWindow so that users can place data (such as computed fields) anywhere in the form.

This means that a window background color that you specify in PowerBuilder is ignored in the form.

Retrieving rows into the central DataWindow control

When an InfoMaker user runs a form, InfoMaker automatically populates the SQLCA Transaction object with the correct values, so you do not have to do that in a script. To retrieve rows into the central DataWindow control, all you have to do is set the Transaction object for the control and then retrieve rows.

For example, to retrieve data into the control named dw_freeform, code:

dw_freeform.SetTransObject(SQLCA)
dw_freeform.Retrieve()

You would code this in the window's Open event to present the data to the user when the form opens.

For more information about Transaction objects, see Using Transaction Objects.

All windows serving as the basis for a form style have at least one DataWindow control. In addition, you can add any other controls that you can add to standard PowerBuilder windows, such as command buttons, user objects, text, edit boxes, pictures, and drawing objects.

Users of the form can move the controls you place in the window, but they cannot delete them.

Users can also add controls to the form in the Form painter. They make CommandButtons and PictureButtons work by associating actions with them. Actions are described next.

Often users want to add buttons (CommandButtons or PictureButtons) to a form created using a custom form style. When you create the form style, you specify what the added buttons can do by defining actions for the form style. When users place a button, they select the desired action from a list:

Actions are implemented as public window-level functions.

You specify the menu and toolbar that display when users run a form by defining a menu in the Menu painter and associating it with the window that serves as the basis for your form style.

Each menu item in the menu you define displays when a form is run. In addition, InfoMaker adds Window and Help menus to allow users to manipulate windows and get online Help when running a form in the InfoMaker environment.

Item in a toolbar

As with MDI applications, you can specify that a menu item should display as an item in a toolbar when the form is run.

Scripting

You use the same scripting techniques for menus used in forms as you do for menus used in standard windows. Typically you communicate between a window and its menu by defining user events for the window, then triggering them from the menu using the menu object's ParentWindow property to refer to the form window; this technique is used in the built-in form styles.

For more information

For more information about using menus and user events, see Users Guide.

For more information about associating toolbars with menus, see Building an MDI Application

You write scripts for the window, its controls, and Menu objects the same way you write them for standard windows and menus. When working with DataWindow controls, remember that you do not have to set the properties of the SQLCA Transaction object -- InfoMaker does that automatically when users run a form.

You can define global user-defined functions and structures to support the scripts you code, but note that since InfoMaker does not have an application object, form styles cannot use global variables or global external function declarations.

You can make forms as sophisticated as you want. For example, you can implement drag and drop features, and mail-enable your form.

For complete information about the features you can build into a window, see the the section called “Working with Windows” in Users Guide.

When an InfoMaker user using the style library creates a new form, all custom form styles display in the Form Style box in the New Form dialog box:

Custom styles display with a generic icon.

InfoMaker users simply select a data source and a custom style to start building a form based on your form style. You should provide documentation to users of your form styles.

Understanding inheritance

When users build a form, they are working with a window that is a descendant of the window that you built for the form style. That is, the form style window you built in PowerBuilder is the ancestor, and the form window used in InfoMaker is the descendant. This means that if you change the form style, the changes are picked up the next time users work with a form using that style.

For example, you can add controls to the form style and have the controls display automatically when users later open existing forms using the style.

You can store style libraries on the network to make them readily available to all InfoMaker users. You do this with a shared initialization file on a network: you place an InfoMaker initialization file that references the shared style libraries out on the network, then set up InfoMaker users so that they can access the initialization file.

Specifying the location of the shared InfoMaker initialization file in InfoMaker

Once the shared initialization file has been defined in a user's InfoMaker initialization file, the user's style library search path consists of the style libraries defined in the user's local InfoMaker initialization file plus all style libraries defined in the shared initialization file. When the user creates a new form, the form styles defined in all the style libraries display in the New Form dialog box.

Each InfoMaker user needs to tell InfoMaker where to find the shared initialization file.

Preventing the use of built-in styles

You might not want the built-in form styles to be available to InfoMaker users. That is, you might want all forms to be based on one of your organization's user-defined styles. You can ensure this by suppressing the display of the built-in styles in the New Form dialog box.