Building an Application – Página: 4 – 4GL APPLICATION FRAMEWORK

FORM SET SCROLL

Establishes a scrolling association between a form and a result set.

Syntax

FORM SET SCROLL [ NOCLEAR] form FROM set [LET clause] [EVALUATE clause]

Parameters

NOCLEAR	Specifies that form is not to be immediately initialized with data from set.
form	The form through which records are to be scrolled. Form must be open in the current window; it can be a multi-instance form in a display object.
set	A result set whose records are to be scrolled through form.

Comments

The current member of set is placed in the first instance of form. Subsequent members of set are placed in subsequent instances of form (if any).

Although many scrolling relationships can exist at one time, one set cannot have a scrolling relationship with more than one form at a time.

The application user scrolls the form through the records in set by moving the focus to the form and pressing a SCROLL key. If the focus is not located in an active scrolling form, but active scrolling forms exist in the display, then pressing a SCROLL key causes all active scrolling forms to scroll over their associated sets.

Example

To establish a scrolling relationship between the fEmps form and the result set EmpSet, enter

find all Employees where Location="New York" sorted by Name -> EmpSet
form open dEmps
form set scroll fEmps from EmpSet

WINDOW DISPLAY

Controls the display of windows on the screen.

Syntax

WINDOW DISPLAY [window] [EXPOSE|HIDE]

Parameters

window	Window can be name The name of an open window. The software looks up the value of name in the currently accessed directories in the usual way. A compiled command using name contains the unambiguous name of the window (including a reference to an application directory) that was found at compile time. (expr ) A character string, or an expression that evaluates to a character string, that is to be used at run time as a window object name. The parentheses must be entered. A compiled command using (expr) can refer to many windows, at the risk of encountering an ambiguous window name (i.e., no directory specified when versions of the window are available in two or more directories). If neither name nor (expr) is specified, the current window is assumed.
EXPOSE	Specifies that the window is to be displayed over any other active windows already on the screen. This is the default.
HIDE	Specifies that the window is to be displayed beneath any other active windows already on the screen.

Comments

The WINDOW DISPLAY command enables an application program to lift a particular window atop other active windows (using EXPOSE) or to drop the window below all other active windows (using HIDE).

An application user can also lift a window by interacting with it.

Example

To display the window wHelp underneath the other active windows:

window display wHelp hide

See Also

FORM DEFINE

Invokes Zim IDE to edit a form.

Syntax

FORM DEFINE formname [[IN] dirname]

Parameters

formname

The name of a new or existing form.

dirname

The name of the application directory in which the specified form can exist. If the form does not exist in the provided application directory, it will be created there.

If omitted:

the form will be selected from the first application directory in which it exists.

if the form does not exist, it will be created in the ZIM application directory.

Examples

Invokes Zim IDE to edit the form fAddEmps:

form define fAddEmps

If fAddEmps does not exist in any application directory, it will be created in the ZIM application directory.

Otherwise, it will be selected from the first application directory in which it exists.

form define fAddEmps ZIM

If fAddEmps does not exist in the ZIM application directory, it will be created there.

It will be selected from the ZIM application directory only if it exists there.

form define fAddEmps EMPS

If fAddEmps does not exist in the EMPS application directory, it will be created there.

It will be selected from the EMPS application directory only if it exists there.

MENU DEFINE

Invokes Zim IDE to edit a menu.

Syntax

MENU DEFINE menuname [[IN] dirname]

Parameters

menuname

The name of a new or existing menu.

dirname

The name of the application directory in which the specified menu can exist. If the menu does not exist in the provided application directory, it will be created there.

If omitted:

the menu will be selected from the first application directory in which it exists.

if the menu does not exist, it will be created in the ZIM application directory.

Examples

Invokes Zim IDE to edit the menu mAddEmps:

menu define mAddEmps

If mAddEmps does not exist in any application directory, it will be created in the ZIM application directory.

Otherwise, it will be selected from the first application directory in which it exists.

menu define mAddEmps ZIM

If mAddEmps does not exist in the ZIM application directory, it will be created there.

It will be selected from the ZIM application directory only if it exists there.

menu define mAddEmps EMPS

If mAddEmps does not exist in the EMPS application directory, it will be created there.

It will be selected from the EMPS application directory only if it exists there.

Syntax

WINDOW DEFINE winname [[IN] dirname]

Parameters

winname

The name of a new or existing window.

dirname

The name of the application directory in which the specified window can exist. If the window does not exist in the provided application directory, it will be created there.

If omitted:

the window will be selected from the first application directory in which it exists.

if the window does not exist, it will be created in the ZIM application directory.

Examples

Invokes Zim IDE to edit the window wAddEmps:

window define wAddEmps

If wAddEmps does not exist in any application directory, it will be created in the ZIM application directory.

Otherwise, it will be selected from the first application directory in which it exists.

window define wAddEmps ZIM

If wAddEmps does not exist in the ZIM application directory, it will be created there.

It will be selected from the ZIM application directory only if it exists there.

window define wAddEmps EMPS

If wAddEmps does not exist in the EMPS application directory, it will be created there.

It will be selected from the EMPS application directory only if it exists there.

DISPLAY DEFINE

Invokes Zim IDE to edit a display.

Syntax

DISPLAY DEFINE displayname [[IN] dirname]

Parameters

displayname

The name of a new or existing display.

dirname

The name of the application directory in which the specified display can exist. If the display does not exist in the provided application directory, it will be created there.

If omitted:

the display will be selected from the first application directory in which it exists.

if the display does not exist, it will be created in the ZIM application directory.

Examples

Invokes Zim IDE to edit the display dAppEmps:

display define dAppEmps

If dAppEmps does not exist in any application directory, it will be created in the ZIM application directory.

Otherwise, it will be selected from the first application directory in which it exists.

display define dAppEmps ZIM

If dAppEmps does not exist in the ZIM application directory, it will be created there.

It will be selected from the ZIM application directory only if it exists there.

display define dAppEmps EMPS

If dAppEmps does not exist in the EMPS application directory, it will be created there.

It will be selected from the EMPS application directory only if it exists there.

WINDOW MOVE

Moves a window to a new location on the screen.

Syntax

WINDOW MOVE [window] TO position [EXPOSE|HIDE]

Parameters

window	Window can be name The name of an open window. The software looks up name in the currently accessed directories in the usual way. A compiled command using name contains the unambiguous name of the window (including a reference to an application directory) that was found at compile time. (expr ) A character string, or an expression that evaluates to a character string, that is to be used at run time as a window object name. The parentheses must be entered. A compiled command using (expr) can refer to many windows, at the risk of encountering an ambiguous window name (i.e., no directory specified when versions of the window are available in two or more directories). If neither name nor (expr) is specified, the current window is assumed.
position	Position specifies the new location of the upper edge and left-hand edge of the window, and also changes the values for the system variables ThisWindow.WindowRow and ThisWindow.WindowCol. A window’s position is always relative to its physical parent. The physical parent of a clipped window is another window (parentwin). The physical parent of a pop-up window is the terminal. If position is such that the window moves out of bounds, it is automatically adjusted so that the window remains entirely within the parent’s boundaries.
EXPOSE	(DEFAULT) Specifies that the window is to be displayed over any other active windows already on the screen.
HIDE	Specifies that the window is to be displayed beneath any other active windows already on the screen.

Comments

The WINDOW MOVE command enables an application program to establish a new location for an open window.

If the specified window is active, it is displayed in its new position. If the window is open but not active, the WINDOW MOVE command establishes the position at which the window is to appear when activated.

Example

To move the window wStateCodes to a specified location, enter the following command:

window move wStateCodes to 200 400

See Also

WINDOW ACTIVATE

Makes an open window available for viewing and interaction by the application user.

Syntax

WINDOW ACTIVATE [window] [EXPOSE|HIDE]

Parameters

window	Window can be name The name of an open window. The software looks up name in the currently accessed directories in the usual way. A compiled command using name contains the unambiguous name of the window (including a reference to an application directory) that was found at compile time. (expr ) A character string, or an expression that evaluates to a character string, that is to be used at run time as a window object name. The parentheses must be entered. A compiled command using (expr) can refer to many windows, at the risk of encountering an ambiguous window name (i.e., no directory specified when versions of the window are available in two or more directories). If neither name nor (expr) is specified, the current window is assumed.
EXPOSE	(DEFAULT) Specifies that the window is to be displayed over any other active windows already on the screen.
HIDE	Specifies that the window is to be displayed beneath any other active windows already on the screen.

Comments

WINDOW ACTIVATE makes an open window visible on the terminal screen so that the application user can interact with the window. Note, however, that an input request relating to an inactive window (from a FORM INPUT, INPUT, or MENU INPUT command) automatically activates that window.

WINDOW ACTIVATE does not make the specified window the current window. If the specified window is already the current window, it remains the current window.

Separating the opening of a window (WINDOW OPEN) from the presentation of a window to the application user (WINDOW ACTIVATE) enables you to prepare the window and its contents before making the window visible. Similarly, you can keep a window open for long periods of time, activating it only when needed.

Example

window open wContracts

menu open mContracts

menu display

form open fContracts

form display

window activate

Opens a window, and then opens and displays a menu and form in the window. Once the window is initialized, the WINDOW ACTIVATE command presents it to the application user.

window open wTrace

…other commands…

window activate wTrace

…other commands…

window deactivate wTrace

Activates a trace window when it is required.

See Also

FORM SET LIST

Setting Contents of List Boxes and Combo Boxes

Introduction

In this module, we will explore how to set the contents of list boxes and combo boxes in forms. This is a fundamental skill for creating dynamic and interactive web forms. We will cover two methods: using an expression and using a set.

Method 1: Using an Expression

Command: FORM SET LIST formfield LIST expression

Parameters:

formfield: The target list box or combo box in your form.
expression: A character string or an expression that evaluates to a character string. Items in the expression must be separated by semicolons.

Example:

form set list fCDLFind.FieldName \
list " ProdCode ; ProdDesc ; UnitPrice ; QOH ; MinQty"

In this example, the combo box fCDLFind.FieldName is populated with field names specified in the string.

Method 2: Using a Set

Command: FORM SET LIST formfield FROM [ num ] [ setspec ] [FORMAT expression]

Parameters:

formfield: The target list box or combo box in your form.
num: The number of items to set in the list box or combo box. This can be an integer, a variable, or the word ALL.
setspec: A set specification whose members are used to set the contents of the list box or combo box. If omitted, the current set is used.
expression: An expression to format each item. This can be omitted if setspec is an unstructured application document.

Example:

form set list fCustomer.StateTab from states sorted by StCode \
format $ concat(StCode, " ", StDesc)

In this example, the list box fCustomer.StateTab is populated with state codes followed by state names, sorted by StCode.

Key Points to Remember

When using an expression, ensure items are separated by semicolons.
When using a set, you can specify the number of items and format each item using an expression.
Data populated from a set is left-justified regardless of data type.

Practice Exercise

Try setting the contents of a list box in your form using both methods. Experiment with different expressions and sets to see how the contents change.

See Also

FORM DISPLAY

Displays some or all of the form fields of the currently open form or display in the current window.

Syntax

FORM DISPLAY [ option ] [ object ]

Parameters

option

Can be
BELL
Sounds the terminal bell when the FORM DISPLAY command is executed. On older machines, the PC bell is rung. Newer machines must be equipped with a sound card and speakers in order for you to hear the bell.
INPUT
Shifts focus to the form and puts the application user in control of the interface after the FORM DISPLAY command is executed.
NOCLEAR
Prevents the contents of the window from being cleared before the FORM DISPLAY is carried out. Otherwise, the current window is cleared automatically.
NOLABEL
Prevents the contents of the current window from being cleared, and displays all specified fields that contain a visible value.
NOVAR
Prevents the contents of the current window from being cleared, and displays all specified fields that have no visible value.
PURGE
Specifies unprocessed input received before the form was displayed is to be ignored. Eliminates the possible effects of inadvertent keystrokes or mouse actions.

object

Can be
form
The name of the currently open form or display. Specify a particular instance of a form in brackets beside the object’s name.
formfield
The name of a particular form field within the currently open form or display. Specify a particular instance of a form field in brackets beside the form field’s name.
([exp1 ],[exp2 ],[exp3 ])
Positive integers or expressions that evaluate to positive integers, that identify a particular form or form field. Exp1 identifies the form number; exp2, the field number; exp3, the instance of the form or form field in the display. At a minimum, either exp1 or exp2 must be specified.

Comments

The current window must be activated (WINDOW ACTIVATE) for the displayed objects to be visible.
FORM DISPLAY displays form fields with values as they exist at the time the command is executed. If the application program changes the value of a field, the field must be re-displayed if the application user is to see the change.
A masked field that has no data value is displayed without the mask if the field is unavailable to the application user (i.e., protected or guarded). The mask of such a field is shown or suppressed when its availability changes (as a result of the FORM SET command).

Example

form display fGrandTot fInvItem.InvItemTot

Redisplays all fields of one form, and one field of another form.

form display input bell (2,,5)

Sounds the bell while re-displaying all form fields in the fifth instance of form number 2.
Name of the application directory in which the specified object can exist. If the dirname is omitted, the object can be created in any number of directories.

Syntax

Parameters

Comments

Example

See Also

Syntax

Parameters

Comments

Example

Syntax

Parameters

Examples

Related topics

Syntax

Parameters

Examples

Related topics

Syntax

Parameters

Examples

Related topics

Syntax

Parameters

Examples

Related topics

Syntax

Parameters

Comments

Example

Syntax

Parameters

Comments

Example

Setting Contents of List Boxes and Combo Boxes

Introduction

Method 1: Using an Expression

Method 2: Using a Set

Key Points to Remember

Practice Exercise

Syntax

Parameters

Comments

Example

See Also