(Windows only)

The SYSTEM-HELP statement calls the Microsoft Windows Help engine to display Windows Help topics, and the HTML Help engine to display HTML Help topics.

Note: Does not apply to SpeedScript programming.

Syntax

SYSTEM-HELP file-string 
  [ WINDOW-NAME window-name ]
  {   CONTENTS
    | CONTEXT int-expr 
    | HELP-TOPIC string 
    | KEY string 
    | ALTERNATE-KEY string 
    | POSITION X x Y y WIDTH dx HEIGHT dy 
    | POSITION MAXIMIZE
    | QUIT
    | SET-CONTENTS int-expr 
    | CONTEXT-POPUP int-expr 
    | PARTIAL-KEY string 
    | MULTIPLE-KEY char TEXT string 
    | COMMAND string 
    | FINDER
    | FORCE-FILE
    | HELP
  }
file-string

The file-string parameter is a character expression that specifies the pathname of a help file. If the file has a .chm extension (the extension for compiled Microsoft HTML Help files), the Microsoft HTML Help viewer is launched. If the file has a .hlp file extension, the Microsoft Windows Help viewer is launched. The pathname can contain Unicode characters. See Internationalize ABL Applications for more information about Unicode.

WINDOW-NAME window-name

This option is supported for Windows Help (.hlp files) only.

The window-name parameter is a character expression that evaluates to the primary or secondary window name as defined in the [WINDOWS] section of the help project file. If the window name is omitted, or if "main" is specified, the primary help window is used.

CONTENTS

Supported only for backward compatibility.

For HTML Help, this option displays the Microsoft HTML Help viewer with the default topic in the content pane. Use the HELP-TOPIC option to specify the topic to display.

For Windows Help, this option displays the help topic defined as the contents in the [OPTIONS] section of the help project file.

CONTEXT int-expr

Displays the help topic that the context number identifies. You define context numbers in the [MAP] section of the help project file.

The int-expr parameter is the context number for the help topic.

HELP-TOPIC string

This option is supported for HTML Help (.chm files) only.

Displays a help topic in the content pane of the Microsoft HTML Help viewer.

The string parameter is a character expression that indicates the topic (.htm/.html file) within the compiled Microsoft HTML Help (.chm) file to display.

KEY string

For HTML Help, this option displays the topic matching the string found in the keyword index. Use semicolons in the string parameter to delimit multiple keywords. If no match is found, Microsoft HTML Help displays the help viewer with the Index tab on top.

For Windows Help, this option displays the help topic matching the string found in the index keyword list. If there is more than one match, it displays the first topic containing the keyword. If there is no match or the string is omitted, a message is displayed indicating that the keyword is invalid. The string parameter is a character expression that evaluates to a keyword for the desired help topic.

ALTERNATE-KEY string

This option is supported for HTML Help (.chm files) only. For Windows Help (.hlp files), see the MULTIPLE-KEY option.

Displays a help topic matching the string found in the alternate keyword (Alink) index.

The string parameter is a character expression that evaluates to a keyword in the alternate keyword index.

POSITION X x Y y WIDTH dx HEIGHT dy

Positions an existing (already opened) help window as specified.

The x parameter is an integer expression that specifies the x coordinate for the help window.

The y parameter is an integer expression that specifies the y coordinate for the help window.

The dx parameter is an integer expression that specifies the width of the help window.

The dy parameter is an integer expression that specifies the height of the help window.

Note: The coordinates used in the SYSTEM-HELP statement are coordinates used by the Windows Help system (not pixel coordinates). The Windows Help system divides the screen into 1024 units in each direction. For example, if the screen resolution is 1280 x 1024, the coordinates are 1.25 pixels wide (1280 / 1024) on the horizontal axis and 1 pixel tall (1024 / 1024) on the vertical axis. Thus, setting the position to (10, 10) places the help window at (12, 10). The horizontal position is 12 because 10 * 1.25 = 12.5 (truncated to 12 since there are no fractional pixels).
POSITION MAXIMIZE

Maximizes an existing (already opened) help window.

QUIT

Informs the help application that help is no longer required. If no other applications are using help, the operating system closes the help application.

SET-CONTENTS int-expr

Supported only for backward compatibility. This option is supported for Windows Help (.hlp files) only.

Dynamically re-maps the contents help topic from what is defined in the [OPTIONS] section of the help project file. When a CONTENTS call is made, the new contents help topic is displayed.

The int-expr parameter is the context number for the new contents help topic.

CONTEXT-POPUP int-expr

This option is supported for Windows Help (.hlp files) only.

Displays the help topic in a pop-up window that the context number identifies. You define context numbers in the [MAP] section of the help project file. If a non-scrolling region exists in a help topic, only that region displays when you use the CONTEXT-POPUP option to display the topic.

The int-expr parameter is the context number for the help topic.

PARTIAL-KEY string

This option is supported for Windows Help (.hlp files) only.

Displays the help topic matching the string found in the keyword list. In Windows, if there is more than one match, no match, or if the string is omitted, it displays the Help Topics: Window Help Topics dialog box with the Index tab on top.

The string parameter is a character expression that evaluates to a partial key for the desired help topic.

MULTIPLE-KEY char TEXT string

This option is supported for Windows Help (.hlp files) only. For HTML Help, see the ALTERNATE-KEY option.

Displays the help topic matching a keyword from an alternate keyword table.

The char parameter is a character expression that evaluates to the single character keyword table identifier for the required table.

The string parameter is a character expression that evaluates to the keyword that is located in the keyword table.

COMMAND string

This option is supported for Windows Help (.hlp files) only.

Executes a help macro.

The string parameter is a character expression that evaluates to the help macro to execute.

FINDER

This option is supported for Windows Help (.hlp files) only.

Displays the Help Topics: Windows Help Topics dialog box, which contains an Index tab, a Find tab, and optionally a Contents tab, with the most recently used tab displayed on top.

If a Contents tab file (.CNT file) is present when you initially call the Help Topics: Windows Help dialog box, then the Content tab displays on top. However, if a .CNT file is not present, then the dialog box displays with the Index tab on top; the Contents tab is not available.

FORCE-FILE

This option is supported for Windows Help (.hlp files) only.

Ensures that the correct help file is open and displayed.

HELP

This option is supported for Windows Help (.hlp files) only.

Displays the contents of the ABL Help-on-Help file. In Windows, HELP displays the Help Topics: Windows Help Topics dialog box.

Example

The following example demonstrates several features of the SYSTEM-HELP statement with the Procedure Editor help file (editeng.chm). The user can select a button to demonstrate each of the following SYSTEM-HELP options: CONTEXT, KEY, ALTERNATE-KEY, POSITION, POSITION-MAXIMIZE, and QUIT.

To execute this procedure, first copy the editeng.chm file from DLC\prohelp to your current working directory (by default, C:\OpenEdge\WRK). Then open and run r-syshlpchm.p in the Procedure Editor.

r-syshlpchm.p 

DEFINE VARIABLE helpfile AS CHARACTER NO-UNDO.

DEFINE BUTTON b_context LABEL "CONTEXT Call".
DEFINE BUTTON b_blank   LABEL "KEY Call-''".
DEFINE BUTTON b_single  LABEL "KEY Call-'Tools'".
DEFINE BUTTON b_full    LABEL "KEY Call- Tools;Menu".
DEFINE BUTTON b_max     LABEL "POSITION MAXIMIZE Call".
DEFINE BUTTON b_pos     LABEL "POSITION Call".
DEFINE BUTTON b_alt     LABEL "ALTERNATE-KEY Call".
DEFINE BUTTON b_quit    LABEL "QUIT Call".

FORM 
  SKIP(1) SPACE(1) b_context SPACE(1)
  SKIP(1) SPACE(1) b_blank SPACE(1)
  SKIP(1) SPACE(1) b_single SPACE(1)
  SKIP(1) SPACE(1) b_full SPACE(1)
  SKIP(1) SPACE(1) b_max SPACE(1)
  SKIP(1) SPACE(1) b_pos SPACE(1)
  SKIP(1) SPACE(1) b_alt SPACE(1)
  SKIP(1) SPACE(1) b_quit SPACE(1)
  SKIP(1) WITH FRAME x.
ENABLE ALL WITH FRAME x.

helpfile = "editeng.chm".

/* The CONTEXT call displays the help topic associated with the specified
   context number of a help topic (in this case, 49256, for the Using Editor
   Buffers topic). */
ON CHOOSE OF b_context IN FRAME x DO:
  SYSTEM-HELP helpfile CONTEXT 49256.
END.

/* The KEY call brings up the topic matching the string found in the keyword
   index. If the string parameter is empty or is omitted altogether, the help
   viewer displays with the Index tab on top.*/
ON CHOOSE OF b_blank IN FRAME x DO:
  SYSTEM-HELP helpfile KEY "".
END.

/* In a KEY call where the string parameter does not exactly match an index
   keyword of any help topic, the fill-in at the top of the Index tab is
   populated with the string that is passed in, and the default help topic 
   is displayed. */
ON CHOOSE OF b_single IN FRAME x DO:
  SYSTEM-HELP helpfile KEY "Tools".
END.

/* In a KEY call where the string parameter exactly matches a unique index
   keyword of a help topic, the help engine automatically launches a help
   viewer window and displays the matching topic. Use semicolons to delimit
   multiple keywords.*/
ON CHOOSE OF b_full IN FRAME x DO:
  SYSTEM-HELP helpfile KEY "Tools;Menu".
END.

/* In an ALTERNATE-KEY call works like the KEY call but it uses the alternate
   keyword (Alink) index, if one is provided. */
ON CHOOSE OF b_alt IN FRAME x DO:
  SYSTEM-HELP helpfile ALTERNATE-KEY "Tools Menu".
END.

/* The POSITION X x Y y WIDTH dx HEIGHT dy call positions the open help window
   as specified */
ON CHOOSE OF b_pos IN FRAME x DO:
  SYSTEM-HELP helpfile POSITION X 2 Y 2 WIDTH 450 HEIGHT 450.
END.

/* The POSITION MAXIMIZE call maximizes the open help window as specified*/
ON CHOOSE OF b_max IN FRAME x DO:
  SYSTEM-HELP helpfile POSITION MAXIMIZE.
END.

/* The QUIT call causes the help engine to terminate, unless another
   application is using help. */
ON CHOOSE OF b_quit IN FRAME x DO:
  SYSTEM-HELP helpfile QUIT.
  RETURN.
END.

WAIT-FOR GO OF FRAME x.

See also

FILE-INFO system handle, SEARCH function