Col()

 

COL()

Returns the current screen column position

Syntax

      COL()  --> nPosition

Arguments

None.

Returns

<nPosition> Current column position

Description

This function returns the current cursor column position. The value for this function can range between 0 and MAXCOL().

Examples

      ? Col()

Compliance

Clipper

Platforms

All

Files

Library is rtl

Seealso

ROW(), MAXROW(), MAXCOL()

C5_ROW

 ROW()
 Return the screen row position of the cursor
------------------------------------------------------------------------------
 Syntax

     ROW() --> nRow

 Returns

     ROW() returns the cursor row position as an integer numeric value.  The
     range of the return value is zero to MAXROW().

 Description

     ROW() is a screen function that returns the current row or line position
     of the screen cursor.  The value of ROW() is updated by both console and
     full-screen commands and functions.  @...SAY only updates ROW() when the
     current DEVICE is the SCREEN.

     ROW() is used with COL() and all variations of the @ command to position
     the cursor to a new line relative to the current line.  In particular,
     you can use ROW() and COL() to create screen position-independent
     procedures or functions where you pass the upper-left row and column as
     parameters.

     ROW() is related to PROW() and PCOL(), which track the current printhead
     position instead of the screen cursor position.

 Examples

     .  In this example, ROW() simulates the LIST command, displaying
        text on the same line but in different columns:

        LOCAL nRow
        USE Customer INDEX CustName NEW
        DO WHILE .NOT. EOF()
           CLS
           @ 1, 1 SAY PADR("Name", LEN(CustName))
           @ ROW(), COL() + 2 SAY PADR("Address", ;
                 LEN(Address))
           @ ROW(), COL() + 2 SAY PADR("Phone", LEN(Phone))
           nRow = 0
           DO WHILE nRow++ <= 15 .AND. (!EOF())
              @ ROW() + 1, 1 SAY CustName
              @ ROW(), COL() + 2 SAY Address
              @ ROW(), COL() + 2 SAY Phone
              SKIP
           ENDDO
           WAIT
        ENDDO
        CLOSE Customer

 Files   Library is CLIPPER.LIB.

See Also: ?|?? @…GET @…SAY PCOL() PROW()

 

C5 UI Commands & Functions

C5 User Interface Commands and Functions

Global Settings :

SET CENTURY :

Modify the date format to include or omit century digits

SET CENTURY on | OFF | <xlToggle>

SET COLOR* :

Define screen colors

SET COLOR | COLOUR TO [[<standard>]
    [,<enhanced>] [,<border>] [,<background>]
    [,<unselected>]] | (<cColorString>)

SET CONFIRM :

Toggle required exit key to terminate GETs

SET CONFIRM on | OFF | <xlToggle>

SET CONSOLE :

Toggle console display to the screen

SET CONSOLE ON | off | <xlToggle>

SET CURSOR :

Toggle the screen cursor on or off

SET CURSOR ON | off | <xlToggle>

SET DATE :

Set the date format for input and display

SET DATE FORMAT [TO] <cDateFormat>
SET DATE [TO] AMERICAN | ansi | british | french
    | german | italian | japan | usa

SET DECIMALS :

Set the number of decimal places displayed

SET DECIMALS TO [<nDecimals>]

SET DELIMITERS :

Toggle or define GET delimiters

SET DELIMITERS on | OFF | <xlToggle>
SET DELIMITERS TO [<cDelimiters> | DEFAULT]

SET DEVICE :

Direct @…SAYs to the screen or printer

SET DEVICE TO SCREEN | printer

SET EPOCH :

Control the interpretation of dates with no century digits

SET EPOCH TO <nYear>

SET FIXED :

Toggle fixing of the number of decimal digits displayed

SET FIXED on | OFF | <xlToggle>

SETBLINK() :

Toggle asterisk (*) interpretation in SET COLOR

SETBLINK([<lToggle>]) --> lCurrentSetting

SETCOLOR() :

Return the current colors and optionally set new colors

SETCOLOR([<cColorString>]) --> cColorString

SETCURSOR() :

Set the cursor shape

SETCURSOR([<nCursorShape>]) --> nCurrentSetting

SETMODE() :

Change display mode to specified number of rows and columns

SETMODE(<nRows>, <nCols>) --> lSuccess

SETPOS() :

Move the cursor to a new position

SETPOS(<nRow>, <nCol>) --> NIL

User Input :

CLEAR TYPEAHEAD :

Empty the keyboard buffer

CLEAR TYPEAHEAD

INKEY() :

Extract a character from the keyboard buffer

 
INKEY( [ <nSeconds> ] ) --> nInkeyCode

KEYBOARD :

Stuff a string into the keyboard buffer

KEYBOARD <cString>

LASTKEY() :

Return the INKEY() value of the last key in the buffer

LASTKEY() --> nInkeyCode

NEXTKEY() :

Read the pending key in the keyboard buffer

NEXTKEY() --> nInkeyCode

SET TYPEAHEAD :

Set the size of the keyboard buffer

SET TYPEAHEAD TO <nKeyboardSize>

Basic :

?/?? :

Display one or more values to the console

? | ?? [<exp list>]

@…BOX :

Draw a box on the screen

@ <nTop>, <nLeft>, <nBottom>, <nRight>
  BOX <cBoxString> [COLOR <cColorString>]

@…CLEAR :

Clear a rectangular region of the screen

@ <nTop>, <nLeft> [CLEAR
  [TO <nBottom>, <nRight>]]

@…SAY :

Display data at a specified screen or printer row and column

@ <nRow>, <nCol>
    [SAY <exp>
    [PICTURE <cSayPicture>]
    [COLOR <cColorString>]]
    GET <idVar>
    [PICTURE <cGetPicture>]
    [COLOR <cColorString>]
    [WHEN <lPreExpression>]
    [RANGE* <dnLower>, <dnUpper>] |
    [VALID <lPostExpression>]

@…TO :

Draw a single or double line box

@ <nTop>, <nLeft>
    TO <nBottom>, <nRight> [DOUBLE] [COLOR
    <cColorString>]

ACCEPT :

Place keyboard input into a memory variable

ACCEPT [<expPrompt>] TO <idVar>

INPUT :

Enter the result of an expression into a variable

INPUT [<expPrompt>] TO <idVar>

 

ALERT() :

Display a simple modal dialog box

ALERT( <cMessage>, [<aOptions>] ) --> nChoice

CLEAR SCREEN :

Clear the screen and home the cursor

CLEAR [SCREEN] | CLS

COL() :

Return the screen cursor column position

COL() --> nCol

COLORSELECT()

                Activate attribute in current color settings

   COLORSELECT(<nColorIndex>) --> NIL

DEVOUT() :

Write a value to the current device

DEVOUT(<exp>, [<cColorString>]) --> NIL

DEVOUTPICT() :

Write a value to the current device using a picture clause

DEVOUTPICT(<exp>, <cPicture>, [<cColorString>]) --> NIL

           DEVPOS() :

Move the cursor or printhead to a new position depending on the

current device

        DEVPOS(<nRow>, <nCol>) --> NIL

DISPBEGIN() :

Begin buffering screen output

DISPBEGIN() --> NIL

DISPBOX() :

Display a box on the screen

DISPBOX(<nTop>, <nLeft>, <nBottom>, <nRight>,
    [<cnBoxString>], [<cColorString>]) --> NIL

DISPCOUNT() :

Return the number of pending DISPEND() requests

DISPCOUNT() --> nDispCount

DISPEND() :

Display buffered screen updates

DISPEND() --> NIL

DISPOUT() :

Write a value to the display

DISPOUT(<exp>, [<cColorString>]) --> NIL

OUTERR() :

Write a list of values to the standard error device

OUTERR(<exp list>) --> NIL

OUTSTD() :

Write a list of values to the standard output device

OUTSTD(<exp list>) --> NIL

QOUT() :

Display a list of expressions to the console

QOUT([<exp list>]) --> NIL
QQOUT([<exp list>]) --> NIL

RESTORE SCREEN* :

Display a saved screen

RESTORE SCREEN [FROM <cScreen>]

RESTSCREEN() :

Display a saved screen region to a specified location

RESTSCREEN([<nTop>], [<nLeft>],
    [<nBottom>], [<nRight>], <cScreen>) --> NIL

ROW() :

Return the screen row position of the cursor

ROW() --> nRow

SAVE SCREEN* :

Save current screen to a buffer or variable

SAVE SCREEN [TO <idVar>]

SAVESCREEN() :

Save a screen region for later display

SAVESCREEN([<nTop>], [<nLeft>],
    [<nBottom>], [<nRight>]) --> cScreen

SCROLL() :

Scroll a screen region up or down

SCROLL([<nTop>], [<nLeft>],
     [<nBottom>], [<nRight>], [<nVert>] [<nHoriz>])
 --> NIL

TYPE :

Display or print the contents of a text file

TYPE <xcFile> [TO PRINTER] [TO FILE <xcOutFile>]

Advanced :

ACHOICE() :

Execute a pop-up menu

ACHOICE(<nTop>, <nLeft>, <nBottom>, <nRight>,
    <acMenuItems>,
    [<alSelectableItems> | <lSelectableItems>],
    [<cUserFunction>],
    [<nInitialItem>],
    [<nWindowRow>]) --> nPosition

BROWSE()* :

Browse records within a window

BROWSE([<nTop>], [<nLeft>],
    [<nBottom>], [<nRight>]) --> lSuccess

DBEDIT() :

Browse records in a table format

DBEDIT( [<nTop>], [<nLeft>],
    [<nBottom>], <nRight>],
    [<acColumns>],
    [<cUserFunction>],
    [<acColumnSayPictures> | <cColumnSayPicture>],
    [<acColumnHeaders> | <cColumnHeader>],
    [<acHeadingSeparators> | <cHeadingSeparator>],
    [<acColumnSeparators> | <cColumnSeparator>],
    [<acFootingSeparators> | <cFootingSeparator>],
    [<acColumnFootings> | <cColumnFooting>]) --> NIL

DISPLAY :

Display records to the console

DISPLAY <exp list>
    [TO PRINTER] [TO FILE <xcFile>]
    [<scope>] [WHILE <lCondition>]
    [FOR <lCondition>] [OFF]

LIST :

List records to the console

LIST <exp list>
    [TO PRINTER] [TO FILE <xcFile>]
    [<scope>] [WHILE <lCondition>]
    [FOR <lCondition>] [OFF]

LABEL FORM :

Display labels to the console

LABEL FORM <xcLabel>
    [TO PRINTER] [TO FILE <xcFile>] [NOCONSOLE]
    [<scope>] [WHILE <lCondition>] [FOR <lCondition>]
    [SAMPLE]

REPORT FORM :

Display a report to the console

REPORT FORM <xcReport>
    [TO PRINTER] [TO FILE <xcFile>] [NOCONSOLE]
    [<scope>] [WHILE <lCondition>] [FOR <lCondition>]
    [PLAIN | HEADING <cHeading>] [NOEJECT] [SUMMARY]

TEXT :

Display a literal block of text

TEXT [TO PRINTER] [TO FILE <xcFile>]
    <text>...
ENDTEXT

GET System :

Standard :

@…GET :

Create a new Get object and display it on the screen

@ <nRow>, <nCol>
    [SAY <exp>
    [PICTURE <cSayPicture>]
    [COLOR <cColorString>]]
    GET <idVar>
    [PICTURE <cGetPicture>]
    [COLOR <cColorString>]
    [WHEN <lPreExpression>]
    [RANGE* <dnLower>, <dnUpper>] |
    [VALID <lPostExpression>]

CLEAR GETS :

Release Get objects from the current GetList array

CLEAR GETS

READ :

Activate full-screen editing mode using Get objects

READ [SAVE]

READEXIT() :

Toggle Uparrow and Downarrow as READ exit keys

READEXIT([<lToggle>]) --> lCurrentState

READINSERT() :

Toggle the current insert mode for READ and MEMOEDIT()

READINSERT([<lToggle>]) --> lCurrentMode

READKEY()* :

Determine what key was used to terminate a READ

READKEY() --> nReadkeyCode

READMODAL() :

Activate a full-screen editing mode for a GetList

READMODAL(<aGetList>) --> NIL

READVAR() :

Return the current GET/MENU variable name

READVAR() --> cVarName

SET ESCAPE :

Toggle Esc as a READ exit key

SET ESCAPE ON | off | <xlToggle>

SET FORMAT :

Activate a format when READ is executed

SET FORMAT TO [<idProcedure>[.<ext>]]

SET INTENSITY :

Toggle enhanced display of GETs and PROMPTs

SET INTENSITY ON | off | <xlToggle>

SET SCOREBOARD :

Toggle the message display from READ or MEMOEDIT()

SET SCOREBOARD ON | off | <xlToggle>

UPDATED() :

Determine if any GET changed during a READ

UPDATED() --> lChange

Getsys.prg Functions :

GETACTIVE() :

Return the currently active Get object

GETACTIVE() --> objGet

GETAPPLYKEY() :

Apply a key to a Get object from within a Get reader

GETAPPLYKEY(<oGet>, <nKey>) --> NIL

GETDOSETKEY() :

Process SET KEY during Get editing

GETDOSETKEY(<oGet>) --> NIL

GETPOSTVALIDATE() :

Postvalidate the current Get object

GETPOSTVALIDATE(<oGet>) --> lSuccess

GETPREVALIDATE() :

Prevalidate a Get object

GETPREVALIDATE(<oGet>) --> lSuccess

GETREADER() :

Execute standard READ behavior for a Get object

GETREADER(<oGet>) --> NIL

READFORMAT() :

Return, and optionally set, the format file code block

READFORMAT([<bFormat>]) --> bCurrentFormat

READKILL() :

Return, and optionally set, the READ terminate flag

READKILL([<lKillRead>]) --> lCurrentSetting

READUPDATED() :

Return, and optionally set, whether a Get changed

READUPDATED([<lChanged>]) --> lCurrentSetting

GET Class :

Class Function :

GetNew() : Create a new Get object

Exported Instance Variables :

badDate : Indicates if the editing buffer contains an invalid date
block : Code block to associate Get with a variable
buffer : Character value that defines the editing buffer
cargo : User-definable variable
changed : Indicates whether the Get:buffer has changed
clear : Indicates whether the editing buffer should be cleared
col : Get column number
colorSpec : Display attributes string
decPos : Decimal point position within the editing buffer
exitState : Means by which the user exited the Get
hasFocus : Indicates whether or not the Get object has input focus
minus : Indicates whether or not a minus sign has been entered
name : Get variable name
original : Character string containing the original value of the Get
picture : PICTURE string
pos : Current cursor position within the editing buffer
postBlock : Code block to validate a newly entered value
preBlock : Code block to decide if editing is permitted
reader : Contains a block to affect READ behavior on a Get object
rejected : Indicates if last insert/overStrike character was rejected
row : Get row number
subscript : Information about array Get objects .
type : Get variable data type
typeOut : Indicates attempt to move the cursor out of editing buffer

Exported Methods :

State Change Methods :

assign() : Assigns the editing buffer contents to the Get variable
colorDisp() : Changes a Get object’s color and then redisplay it
display() : Displays the Get on the screen .
killFocus() : Takes input focus away from the Get object
reset() : Resets the internal state information of the Get
setFocus() : Gives input focus to the Get object
undo() : Sets the Get variable back to Get:original
unTransform() : Converts character value to its original data type
updateBuffer() : Updates the editing buffer and redisplays the Get
varGet() : Returns the current value of the Get variable
varPut() : Sets the Get variable to the passed value

Cursor Movement Methods :

end() : Moves the cursor to the rightmost position
home() : Moves the cursor to the leftmost position
left() : Moves the cursor left one character
right() : Moves the cursor right one character
toDecPos() : Moves the cursor to the immediate right of Get:decPos
wordLeft() : Moves the cursor left one word
wordRight() : Moves the cursor right one word

Editing Methods :

backspace() : Moves the cursor to the left and deletes one character
delete() : Deletes the character under the cursor
delEnd() : Deletes from current cursor position to the end of the Get
delLeft() : Deletes the character to the left of the cursor
delRight() : Deletes the character to the right of the cursor
delWordLeft() : Deletes the word to the left of the cursor
delWordRight() : Deletes the word to the right of the cursor

Text Entry Methods :

insert() : Inserts characters into the editing buffer
overStrike() : Overwrites characters in the editing buffer

Menu System :

@…PROMPT :

Paint a menu item and define a message

@ <nRow>, <nCol> PROMPT <cMenuItem>
     [MESSAGE <cExpression>]

MENU TO :

Execute a lightbar menu for defined PROMPTs

     MENU TO <idVar>

          MENUMODAL :

Activate a top bar menu

         MENUMODAL(<oTopBar>, <nSelection>, <nMsgRow>,
             <nMsgLeft>, <nMsgRight>, <cMsgColor>) --> MenuID

SET MESSAGE :

Set the @…PROMPT message line row

SET MESSAGE TO [<nRow> [CENTER | CENTRE]]

SET INTENSITY :

Toggle enhanced display of GETs and PROMPTs

SET INTENSITY ON | off | <xlToggle>

SET WRAP :

Toggle wrapping of the highlights in MENUs

SET WRAP on | OFF | <xlToggle>

Browse Classes :

TBrowse :

Provides objects for browsing table-oriented data.

Description :

A TBrowse object is a general purpose browsing mechanism for table-oriented data. TBrowse objects provide a sophisticated architecture for acquiring, formatting, and displaying data. Data retrieval and file positioning are performed via user-supplied code blocks, allowing a high degree of flexibility and interaction between the browsing mechanism and the underlying data source. The format of individual data items can be precisely controlled via the TBColumn data retrieval code blocks; overall display formatting and attributes can be controlled by sending appropriate messages to the TBrowse object.

A TBrowse object relies on one or more TBColumn objects. A TBColumn object contains the information necessary to define a single column of the browse table (see TBColumn class in this chapter).

During operation, a TBrowse object retrieves data by evaluating code blocks. The data is organized into rows and columns and displayed within a specified rectangular region of the screen. The TBrowse object maintains an internal browse cursor. The data item on which the browse cursor rests is displayed in a highlighted color. (The actual screen cursor is also positioned to the first character of this data item.)

Initially, the browse cursor is placed on the data item at the top left of the browse display. Messages can then be sent to the TBrowse object to navigate the displayed data, causing the browse cursor to move. These messages are normally sent in response to user keystrokes.

New data is automatically retrieved as required by navigation requests. When navigation proceeds past the edge of the visible rectangle, rows or columns beyond that edge are automatically brought into view. When new rows are brought into view, the underlying data source is repositioned by evaluating a code block.

Note: TBrowse objects do not clear the entire window before output during redisplay operations. Part of the window may still be cleared when data from the existing display is scrolled.

Class Functions :

TBrowseNew() :

Create a new TBrowse object

 TBrowseNew(<nTop>, <nLeft>, <nBottom>, <nRight>)
 --> objTBrowse

Returns a new TBrowse object with the specified coordinate settings. The TBrowse object is created with no columns and no code blocks for data positioning. These must be provided before the TBrowse object can be used.

TBrowseDB() :

Create a new TBrowse object for browsing a database file

 TBrowseDB(<nTop>, <nLeft>, <nBottom>, <nRight>)
 --> objTBrowse

Returns a new TBrowse object with the specified coordinate settings and default code blocks for data source positioning within database files. The default code blocks execute the GO TOP, GO BOTTOM, and SKIP operations.

Note that TBrowseDB() creates an object with no column objects. To make the TBrowse object usable, you must add a column for each field to be displayed

Exported Instance Variables:

autoLite : Logical value to control highlighting
cargo : User-definable variable
colCount : Number of browse columns
colorSpec : Color table for the TBrowse display
colPos : Current cursor column position
colSep : Column separator character
footSep : Footing separator character
freeze : Number of columns to freeze
goBottomBlock : Code block executed by TBrowse:goBottom()
goTopBlock : Code block executed by TBrowse:goTop()
headSep : Heading separator character
hitBottom : Indicates the end of available data
hitTop : Indicates the beginning of available data
leftVisible : Indicates position of leftmost unfrozen column in display
nBottom : Bottom row number for the TBrowse display
nLeft : Leftmost column for the TBrowse display
nRight : Rightmost column for the TBrowse display
nTop : Top row number for the TBrowse display
rightVisible : Indicates position of rightmost unfrozen column in display
rowCount : Number of visible data rows in the TBrowse display
rowPos : Current cursor row position
skipBlock : Code block used to reposition data source
stable : Indicates if the TBrowse object is stable

Exported Methods:

Cursor Movement Methods :

down() : Moves the cursor down one row
end() : Moves the cursor to the rightmost visible data column
goBottom() : Repositions the data source to the bottom of file
goTop() : Repositions the data source to the top of file
home() : Moves the cursor to the leftmost visible data column
left() : Moves the cursor left one column
pageDown() : Repositions the data source downward
pageUp() : Repositions the data source upward
panEnd() : Moves the cursor to the rightmost data column
panHome() : Moves the cursor to the leftmost visible data column
panLeft() : Pans left without changing the cursor position
panRight() : Pans right without changing the cursor position
right() : Moves the cursor right one column
up() : Moves the cursor up one row

Miscellaneous Methods :

addColumn() : Adds a TBColumn object to the TBrowse object
colorRect() : Alters the color of a rectangular group of cells
colWidth() : Returns the display width of a particular column
configure() : Reconfigures the internal settings of the TBrowse object
deHilite() : Dehighlights the current cell
delColumn() : Delete a column object from a browse
forceStable() : Performs a full stabilization .
getColumn() : Gets a specific TBColumn object
hilite() : Highlights the current cell
insColumn() : Insert a column object in a browse
invalidate() : Forces redraw during next stabilization
refreshAll() : Causes all data to be refreshed during the next stabilize
refreshCurrent() : Causes the current row to be refreshed on next stabilize
setColumn() : Replaces one TBColumn object with another
stabilize() : Performs incremental stabilization

TBColumn :

Provides the column objects TBrowse objects.

Description :

A TBColumn object is a simple object containing the information needed to fully define one data column of a TBrowse object (see the TBrowse reference in this chapter). TBColumn objects have no methods, only exported instance variables.

Class Function :

TBColumnNew() :

Create a new TBColumn object.

TBColumnNew(<cHeading>, <bBlock>) --> objTBColumn

Exported Instance Variables :

block : Code block to retrieve data for the column
cargo : User-definable variable
colorBlock : Code block that determines color of data items
colSep : Column separator character
defColor : Array of numeric indexes into the color table
footing : Column footing
footSep : Footing separator character
heading : Column heading
headSep : Heading separator character
width : Column display width

Example :

This example is a code fragment that creates a TBrowse object and adds some TBColumn objects to it:

USE Customer NEW
//
// Create a new TBrowse object
objBrowse := TBrowseDB(1, 1, 23, 79)
//
// Create some new TBColumn objects and
// add them to the TBrowse object
objBrowse:addColumn(TBColumnNew( "Customer", ;
                    {|| Customer->Name} ))
objBrowse:addColumn(TBColumnNew( "Address", ;
                    {|| Customer->Address} ))
objBrowse:addColumn(TBColumnNew( "City", ;
                    {|| Customer->City} ))
.
. <statements to actually browse the data>
.
CLOSE Customer

For a simple and working sample look at here.

Database Terms

Alias :

The name of a work area; an alternate name given to a database file. Aliases are often used to give database files descriptive names and are assigned when the database file is opened. If no alias is specified when the database file is USEd, the name of the database file becomes the alias.

An alias can be used to reference both fields and expressions (including user-defined functions). In order to alias an expression, the expression must be enclosed in parentheses.

See also : Work Area

Attribute :

As a formal DBMS term, refers to a column or field in a table or database file.

See Also: Column, Field

Beginning of File :

The top of the database file. In Clipper language there is no beginning of file area or record. Instead, it is indicated by BOF() returning true (.T.) if an attempt is made to move the record pointer above the first record in the database file or the database file is empty.

Cell :

In a table, a cell is the intersection of a Row and a Column.

Column :

A database term used to describe a field in a table or database file.

See Also: Field

Concurrency :

The degree to which data can be accessed by more than one user at the same time.

Condition :

A logical expression that determines whether an operation will take place. With database commands, a logical expression that determines what records are included in an operation. Conditions are specified as arguments of the FOR or WHILE clause.

See Also: Scope

Controlling/Master Index :

The index currently being used to refer to records by key value or sequential record movement commands.

See Also: Index, Natural Order

Database :

An aggregation of related operational data used by an application system. A database can contain one or more data files or tables.

See Also: Field, Record, Tuple, View

DBMS :

An acronym for the term database management system. A DBMS is a software system that mediates access to a database through a data manipulation language.

Delimited File :

A text file that contains variable-length database records with each record separated by a carriage return/linefeed pair (CHR(13) + CHR(10)) and terminated with an end of file mark (CHR(26)). Each field within a delimited file is variable length, not padded with either leading or trailing spaces, and separated by a comma. Character strings are optionally delimited to allow for embedded commas.

End of File :

The bottom of a database file. In Clipper language, this is LASTREC() + 1 and is indicated by EOF() returning true (.T.).

Field :

The basic column unit of a database file. A field has four attributes: name, type, length, and decimals if the type is numeric.

See Also: Database, Record, Tuple, Vector, View

Field Variable :

A variable that refers to data in a database field, as opposed to data in memory.

See Also: Local Variable, Memory Variable, Variable

Index :

An ordered set of key values that provides a logical ordering of the records in an associated database file. Each key in an index is associated with a particular record in the database file. The records can be processed sequentially in key order, and any record can be located by performing a SEEK operation with the associated key value.

See Also: Controlling/Master Index, Key Value, Natural Order

Join :

An operation that takes two tables as operands and produces one table as a result. It is, in fact, a combination of other operations including selection and projection.

See Also: Projection, Selection

Key Expression :

An expression, typically based on one or more database fields, that when evaluated, yields a key value for a database record. Key expressions are most often used to create indexes or for summarization operations.

See Also: Index, Key Value

Key Value :

The value produced by evaluating a key expression. When placed in an index, a key value identifies the logical position of the associated record in its database file.

See Also: Index, Key Expression

Master Index :

The index currently being used to refer to records by key value or sequential record movement commands.

See Also : Controlling/Master Index

Memo Type :

A special database field type consisting of one or more characters in the extended character set. The maximum size of a memo field In Clipper language is 65,534 bytes. A memo field differs only from a character string by the fact it is stored in a separate memo (.DBT file) and the field length is variable-length.

See Also: Character String

Natural Order :

For a database file, the order determined by the sequence in which records were originally entered into the file. Also called unindexed order.

See Also: Index

Normalization :

The process of elimination and consolidation of redundant data elements in a database system.

Projection :

A DBMS term specifying a subset of fields. In Clipper, the analogy is the FIELDS clause.

See Also: Join Selection

Query :

A request for information to be retrieved from a database. Alternately, a data structure in which such a request is encoded.

Record :

The basic row unit of a database file consisting of one or more field elements.

See Also: Database, Field, Table, Tuple

Relation :

A link between database files that allows the record pointer to move in more than one database file based on the value of a common field or expression. This allows information to be accessed from more than one database file at a time.

Relational Database System :

A system that stores data in rows and columns, without system dependencies within the data. In other words, relationships between different databases are not stored in the actual database itself, as is the case in a system that uses record pointers.

Row :

A group of related column or field values that are treated as a single entity. It is the same as a Clipper language record.

See Also: Column, Field, Record

Search Condition :

See : Condition, Scope

Scope :

In a database command, a clause that specifies a range of database records to be addressed by the command. The scope clause uses the qualifiers ALL, NEXT, RECORD, and REST to define the record scope.

See Also: Condition

SDF File :

A text file that contains fixed-length database records with each record separated by a carriage return/linefeed pair (CHR(13) + CHR(10)) and terminated with an end of file mark (CHR(26)). Each field within an SDF file is fixed-length with character strings padded with trailing spaces and numeric values padded with leading spaces. There are no field separators.

See Also: Database, Delimited File, Text File

Selection :

A DBMS term that specifies a subset of records meeting a condition. The selection itself is obtained with a selection operator. In Clipper language, the analogy is the FOR clause.

Separator :

The character or set of characters that differentiate fields or records from one another. In Clipper language, the DELIMITED and SDF file types have separators. The DELIMITED file uses a comma as the field separator and a carriage return/linefeed pair as the record separator. The SDF file type has no field separator, but also uses a carriage return/linefeed pair as the record separator.

See Also: Delimiter

Sort Order :

Describes the various ways database files and arrays are ordered.

. Ascending

Causes the order of data in a sort to be from lowest value to highest value.

. Descending

Causes the order of data in a sort to be from highest value to lowest value.

. Chronological

Causes data in a sort to be ordered based on a date value, from earliest to most recent.

. ASCII

Causes data in a sort to be ordered according to the ASCII Code values of the data to be sorted.

. Dictionary

The data in a sort is ordered in the way it would appear if the items sorted were entries in a dictionary of the English language.

. Collating Sequence

Data in a sort will be placed in sequence following the order of characters in the Extended Character Set.

. Natural

The order in which data was entered into the database.

Table :

A DBMS term defining a collection of column definitions and row values. In Clipper, it is represented and referred to as a database file.

Tuple :

A formal DBMS term that refers to a row in a table or a record in a database file. In DIF files, tuple also refers to the equivalent of a table record.

See Also: Database, Field, Record

Update :

The process of changing the value of fields in one or more records. Database fields are updated by various commands and the assignment operator.

Vector :

In a DIF file, vector refers to the equivalent of a table field.

See Also: Database, Field, Record, Tuple

View :

A DBMS term that defines a virtual table. A virtual table does not actually exist but is derived from existing tables and maintained as a definition. The definition in turn is maintained in a separate file or as an entry in a system dictionary file. In Clipper, views are supported only by DBU.EXE and are maintained in (.vew) files.

See Also: Database, Field, Record

Work Area :

The basic containment area of a database file and its associated indexes. Work areas can be referred to by alias name, number, or a letter designator.

See Also: Alias

User Interface Terms

Background Color :

The color that appears behind displayed text of another color (the foreground color).

See Also: Foreground Color

Column :

A numeric value that represents a position on the display screen or on the printed page.

Console Input/Output :

A style of operation of the keyboard and display that emulates a simple typewriter-like interface. Console input echoes each key typed and provides processing for the backspace and return keys. Console output wraps to the next line when the output reaches the right edge of the visible display, and scrolls the display when the output reaches the bottom of the visible display.

See Also: Full-screen Input/Output

Cursor :

An onscreen indicator used to show the current keyboard input focus and is displayed as a block or underline character. The cursor moves in response to characters or control keys typed by the user.

Enhanced Color :

The color used to display GETs or PROMPTs (if INTENSITY is ON).

See Also: Standard Color

Foreground Color :

The color of text appearing on the screen, usually on a different colored background.

See Also: Background Color

Full-screen Input/Output :

A style of operation of the keyboard and display used for complex data entry and display tasks. Full-screen input and output are generally performed using the @..SAY, @..GET and READ commands. Full-screen output is distinguished from console-style output by the fact that control characters (e.g., backspace, carriage return) are not processed, and wrapping and scrolling do not occur at the boundaries of the visible display area.

See Also: Console Input/Output

Highlight :

Indicates input focus for menus, browsers, or GETs. With menus and browsers, the currently selected item or cell has input focus and is displayed in the current enhanced color or inverse video. With GETs, the current GET is highlighted in the current enhanced color or inverse video while the other GETs are displayed in the current standard color if an unselected color setting is active.

See Also: Cell, Enhanced Color, Input Focus, Standard Color

Input Focus :

The GET, browse cell, or menu item where user interaction can take place is said to have input focus. The item with input focus usually is displayed in enhanced color or inverse video.

Insert Mode :

A data entry mode entered when the user presses the insert key. When this mode is active, characters are inserted at the cursor position. Text to the right of the cursor is shifted right.

See Also: Overstrike Mode

Keyboard Buffer :

An area of memory dedicated to storing input from the keyboard while a program is unable to process the input. When the program is able to accept the input, the keyboard buffer is emptied.

Menu :

An onscreen list of choices from which the user selects. Menus range from simple to elaborate forms. Two examples are menus that pull down from the top of the screen (an elaborate type requiring more programming), or a simple list of numbered items from which the user selects by entering the appropriate number.

Overstrike Mode :

A data entry mode entered when the user presses the insert key. When this mode is active, characters are entered at the cursor position and text to the right of the cursor remains stationary.

Picture :

A string that defines the format for data entry or display in a GET, SAY, or the return value of TRANSFORM(). Picture strings are comprised of functions which affect the formatting as a whole and a series of template characters that affect formatting on a character by character basis.

See Also: Template

Prompt :

A series of characters displayed on the screen indicating that input from the keyboard is expected.

Relative Addressing :

To refer to a memory address, array element, screen location, or printer location with respect to another value, rather than referring to a specific address or element.

Row :

A numeric expression that evaluates to an integer identifying a screen or printer row position.

See Also: Column, Field, Record

Scoreboard :

An area of the display on line 0 beginning at column 60 that displays status information during certain data entry operations.

Scrolling :

The action that takes place when the user attempts to move the cursor or highlight beyond the window boundary to access information not currently displayed.

See Also: Window

Standard Color :

The color pair definition that is used by all output options (such as SAY and ?), with the exception of GETs and PROMPTs, that use the enhanced color pair.

See Also : Enhanced Color

Template :

A mask that specifies the format in which data should be displayed. For example, you might want to store phone numbers as “9999999999” to save space, but use a template to display the number to the user as “(999) 999-9999.”

Typeahead Buffer :

See : Keyboard Buffer

Unselected Color :

The color pair definition used to display all but the current GET or the GET that has input focus. If this color setting is specified, the current GET is displayed using the current enhanced color.

See Also: Enhanced Color

User Function :

A user-defined function called by ACHOICE(), DBEDIT(), or MEMOEDIT() to handle key exceptions. A user function is supplied to one of these functions by passing a parameter consisting of a string containing the function’s name.

User Interface :

The way a program interacts with its user (i.e., menu operation and selection, data input methods, etc.)

Wait State :

A wait state is any mode that extracts keys from the keyboard except for INKEY(). These modes include ACHOICE(), DBEDIT(), MEMOEDIT(), ACCEPT, INPUT, READ and WAIT.

Window :

A rectangular screen region used for display. A window may be the same size or smaller than the physical screen. Attempting to display information that extends beyond the specified boundaries of the window clips the output at the window edge.

Word Wrapping :

The process of continuing the current text on the next line of a display when a boundary is reached and breaking the text on a word boundary.

Mini Agenda

This is a mini application developed primarily to denote some wonderful features of HMG.

Mini Agenda uses:

– A text (csv)  file for data source and Grid as browse of this file

– DEFINE ACTIVEX for “About” page from a .html file

– HFCL library ( Thanks to S. Rathinagiri for GridPrint )

Features :

– File operations: New, Open, ReOpen, Close, Save, Save as, Print

– Record operations:  Append, Delete, Insert

– Three way ( Natural, Ascending, Descending) sorting columns

– Preserve current item after sort

– In_place editing

– Incremental (and “soft” ) Search

– .ini File for keeping record of last used data file

Download : source, executable.