MOL (Marek Olszewski)

Contributed samples by MOL (Marek Olszewski)

Backup-Restore

Billing System ( definable buttons )

Calculator

Copy To Clipboard

Deactivate menu

Debug Message

Download from www

EAN13 BarCode Generator

Filter in Browse

HMG with MS SQL server

Incremental Search in BROWSE 

Menu like ACHOICE

Moldruk (Print like DOS )

Set Status Bar Item

Send mails via SMTP

Using ProgressBar as a graph

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SAVE

SAVE

Save variables to a memory (.mem) file

Syntax

      SAVE TO <xcMemFile> [ALL [LIKE | EXCEPT <skeleton>]]

Arguments

<xcMemFile> is the memory (.mem) file to SAVE to disk. You may specify the file name as a literal string or as a character expression enclosed in parentheses. If you specify no extension, the file is created with a .mem extension.

ALL [LIKE|EXCEPT <skeleton>] defines the set of visible private and public memory variables to save to <xcMemFile>. <skeleton> is the wildcard mask that characterizes a group of memory variables to SAVE. The wildcard characters supported are * and ?.

Description

SAVE copies public and private memory variables visible within the current procedure or user-defined function to a memory (.mem) file. Arrays and local and static variables, however, cannot be SAVEd. When variables are SAVEd, they are copied without any reference to scope. Variables hidden by PRIVATE or LOCAL declarations are not SAVEd.

If you specify the ALL LIKE clause, variable names matching the <skeleton> mask are saved. By contrast, if you specify ALL EXCEPT, variable names not matching the <skeleton> are saved.

You can specify a <skeleton> that includes wildcard characters. The * wildcard character matches any group of adjacent characters ending a variable name and can be specified only at the end of the <skeleton>. The ? wildcard character matches any single character and can be specified anywhere within the <skeleton>.

Examples

      .  This example saves all visible private and public variables to
         Temp.mem:

         PRIVATE cOne := "1"
         SAVE ALL TO Temp

      .  This example saves all visible private and public variables
         with names beginning with "c" to Myvars.mem:

         SAVE ALL LIKE c* TO MyVars

      .  This example saves all visible private and public variables
         with names that do not begin with "c" to Myvars2.mem:

         SAVE ALL EXCEPT c* TO MyVars2

Seealso

LOCAL, PRIVATE, PUBLIC, RESTORE

C5_RESTORE

 RESTORE
 Retrieve memory variables from a memory (.mem) file
------------------------------------------------------------------------------
 Syntax

     RESTORE FROM <xcMemFile> [ADDITIVE]

 Arguments

     <xcMemFile> is the memory (.mem) file to load from disk.  If an
     extension is not specified, the extension .mem is assumed.  The file
     name may be specified as a literal string or as a character expression
     enclosed in parentheses.

     ADDITIVE causes memory variables loaded from the memory file to be
     added to the existing pool of memory variables.

 Description

     RESTORE is a memory variable command that recreates public and private
     variables previously SAVEd to a memory (.mem) file and initializes them
     with their former values.  The scope of the variable is not SAVEd with
     the variable, but is instead established when the variable is RESTOREd.
     Arrays and local variables cannot be SAVEd or RESTOREd.

     When memory variables are RESTOREd, they are recreated as private
     variables with the scope of the current procedure or user-defined
     function unless they exist as public variables and you specify the
     ADDITIVE clause.  If ADDITIVE is specified, public and private variables
     with the same names are overwritten unless hidden with PRIVATE.  If
     ADDITIVE is not specified, all public and private variables are released
     before the memory file is loaded.

     Local and static variables are unaffected by RESTORE.  If a local or
     static variable has been declared in the current procedure or user-
     defined function and a variable with the same name is RESTOREd, only the
     local or static variable is visible unless references to the RESTOREd
     variable are prefaced with the MEMVAR alias.

 Examples

     .  This example demonstrates a typical application of SAVE and
        RESTORE.  Here memory variables containing screens are SAVEd TO and
        RESTOREd FROM memory files:

        // Create and use a pseudoarray of screens
        SAVE SCREEN TO cScreen1
        SAVE ALL LIKE cScreen* TO Screens
        //
        <statements>...
        //
        RESTORE FROM Screens ADDITIVE
        nNumber = "1"
        RESTORE SCREEN FROM ("cScreen" + nNumber)

 Files   Library is CLIPPER.LIB.

See Also: LOCAL PRIVATE PUBLIC SAVE

 

C5 Commands

 ?|??            Display one or more values to the console
 @...BOX         Draw a box on the screen
 @...CLEAR       Clear a rectangular region of the screen
 @...GET         Create a new Get object and display it
 @...PROMPT      Paint a menu item and define a message
 @...SAY         Display data at a specified screen or printer row and column
 @...TO          Draw a single- or double-line box
 ACCEPT*         Place keyboard input into a memory variable
 APPEND BLANK    Add a new record to the current database file
 APPEND FROM     Import records from a database (.dbf) file or ASCII text file
 AVERAGE         Average numeric expressions in the current work area
 CALL*           Execute a C or Assembler procedure
 CANCEL*         Terminate program processing
 CLEAR ALL*      Close files and release public and private variables
 CLEAR GETS      Release Get objects from the current GetList array
 CLEAR MEMORY    Release all public and private variables
 CLEAR SCREEN    Clear the screen and return the cursor home
 CLEAR TYPEAHEAD Empty the keyboard buffer
 CLOSE           Close a specific set of files
 COMMIT          Perform a solid-disk write for all active work areas
 CONTINUE        Resume a pending LOCATE
 COPY FILE       Copy a file to a new file or to a device
 COPY STRUCTURE  Copy the current .dbf structure to a new database (.dbf) file
 COPY STRU EXTE  Copy field definitions to a .dbf file
 COPY TO         Export records to a database (.dbf) file or ASCII text file
 COUNT           Tally records to a variable
 CREATE          Create an empty structure extended (.dbf) file
 CREATE FROM     Create a new .dbf file from a structure extended file
 DELETE          Mark records for deletion
 DELETE FILE     Remove a file from disk
 DELETE TAG      Delete a tag
 DIR*            Display a listing of files from a specified path
 DISPLAY         Display records to the console
 EJECT           Advance the printhead to top of form
 ERASE           Remove a file from disk
 FIND*           Search an index for a specified key value
 GO              Move the pointer to the specified identity
 INDEX           Create an index file
 INPUT*          Enter the result of an expression into a variable
 JOIN            Create a new database file by merging from two work areas
 KEYBOARD        Stuff a string into the keyboard buffer
 LABEL FORM      Display labels to the console
 LIST            List records to the console
 LOCATE          Search sequentially for a record matching a condition
 MENU TO         Execute a lightbar menu for defined PROMPTs
 NOTE*           Place a single-line comment in a program file
 PACK            Remove deleted records from a database file
 QUIT            Terminate program processing
 READ            Activate full-screen editing mode using Get objects
 RECALL          Restore records marked for deletion
 REINDEX         Rebuild open indexes in the current work area
 RELEASE         Delete public and private memory variables
 RENAME          Change the name of a file
 REPLACE         Assign new values to field variables
 REPORT FORM     Display a report to the console
 RESTORE         Retrieve memory variables from a memory (.mem) file
 RESTORE SCREEN* Display a saved screen
 RUN             Execute a DOS command or program
 SAVE            Save variables to a memory (.mem) file
 SAVE SCREEN*    Save the current screen to a buffer or variable
 SEEK            Search an order for a specified key value
 SELECT          Change the current work area
 SET ALTERNATE   Echo console output to a text file
 SET BELL        Toggle sounding of the bell during full-screen operations
 SET CENTURY     Modify the date format to include or omit century digits
 SET COLOR*      Define screen colors
 SET CONFIRM     Toggle required exit key to terminate GETs
 SET CONSOLE     Toggle console display to the screen
 SET CURSOR      Toggle the screen cursor on or off
 SET DATE        Set the date format for input and display
 SET DECIMALS    Set the number of decimal places to be displayed
 SET DEFAULT     Set the CA-Clipper default drive and directory
 SET DELETED     Toggle filtering of deleted records
 SET DELIMITERS  Toggle or define GET delimiters
 SET DESCENDING  Change the descending flag of the controlling order
 SET DEVICE      Direct @...SAYs to the screen or printer
 SET EPOCH       Control the interpretation of dates with no century digits
 SET ESCAPE      Toggle Esc as a READ exit key
 SET EXACT*      Toggle exact matches for character strings
 SET EXCLUSIVE*  Establish shared or exclusive USE of database files
 SET FILTER      Hide records not meeting a condition
 SET FIXED       Toggle fixing of the number of decimal digits displayed
 SET FORMAT*     Activate a format when READ is executed
 SET FUNCTION    Assign a character string to a function key
 SET INDEX       Open one or more order bags in the current work area
 SET INTENSITY   Toggle enhanced display of GETs and PROMPTs
 SET KEY         Assign a procedure invocation to a key
 SET MARGIN      Set the page offset for all printed output
 SET MEMOBLOCK   Change the block size for memo files
 SET MESSAGE     Set the @...PROMPT message line row
 SET OPTIMIZE    Change the setting that optimizes using open orders
 SET ORDER       Select the controlling order
 SET PATH        Specify the CA-Clipper search path for opening files
 SET PRINTER     Toggle echo of output to printer or set the print destination
 SET PROCEDURE*  Compile procedures and functions into the current object file
 SET RELATION    Relate two work areas by a key value or record number
 SET SCOPE       Change the boundaries for scoping keys in controlling order
 SET SCOPEBOTTOM Change bottom boundary for scoping keys in controlling order
 SET SCOPETOP    Change top boundary for scoping keys in controlling order
 SET SCOREBOARD  Toggle the message display from READ or MEMOEDIT()
 SET SOFTSEEK    Toggle relative seeking
 SET TYPEAHEAD   Set the size of the keyboard buffer
 SET UNIQUE*     Toggle inclusion of non-unique keys into an index
 SET WRAP*       Toggle wrapping of the highlight in menus
 SKIP            Move the record pointer to a new position
 SORT            Copy to a database (.dbf) file in sorted order
 STORE*          Assign a value to one or more variables
 SUM             Sum numeric expressions and assign results to variables
 TEXT*           Display a literal block of text
 TOTAL           Summarize records by key value to a database (.dbf) file
 TYPE            Display the contents of a text file
 UNLOCK          Release file/record locks set by the current user
 UPDATE          Update current database file from another database file
 USE             Open an existing database (.dbf) and its associated files
 WAIT*           Suspend program processing until a key is pressed
 ZAP             Remove all records from the current database file

 

The Art Of Simplicity

A discussion of how to create objects with Clipper using arrays, and ordinary Clipper syntax. Has several good examples.

An Introduction into Object Oriented Programming.

To me, the challenge of programming is in finding a simple clean way to implement a program. Making sure no matter how complex the specs are, the code itself stays small, strait forward, and easy to maintain.

To illustrate how to reduce the complexity of things, lets examine the box drawing routines. Normally to display a nondestructive box on the screen you write something like this:

 old_row:=row()
 old_col:=col()
 old_cursor:=setcursor()
 old_screen:=savescreen(10, 20, 16, 59)
 old_color:=setcolor("w+/n, w+/r")
 @ 10, 20, 16, 59 BOX 'ÚÄ¿³ÙÄÀ³ '

Then when you are done and wish to remove the box, you reverse the procedure:

 restscreen(10,20,16,59,old_screen)
 setcolor(old_color)
 setcursor(old_cursor)
 setpos(old_row,old_col)

This scheme results in using 9 lines of code, 5 memory variables, and requires that the programmer maintain the box coordinates in 3 different places. After going through this procedure a few times I started wondering if there was a better way of doing this.

When I tried to solve this problem, I had several false starts. I created a procedure to display the box that saved all the variables to statics, and the next time it was called it would restore the box. That didn’t work too well since I often wanted more than a single box on the screen.

Then I tried saving the memvars to an array that I used like a stack. But that didn’t work out too well either, since it required that all boxes be removed in the same order that they were created.

Then I decided that all the memvars being used to store the box information belonged in the calling routine, where they had been all along. Despite the fact that this seemed to bring me back to square one I continued with this train of thought.

If I stored all the memvars being used by the box routine in an array, then all the memvars could be stored in a single package, and passed to the calling routine without complications:

aBox := CreateBox(10, 20, 16, 59, "w+/n, w+/r")

And when I no longer needed the box and wished to restore the original screen:

DestroyBox( aBox )

Please compile DEMO1, to see the basic box functions.

CreateBox() and DestroyBox() are used to replace 10 lines of code, and the array aBox was used to replace 5 variables. Putting all the data into the array aBox and handling only the array, makes things much simpler.

Now that we have developed this technique, we could theoretically create a number functions that work together, like CreateBox() and DestroyBox(), and use the data contained in aBox. And in the file BOX.PRG, I have a group of sample functions that do just that:

 CreateBox()
 DestroyBox()
 BoldBox()
 MoveBox()

Another benefit of this technique, is that we can have multiple arrays that each correspond to separate boxes, and use them all at the same time.

For example, we could write a program with a couple of boxes:

 aBox1 := CreateBox( 05,  26,  20,  53,  "w+/n, w+/n" )
 aBox2 := CreateBox( 10,  20,  16,  59,  "w+/b, w+/b" )

To move the second box:

MoveBox( aBox2,  -08,  -18 )

Then we could give the second box a highlight:

BoldBox( aBox2, "w+/b, w+/b" )

Then to remove both boxes:

 DestroyBox(aBox2)
 DestroyBox(aBox1)

This example does some fairly complex things, and it does so, in only six lines of code. To run this example, compile the file DEMO2.PRG.

This programming technique has a name, it is called Object Oriented Programing (OOP).

According to OOP terminology the arrays aBox1 and aBox2 are objects, and the functions CreateBox, MoveBox, BoldBox, and DestroyBox are methods.

Objects are collections of related data, or in dBase terminology, arrays of related memvars. In our example, aBox1 and aBox2 are qualify as objects since they contain related data (the coordinates of the box, the original color, cursor position, cursor status, etc.).

In object oriented programming, several instances of an object can be created, and later destroyed when we are finished with them. In our example, aBox1 and aBox2, constitute two separate instances of box objects.

If you look at the example in DEMO3.PRG, you will see that the program creates an array of four box objects, and four separate instances of the box object are on the screen at once.

A methods is a special type of function. Methods are functions that are grouped together, and manipulate the same data objects. In the file BOX.PRG, you will see the code for four methods that use the box objects ( CreateBox, DestroyBox, BoldBox, MoveBox )

CreateBox is a special type of method called a constructor, because it creates a box object and initializes it.

DestroyBox is a special type of method called a destructor, because it destroys a box object and frees of the memory that the box object used.

Every time we call a method / function, we pass it the object we want the method to manipulate. In our example, we have two objects, aBox1 and aBox2. To move the first box, we called the method MoveBox() like this:

MoveBox( aBox1, 1, 1 )

And to bold the second box, we called the method BoldBox() like this:

BoldBox( aBox2, "w+/b,w+/n" )

The constructor CreateBox doesn’t need to be passed the object, because the constructor creates the object.

Now that you understand what an object is, you can create additional functions / methods that use the box object. And hopefully go on to create your own objects and methods.

Cynthia Allingham, 1991

/***
*
* BOX.PRG
*
* Written By: Cynthia Allingham 11/01/91
* Purpose: Displays exploding box on the screen
* Returns: Previous screen contents
*/
FUNC CreateBox (nTop, nLeft, nBottom, nRight, box_color)
local save_window:=savescreen(nTop, nLeft, nBottom, nRight)
local save_color:=setcolor(box_color)
local save_cursor:=setcursor()
local save_row:=row()
local save_column:=col()
@ nTop,nLeft,nBottom,nRight BOX 'ÚÄ¿³ÙÄÀ³ '
RETURN {nTop, nLeft, nBottom, nRight, save_window,;
 save_color, save_cursor, save_row, save_column}
/***
* Written By: Cynthia Allingham 11/01/91
* Purpose: destroys the box and restores old settings
*/
FUNC DestroyBox (aList)
restscreen(aList[1],aList[2],aList[3],aList[4],aList[5])
setcolor(aList[6])
setcursor(aList[7])
setpos(aList[8],aList[9])
aList:=nil
return nil
/***
* Written By: Cynthia Allingham 11/01/91
* Purpose: Changes the box border
*/
FUNC BoldBox (aList, cColor)
@ aList[1],aList[2],aList[3],aList[4];
 BOX 'ÛßÛÛÛÜÛÛ' color cColor
return nil
/***
* Written By: Cynthia Allingham 11/01/91
* Purpose: Redimensions the screen
*/
FUNC MoveBox (aList, nVert, nHorz)
local save_window:=savescreen(aList[1],aList[2],aList[3],aList[4])
dispbegin()
restscreen(aList[1],aList[2],aList[3],aList[4],aList[5])
aList[3] += nVert; aList[1]+=nVert
aList[4] += nHorz; aList[2]+=nHorz
aList[5]:=savescreen(aList[1],aList[2],aList[3],aList[4])
restscreen(aList[1],aList[2],aList[3],aList[4],save_window)
dispend()
return nil
* EOF BOX.PRG
/***
*
* DEMO1.PRG
*
* Written By: Cynthia Allingham 11/01/91
* Purpose: Simple program demonstrating the creation and
* destruction of a box object.
*/
local aBox
set procedure to box
@ 00,00,24,79 box 'ÚÄ¿³ÙÄÀ³°'
aBox:=CreateBox(10, 20, 16, 59, "w+/n, w+/r")
@22,19 say padc("Press any key to destroy the box",40)
inkey(10)
DestroyBox(aBox)
* EOF DEMO1.PRG
/***
*
* DEMO2.PRG
*
* Written By: Cynthia Allingham 11/01/91
* Purpose: Demonstates the use of two box objects
*/
local aBox1, aBox2
set procedure to box
@ 00,00,24,79 box 'ÚÄ¿³ÙÄÀ³°'
aBox1:=CreateBox(05, 26, 20, 53, "w+/n, w+/n")
message("Press any key to create a second box")
aBox2:=CreateBox(10, 20, 16, 59, "w+/b, w+/b")
message("Press any key to move the second box")
MoveBox(aBox2, -08, -18)
message ("Press any key to bold the second box")
BoldBox(aBox2, "w+/b, w+/b")
message("Press any key to destroy both boxes")
DestroyBox(aBox2)
DestroyBox(aBox1)
func message(ctext)
@22,19 say padc(ctext,40)
inkey(10)
* EOF DEMO2.PRG
/***
*
* DEMO3.PRG
*
* Written By: Cynthia Allingham 11/01/91
* Purpose: Demonstates the use of four box objects
*/
local aBox[4]
local cnt
set procedure to box
@ 00,00,24,79 box 'ÚÄ¿³ÙÄÀ³°'
aBox[1]:=CreateBox(05, 05, 09, 30, "w+/n, w+/n")
@ 06, 07 say "box #1"
aBox[2]:=CreateBox(18, 03, 22, 14, "w+/b, w+/b")
@ 20, 05 say "box #2"
aBox[3]:=CreateBox(20, 48, 22, 77, "w+/r, w+/r")
@ 21, 50 say "box #3"
aBox[4]:=CreateBox(02, 64, 12, 75, "w+/gr, w+/gr")
@ 03, 66 say "box #4"
for cnt:=1 to 12
 inkey(0.5)
 MoveBox(aBox[1], +1, 0)
 MoveBox(aBox[2], 0,+4)
 MoveBox(aBox[3], -1, 0)
 MoveBox(aBox[4], 0,-4)
next
inkey(10)
for cnt:=1 to 4
 DestroyBox(aBox[cnt])
next
* EOF DEMO3.PRG

C5 Variable Handling Commands

ACCEPT :

Place keyboard input into a memory variable

ACCEPT [<expPrompt>] TO <idVar>

CLEAR ALL* :

Close files and release public and private variables

CLEAR ALL

CLEAR MEMORY :

Release all public and private variables

CLEAR MEMORY

DECLARE* :

Create and initialize private memory variables and arrays

DECLARE <identifier> [[:= <initializer>], ... ]

FIELD :

Declare database field names

FIELD <idField list> [IN <idAlias>]

INPUT :

Enter the result of an expression into a variable

INPUT [<expPrompt>] TO <idVar>

LOCAL :

Declare and initialize local variables and arrays

LOCAL <identifier> [[:= <initializer>], ... ]

MEMVAR :

Declare private and public variable names

MEMVAR <idMemvar list>

MEMVARBLOCK() :

Return a set-get code block for a given memory variable

MEMVARBLOCK(<cMemvarName>) --> bMemvarBlock

PARAMETERS :

Create private parameter variables

PARAMETERS <idPrivate list>

PRIVATE :

Create and initialize private memory variables and arrays

PRIVATE <identifier> [[:= <initializer>], ... ]

PUBLIC :

Create and initialize public memory variables and arrays

PUBLIC <identifier> [[:= <initializer>], ... ]

RELEASE :

Delete public and private memory variables

RELEASE <idMemvar list>
RELEASE ALL [LIKE | EXCEPT <skeleton>]

RESTORE :

Retrieve memory variables from a memory (.mem) file

RESTORE FROM <xcMemFile> [ADDITIVE]

SAVE :

Save variables to a memory (.mem) file

SAVE TO <xcMemFile> [ALL [LIKE | EXCEPT <skeleton>]]

STATIC :

Declare and initialize static variables and arrays

STATIC <identifier> [[:= <initializer>], ... ]

STORE* :

Assign a value to one or more variables

STORE <exp> TO <idVar list>
<idVar> = <exp>
<idVar> := [ <idVar2> := ...] <exp>