dbEdit()

Template

Function

Name

dbEdit()*

Category

API

Subcategory

User interface

Oneliner

Browse records in a table

Syntax

      dbEdit( [<nTop>],  [<nLeft>],  [<nBottom>],  [<nRight>],;  
              [<acColumns>], [<xUserFunc>], [<xColumnSayPictures>],;  
              [<xColumnHeaders>], [<xHeadingSeparators>], ; 
              [<xColumnSeparators>], [<xFootingSeparators>],;  
              [<xColumnFootings>] ) --> lOk

Arguments

<nTop> coordinate for top row display. <nTop> could range from 0 to MaxRow(), default is 0.

<nLeft> coordinate for left column display. <nLeft> could range from 0 to MaxCol(), default is 0.

<nBottom> coordinate for bottom row display. <nBottom> could range rom 0 to MaxRow(), default is MaxRow().

<nRight> coordinate for right column display. <nRight> could range from 0 to MaxCol(), default is MaxCol().

<acColumns> is an array of character expressions that contain database fields names or expressions to display in each column. If not specified, the default is to display all fields from the database in the current work area.

<xUserFunc> is a name of a user defined function or a code block
that would be called every time unrecognized key is been pressed or
when there are no keys waiting to be processed and dbEdit() goes
into idle mode. If <xUserFunc> is a character string, it must
contain root name of a valid user define function without
parentheses. Both the user define function or the code block should
accept two parameters: nMode, nCurrentColumn. Both should return
a numeric value that correspond to one of the expected return codes
(see table below for a list of nMode and return codes).

<xColumnSayPictures> is an optional picture. If <xColumnSayPictures>
is a character string, all columns would used this value as a
picture string. If <xColumnSayPictures> is an array, each element
should be a character string that correspond to a picture string
for the column with the same index. Look at the help for @…SAY
to get more information about picture values.

<xColumnHeaders> contain the header titles for each column, if this
is a character string, all columns would have that same header, if
this is an array, each element is a character string that contain
the header title for one column. Header may be split to more than
one line by placing semicolon (;) in places where you want to break
line. If omitted, the default value for each column header is taken
from <acColumns> or field name if <acColumns> was not specified.

<xHeadingSeparators> is an array that contain characters that draw
the lines separating the headers and the fields data. Instead of an
array you can use a character string that would be used to display
the same line for all fields. Default value is a double line.

<xColumnSeparators> is an array that contain characters that draw
the lines separating displayed columns. Instead of an array you can
use a character string that would be used to display the same line
for all fields. Default value is a single line.

<xFootingSeparators> is an array that contain characters that draw
the lines separating the fields data area and the footing area.
Instead of an array you can use a character string that would be
used to display the same line for all footers. Default is to have to
no footing separators.

<xColumnFootings> contain the footing to be displayed at the bottom
of each column, if this is a character string, all columns would
have that same footer, if this is an array, each element is a
character string that contain the footer for one column. Footer may
be split to more than one line by placing semicolon (;) in places
where you want to break line. If omitted, no footer are displayed.

Returns

dbEdit() return .F. if there is no database in use or if the number
of columns to display is zero, else dbEdit() return .T.

Description

dbEdit() display and edit records from one or more work areas in
a grid on screen. Each column is defined by element from <acColumns>
and is the equivalent of one field. Each row is equivalent of one
database record.

      Following are active keys that handled by dbEdit():       
      ---------------------------------------------------

      Key              Meaning

      Left             Move one column to the left (previous field)
      Right            Move one column to the right (next field)
      Up               Move up one row (previous record)
      Down             Move down one row (next record)
      Page-Up          Move to the previous screen
      Page-Down        Move to the next screen
      Ctrl Page-Up     Move to the top of the file
      Ctrl Page-Down   Move to the end of the file
      Home             Move to the leftmost visible column
      End              Move to the rightmost visible column
      Ctrl Left        Pan one column to the left
      Ctrl Right       Pan one column to the right
      Ctrl Home        Move to the leftmost column
      Ctrl End         Move to the rightmost column

When <xUserFunc> is omitted, two more keys are active:

      Key              Meaning

      Esc              Terminate Browse()
      Enter            Terminate Browse()

When dbEdit() execute <xUserFunc> it pass the following arguments:
nMode and the index of current record in <acColumns>. If <acColumns>
is omitted, the index number is the FIELD() number of the open
database structure.

      dbEdit() nMode could be one of the following:    
      ---------------------------------------------
      dbedit.ch      Meaning

      DE_IDLE        dbEdit() is idle,  all movement keys have been handled.
      DE_HITTOP      Attempt to cursor past top of file.
      DE_HITBOTTOM   Attempt to cursor past bottom of file.
      DE_EMPTY       No records in work area,  database is empty.
      DE_EXCEPT      Key exception.

The user define function or code block must return a value that tell
dbEdit() what to do next.

      
      User function return codes:    
      ---------------------------   

      dbedit.ch    Value   Meaning

      DE_ABORT     0       Abort dbEdit().
      DE_CONT      1       Continue dbEdit() as is.
      DE_REFRESH   2       Force reread/redisplay of all data rows.

The user function is called once in each of the following cases:
– The database is empty.
– The user try to move past top of file or past bottom file.
– Key exception, the uses had pressed a key that is not handled by dbEdit().
– The keyboard buffer is empty or a screen refresh had just occurred
dbEdit() is a compatibility function, it is superseded by the
TBrowse class and there for not recommended for new applications.

Examples

      // Browse a file using default values
      USE Test
      dbEdit()

Compliance

<xUserFunc> can take a code block value, this is a Harbour
extension.

CA-Cl*pper will throw an error if there’s no database open, Harbour
would return .F.

CA-Cl*pper is buggy and will throw an error if the number of columns
is zero, Harbour would return .F.

The CA-Cl*pper 5.2 NG state that the return value is NIL, this is
wrong and should be read logical.

There is an undocumented result code (3) from the user defined
function in CA-Cl*pper (both 87 and 5.x). This is an Append Mode which:
“split the screen to allow data to be appended in windowed area”.
This mode is not supported by Harbour.

Files

Header files are dbedit.ch, inkey.ch, Library is core

Seealso

@…SAY, Browse(), TBrowse class, Transform()