<< Click to Display Table of Contents >> Navigation:  Programming > Mail Merge (replace fields with data) and data forms > Forms & Edit Fields (data forms) > Read and Write Data

Edit fields can be read out using procedure MailMerge and event OnMailMergeGetText:

 

// Read the data which is currently displayed in the editor

procedure TWPEdTest.ReadData;

begin

  FReadingData := TRUE; // global boolean to change behaviour

  DataEdit.MergeText;

end;

 

// Write back the data

procedure TWPEdTest.WriteData;

begin

  FReadingData := FALSE;

  DataEdit.MergeText;

end;

 

// This reads and writes the data fro the database 'Table1'

procedure TWPEdTest.DataEditMailMergeGetText(Sender: TObject;

const inspname: String; Contents: TWPMMInsertTextContents);

begin

    if FReadingData then

          Table1.FieldByName(inspname).AsString := Contents.OldText

    else  Contents.StringValue := Table1.FieldByName(inspname).AsString;

end;

end;

 

The code above automatically deals with checkbox fields since the TWPMMInsertTextContents detects if there is a FORMCHECKBOX field inside of the merge field and updates its "Params" property automatically.  If the field is empty, the logic has no way to detect that a checkbox is required to display the value of a field. You can use the option  mmHandleFORMCHECKBOX to fix this, a checkbox will be automatically created. Of course it is also possible to remove the flag to disable the automatic object handling.

 

if Table1.FieldByName(inspname) is TBooleanField then

    Contents.Options := Contents.Options + [mmHandleFORMCHECKBOX];

 

If you rather update the field in your code, you can use Contents.SetBoolean(b, wpcvFormCheckbox) instead of updating the Contents.StringValue.