Property editors

It is recommended to place property editors code in a separate file with Editor suffix. In our case, it was necessary to write editors for TfrxIBXDatabase.DatabaseName, TfrxIBXTable.IndexName, TfrxIBXTable.TableName properties. See more about writing properties editors in corresponding chapter. Below is example of such file:

unit frxIBXEditor;

interface
{$I frx.inc}

implementation

uses
  Windows, Classes, SysUtils, Forms, Dialogs, frxIBXComponents, frxCustomDB,
  frxDsgnIntf, frxRes, IBDatabase, IBTable
{$IFDEF Delphi6}
, Variants
{$ENDIF};

type
  TfrxDatabaseNameProperty = class(TfrxStringProperty)
  public
    function GetAttributes: TfrxPropertyAttributes; override;
    function Edit: Boolean; override;
  end;

  TfrxTableNameProperty = class(TfrxStringProperty)
  public
    function GetAttributes: TfrxPropertyAttributes; override;
    procedure GetValues; override;
  end;

  TfrxIndexNameProperty = class(TfrxStringProperty)
  public
    function GetAttributes: TfrxPropertyAttributes; override;
    procedure GetValues; override;
  end;

{ TfrxDatabaseNameProperty }
function TfrxDatabaseNameProperty.GetAttributes: TfrxPropertyAttributes;
begin
  { this property possesses  editor }
  Result := [paDialog];
end;

function TfrxDatabaseNameProperty.Edit: Boolean;
var
  SaveConnected: Bool;
  db: TIBDatabase;
begin
  { get link to TfrxIBXDatabase.Database }
  db := TfrxIBXDatabase(Component).Database;
  { create standard OpenDialog }
  with TOpenDialog.Create(nil) do
  begin
    InitialDir := GetCurrentDir;
    { we are interested in *.gdb files }
    Filter := frxResources.Get('ftDB') + ' (*.gdb)|*.gdb|' + frxResources.Get('ftAllFiles') + ' (*.*)|*.*';
    Result := Execute;
    if Result then
    begin
      SaveConnected := db.Connected;
      db.Connected := False;
      { if dialogue is completed successfully, assign new DB name }
      db.DatabaseName := FileName;
      db.Connected := SaveConnected;
    end;
    Free;
  end;
end;

{ TfrxTableNameProperty }
function TfrxTableNameProperty.GetAttributes: TfrxPropertyAttributes;
begin
  {  property represents list of values }
  Result := [paMultiSelect, paValueList];
end;

procedure TfrxTableNameProperty.GetValues;
var
  t: TIBTable;
begin
  inherited;
  { get link to  TIBTable  component }
  t := TfrxIBXTable(Component).Table;
  { fill list of tables available }
  if t.Database <> nil then
    t.DataBase.GetTableNames(Values, False);
end;

{ TfrxIndexProperty }
function TfrxIndexNameProperty.GetAttributes: TfrxPropertyAttributes;
begin
  {  property represents list of values }
  Result := [paMultiSelect, paValueList];
end;

procedure TfrxIndexNameProperty.GetValues;
var
  i: Integer;
begin
  inherited;
  try
    { get link to TIBTable component }
    with TfrxIBXTable(Component).Table do
      if (TableName <> '') and (IndexDefs <> nil) then
      begin
        { update indexes }
        IndexDefs.Update;
        { fill list of indexes available }
        for i := 0 to IndexDefs.Count - 1 do
          if IndexDefs[i].Name <> '' then
            Values.Add(IndexDefs[i].Name);
      end;
  except
  end;
end;

initialization
  frxPropertyEditors.Register(TypeInfo(String), TfrxIBXDataBase, 'DatabaseName', TfrxDataBaseNameProperty);
  frxPropertyEditors.Register(TypeInfo(String), TfrxIBXTable, 'TableName', TfrxTableNameProperty);
  frxPropertyEditors.Register(TypeInfo(String), TfrxIBXTable, 'IndexName', TfrxIndexNameProperty);
end.