clientdataset persistent fields property

[rbarone]

HI
if I connect a Tgrid to a Delphi 12.1 clientdataset, the grid is fed with all the persistent fields of the query
But if I act for example on the visible true/false property in the object inspector of persistent fields, this is not reflected on the Tgrid but I am forced to modify the Tgrid field by field to make what I want invisible or visible
Am I doing something wrong or is this how it works?

example problem

field_property.png (111.9 KiB) Viewed 107 times

[rbarone]

HI
I just discovered that to resolve this you need to unlink the clientdataset to the Tgrid with the object inspector, modify the persistent fields and then reconnect the clientdataset to the TGrid
This causes the components to lose some dynamism. Check how it behaves at runtime.
Maybe this could be an interesting fix?
Ciao

[Marc]

Hello,

Thanks for the follow-up, we'll take a look,

Regards,
Marc Meumann

[rbarone]

hi
still pertaining to the visible issue of persistent fields, I tried to make some code by adapting one of your examples to manage the expander
visible property at runtime doesn't work, the rest of the code works great
furthermore, changing the display label on the persistent field has no effect on the column title of the grid and this is a big problem, is there some instruction that I haven't found?
Help me please!
Am I doing something wrong?

/*********************************/
My_Ctgrid_class := C_TeeGrid_Class.Create;
// Initialize "Expander"
My_Ctgrid_class.max_col_footer := 4;

My_Ctgrid_class.Params_matrix[1].field_name := 'pk_progressivo';
My_Ctgrid_class.Params_matrix[1].position := 0;
My_Ctgrid_class.Params_matrix[1].type_function := 'count';

My_Ctgrid_class.Params_matrix[2].field_name := 'budget';
My_Ctgrid_class.Params_matrix[2].position := 5;
My_Ctgrid_class.Params_matrix[2].type_function := 'sum';

My_Ctgrid_class.Params_matrix[3].field_name := 'budget_utilizzato';
My_Ctgrid_class.Params_matrix[3].position := 6;
My_Ctgrid_class.Params_matrix[3].type_function := 'sum';

My_Ctgrid_class.Params_matrix[4].field_name := 'quota_detraibile';
My_Ctgrid_class.Params_matrix[4].position := 8;
My_Ctgrid_class.Params_matrix[4].type_function := 'average';

TeeGrid1 := My_Ctgrid_class.tgrid_expander(TeeGrid1, Cds_ListView, cds_detail, true, true);

(cds_detail is dataset in attach image)

/*********************************/



type
TParams = Record
field_name: string;
position: smallint;
type_function: string;
End;

C_TeeGrid_Class = class(TObject)

procedure CBEnabledChange(Sender: TObject);
private
{ Private declarations }
protected
public
{ Public declarations }
mydataset1_tmp, mydataset2_tmp: TclientDataSet;
Expander: TExpanderRender;
function tgrid_expander(mytgrid: tteegrid; mydataset1_in: TclientDataSet;
mydataset2_in: TclientDataSet; open_expander: boolean;
footer_calc: boolean): tteegrid;
procedure GetMyDati(const Sender: TExpanderRender; const ARow: Integer;
out AData: TObject);
function read_mydata(const ARecNo: Integer; mydataset1: TclientDataSet;
mydataset2: TclientDataSet): TclientDataSet;
function CloneData(const ADataSet: TclientDataSet): TclientDataSet;
// procedure DetailNewGroup(const Sender, NewGroup: TRowGroup; field_name1 :string; field_name2 : string);
procedure DetailNewGroup(const Sender, NewGroup: TRowGroup);

constructor Create;

var
max_col_footer: smallint;
Params_matrix: array [1 .. 10] of TParams;
{ I use the array to manage the totals row of the expander grid
I pass to the function the fields I want to be used, their position as columns and the type of
aggregation (this only at text level and then I manage with if se sum count etc)
}
end;

--------------------------
procedure C_TeeGrid_Class.CBEnabledChange(Sender: TObject);
begin
//
end;

// Return a new clone copy of ADataSet data, all rows
function C_TeeGrid_Class.CloneData(const ADataSet: TclientDataSet)
: TclientDataSet;
var
tmp: TMemoryStream;
begin
tmp := TMemoryStream.Create;
try
ADataSet.SaveToStream(tmp);
tmp.position := 0;

result := TclientDataSet.Create(nil);
TclientDataSet(result).LoadFromStream(tmp);
finally
tmp.Free;
end;

end;

procedure C_TeeGrid_Class.DetailNewGroup(const Sender, NewGroup: TRowGroup);
var
tmpTot: TColumnTotals;
i: smallint;
begin

// Create a Totals band
tmpTot := TColumnTotals.Create(NewGroup.Footer); // <--- set to Footer

// Add some calculations

for i := 1 to max_col_footer do
begin
if Params_matrix.type_function = 'count' then
begin
tmpTot.Calculation.Add(NewGroup.Columns[Params_matrix.position],
TColumnCalculation.Count);
tmpTot.Calculation.Add(Params_matrix.field_name,
TColumnCalculation.Count);
end;
if Params_matrix.type_function = 'sum' then
begin
tmpTot.Calculation.Add(NewGroup.Columns[Params_matrix.position],
TColumnCalculation.Sum);
tmpTot.Calculation.Add(Params_matrix.field_name,
TColumnCalculation.Sum);
end;
if Params_matrix.type_function = 'min' then
begin
tmpTot.Calculation.Add(NewGroup.Columns[Params_matrix.position],
TColumnCalculation.Min);
tmpTot.Calculation.Add(Params_matrix.field_name,
TColumnCalculation.Min);
end;
if Params_matrix.type_function = 'max' then
begin
tmpTot.Calculation.Add(NewGroup.Columns[Params_matrix[i].position],
TColumnCalculation.Max);
tmpTot.Calculation.Add(Params_matrix[i].field_name,
TColumnCalculation.Max);
end;
if Params_matrix[i].type_function = 'average' then
begin
tmpTot.Calculation.Add(NewGroup.Columns[Params_matrix[i].position],
TColumnCalculation.Average);
tmpTot.Calculation.Add(Params_matrix[i].field_name,
TColumnCalculation.Average);
end;
end;
// Add a Totals header:
TTotalsHeader.CreateTotals(NewGroup.Footer, tmpTot);

end;

procedure C_TeeGrid_Class.GetMyDati(const Sender: TExpanderRender;
const ARow: Integer; out AData: TObject);
begin

AData := TVirtualDBData.From(read_mydata(ARow + 1, mydataset1_tmp,
mydataset2_tmp));
end;

function C_TeeGrid_Class.read_mydata(const ARecNo: Integer;
mydataset1: TclientDataSet; mydataset2: TclientDataSet): TclientDataSet;
// Return the CustomerID for row: ARow
function key_ricerca: Integer;
begin
mydataset1.RecNo := ARecNo;
result := mydataset1.FieldByName('pk_progressivo').AsInteger;
end;

// Execute OrdersTable query for a given CustomerID
procedure FiltroDati(const key_ricerca: Integer);
begin
mydataset2.active := False;
mydataset2.ParamByName('pk_progressivo').AsInteger := key_ricerca;
mydataset2.active := True;
end;

begin
FiltroDati(key_ricerca);
result := CloneData(mydataset2);
end;

function C_TeeGrid_Class.tgrid_expander(mytgrid: tteegrid;
mydataset1_in: TclientDataSet; mydataset2_in: TclientDataSet;
open_expander: boolean; footer_calc: boolean): tteegrid;
begin
mydataset1_tmp := mydataset1_in;
mydataset2_tmp := mydataset2_in;

// Create "Expander"
Expander := mytgrid.grid.Current.NewExpander;

// Setup event
Expander.OnGetData := GetMyDati;

// We don't know in advance if a row can be expanded or not, so set Always
// Expander.AlwaysExpand := True;

// Set to first Column
mytgrid.Columns[0].Render := Expander;

// Optional:
if footer_calc = True then
mytgrid.grid.Current.OnNewDetail := DetailNewGroup;

if not open_expander then
Begin
mytgrid.grid.Current.ShowHideAllDetail(0, False);
Open := False;
End
else
Begin
mytgrid.grid.Current.ShowHideAllDetail(0, True);
Open := True;
End;

result := mytgrid;
end;

constructor C_TeeGrid_Class.Create;
begin
//
end;

end.

[Marc]

Hello,

We'll run some checks for suggestions.

Regards,
Marc Meumann

[Marc]

Hello,

The refreshing of the grid content should be done by modifying the source, as you observed in your earlier post. In addition to that your could modify the columns (hiding them) in relation to any particular fields that you may not wish to include at any time.

eg.

Code: Select all

  TeeGrid1.Columns.Items[3].Visible := not TeeGrid1.Columns.Items[3].Visible;
  TeeGrid1.Columns.Items[3].Header.Text := 'my col header text';

The best example, I think, that covers the use of expander is this one:

https://github.com/Steema/TeeGrid-VCL-F ... il_FireDAC

It is likely that you've seen it already. It includes methods to show/hide the expander and to implement it by code. Have you seen that code?

I'm sure this answer doesn't go into the detail you're looking for so please let us know what it's missing, I haven't been able to pick out all of the details from your code sample.

With thanks.
Regards,
Marc