Title: Getting properties of components to your GUI and back.
Question: Getting your components to map your GUI so you don't have to type
Myobject.SomeString = Edit1.text;
Answer:
Dont u just hate it when u need to make a component Logic (so u can use it annywhere in COM, XML, DCOM, StandAlone-Apps and Internet (ISAPI/NSAPI) applications
In a StandAlone-App u wil have to map the data on to the gui and get it back (if editeble) without mapping everyting in sutch a olf fasion like this
Someobject.Somestring = Edit1.text ;
Someobject.Some1000stStringProperty = UntracebleEdit.text ;
just build all the logic in a class and wrap that with the aproperiat GUI
and take my routines here to do your dirty work.
in this example i added 1 RadioGroep with some items in its Items property
And its component name is exactly the same as the aExampleEnum property in the object.
i added a TCombobox and added some items to and set its Style property to csDropDownList and its name to AInteger
I added aTDateTimePicker and named it ADate and a Edit control with the name AString and a checkbox named Abool.
Now on two buttons i programd the call to the mapping recursion
note than u can use subobjects and call the Controls like this
SubobjectPropertyName_SomeProp
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ExtCtrls, ComCtrls;
type
TExampleEnum = (Enum1,Enum2,Enum3,Enum4,Enum5,Enum6,Enum7,Enum8,Enum9,Enum10);
TExampleComponent = Class(TComponent)
private
FAString: String;
FAFloat: Double;
FAInteger: Integer;
FaExampleEnum: TExampleEnum;
FaBool: Boolean;
FADate: tDatetime;
published
// Anyting you want streamed and is streameble by Delphi you can publish
// as property
Property AString : String read FAString write FAString;
Property AInteger : Integer read FAInteger write FAInteger;
Property AFloat : Double read FAFloat write FAFloat;
Property aExampleEnum : TExampleEnum read FaExampleEnum write FaExampleEnum;
Property aBool : Boolean read FaBool write FaBool;
Property ADate : tDatetime read FADate write FADate;
end;
TForm1 = class(TForm)
ObjectToGui: TButton;
GuiToObject: TButton;
aExampleEnum: TRadioGroup;
AInteger: TComboBox;
aBool: TCheckBox;
AFloat: TEdit;
ADate: TDateTimePicker;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure ObjectToGuiClick(Sender: TObject);
procedure GuiToObjectClick(Sender: TObject);
private
FExampleComponent: TExampleComponent;
procedure ControlsToPersist(APersistent: TPersistent;
AControl: TControl; Parentname: String);
procedure GetComponent(AComponent: TComponent;var aValue: Variant);
procedure PresistentToControls(APersistent: TPersistent;
AControl: TControl; ParentName: String);
procedure SetComponent(AComponent: TComponent; aValue: Variant);
{ Private declarations }
public
Property ExampleComponent : TExampleComponent read FExampleComponent write FExampleComponent;
{ Public declarations }
end;
var
Form1: TForm1;
implementation
uses typInfo ;
{$R *.DFM}
{ TForm1 }
procedure TForm1.PResistentToControls(APersistent: TPersistent;
AControl: TControl; ParentName : String );
var
PropList: PPropList;
PropCount : Integer ;
ClassTypeInfo: PTypeInfo;
ClassTypeData: PTypeData;
i : integer;
Propname : String;
aValue : Variant ;
AComponent : TComponent ;
begin
ClassTypeInfo := APersistent.ClassInfo ;
ClassTypeData := GetTypeData(ClassTypeInfo);
PropCount := ClassTypeData.PropCount -1 ;
// reserveer geheugen
GetMem(PropList, SizeOf(PPropInfo) * ClassTypeData.PropCount);
// Error trap
try
// Vul de prop list
GetPropList(APersistent.ClassInfo,tkAny,PropList);
for i := 0 to PropCount do
begin
try
Propname := Parentname + '_' + PropList[i]^.Name ;
If Propname[1] = '_'then Propname[1]:= ' ' ;
Propname := trim(Propname);
AComponent := AControl.FindComponent(Propname);
if AComponent nil then
begin
Case PropList[i]^.PropType^.Kind of
tkString,tkLString,
tkWString,tkWChar,
tkChar : begin
if (assigned(PropList[i]^.getProc)) then
aValue := GetStrProp(APersistent,PropList[i]) ;
end ;
tkInteger,
tkEnumeration: begin
aValue := GetOrdProp(APersistent,PropList[i]);
end;
tkFloat : begin
if (assigned(PropList[i]^.getProc)) then
if (PropList[i]^.PropType^.Name = 'TDateTime') then
begin
aValue := DateTimeToStr(GetFloatProp(APersistent,PropList[i]));
end else
begin
aValue := GetFloatProp(APersistent,PropList[i]) ;
end;
end;
end ;// end case
SetComponent(AComponent,aValue);
end;
if PropList[i]^.PropType^.Kind = tkClass then
begin
If GetObjectProp(APersistent,PropList[i]) is TPersistent then
begin
PResistentToControls(TPersistent(GetObjectProp(APersistent,PropList[i])),AControl,Propname);
end;
end;
Except
On e : Exception do
begin
// Handel error here
Showmessage(e.Message);
end;
end;
end; // for i := 0 to PropCount do
finally
FreeMem(PropList, SizeOf(PPropInfo) * ClassTypeData.PropCount);
end;
end;
procedure TForm1.SetComponent(AComponent: TComponent; aValue : Variant);
begin
If AComponent is TCustomEdit then
begin
TCustomEdit(AComponent).text := VarToStr(aValue);
// Onchange is a protected property of TCustomEdit so every one got it :)
If assigned(TEdit(AComponent).onchange) then
TEdit(AComponent).onchange(Self);
end else
If AComponent is TRadioGroup then
begin
TRadioGroup(AComponent).ItemIndex := StrTOInt(VarToStr(aValue)) ;
end else
If AComponent is TComboBox then
begin
If TComboBox(AComponent).Style = csDropDownList then
begin
If VarToStr(aValue) '' then
TComboBox(AComponent).ItemIndex := aValue ;
end
else
TComboBox(AComponent).text := VarToStr(aValue) ;
end
else
IF AComponent is TCheckBox then
begin
if VarToStr(aValue) = '1' then
TCheckBox(AComponent).Checked := True
else TCheckBox(AComponent).Checked := False ;
IF assigned(TCheckBox(AComponent).OnClick) then
TCheckBox(AComponent).OnClick(self);
end else
If AComponent is TDateTimePicker then
begin
If VarToStr(aValue) '' then
TDateTimePicker(AComponent).DateTime := VarToDateTime(aValue) ;
end
end;
procedure TForm1.ControlsToPersist(APersistent: TPersistent;
AControl: TControl ;Parentname : String );
var
PropList: PPropList;
PropCount : Integer ;
ClassTypeInfo: PTypeInfo;
ClassTypeData: PTypeData;
i : integer;
TempString : String ;
Propname : String;
Value : Variant ;
AComponent : TComponent ;
begin
ClassTypeInfo := APersistent.ClassInfo ;
ClassTypeData := GetTypeData(ClassTypeInfo);
PropCount := ClassTypeData.PropCount -1 ;
// Get mem for the list
GetMem(PropList, SizeOf(PPropInfo) * ClassTypeData.PropCount);
// Error trap
try
// Fill prop list
GetPropList(APersistent.ClassInfo,tkAny,PropList);
// For every property do
for i := 0 to PropCount do
begin
try
Propname := Parentname + '_' + PropList[i]^.Name ;
If Propname[1] = '_'then Propname[1]:= ' ' ;
Propname := trim(Propname);
AComponent := AControl.FindComponent(Propname);
IF AComponent nil then
begin
GetComponent(AComponent,Value);
Case PropList[i]^.PropType^.Kind of
tkString,tkLString,
tkWString,tkWChar,
tkChar : begin
if (assigned(PropList[i]^.SetProc)) then
begin
SetStrProp(APersistent,PropList[i], VarToStr(Value));
end;
end ;
tkInteger,
tkEnumeration: begin
Tempstring := VarToStr(Value) ;
If Tempstring '' then
begin
if (assigned(PropList[i]^.SetProc)) then
SetOrdProp(APersistent,PropList[i],StrToInt(Tempstring));
end;
end;
tkFloat : begin
IF VarToStr(Value) '' then
if (assigned(PropList[i]^.SetProc)) then
if (PropList[i]^.PropType^.Name = 'TDateTime') then
begin
SetFloatProp(APersistent,PropList[i],VarToDateTime(Value));
end else
begin
SetFloatProp(APersistent,PropList[i],StrTOFLoat(VarToStr(Value)));
end;
end;
end ;// end case
end;
// Alway do subojects even when there readonley.
if PropList[i]^.PropType^.Kind = tkClass then
begin
If GetObjectProp(APersistent,PropList[i]) is TPersistent then
begin
ControlsToPersist(TPersistent(GetObjectProp(APersistent,PropList[i])),AControl,Propname);
end;
end;
Except
On E: Exception do
begin
// Handel Errors here
Showmessage(e.Message);
end;
end ;
end; // end for i := 0 to PropCount
finally
FreeMem(PropList, SizeOf(PPropInfo) * ClassTypeData.PropCount);
end;
end;
procedure TForm1.GetComponent(AComponent: TComponent;var aValue : Variant );
begin
If AComponent is TCustomEdit then
begin
aValue := TCustomEdit(AComponent).text ;
end else
If AComponent is TRadioGroup then
begin
aValue := TRadioGroup(AComponent).ItemIndex ;
end else
If AComponent is TComboBox then
begin
If TComboBox(AComponent).Style = csDropDownList then
aValue := TComboBox(AComponent).ItemIndex
else
aValue := TComboBox(AComponent).text ;
end
else
IF AComponent is TCheckBox then
begin
if TCheckBox(AComponent).Checked then
aValue := 1 else
aValue := 0 ;
end else
IF AComponent is TDateTimePicker then
begin
aValue := VarFromDateTime(TDateTimePicker(AComponent).DateTime) ;
end ;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
FExampleComponent := TExampleComponent.Create(Self);
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
FExampleComponent.Free ;
end;
procedure TForm1.ObjectToGuiClick(Sender: TObject);
begin
PresistentToControls(FExampleComponent,Self,'');
end;
procedure TForm1.GuiToObjectClick(Sender: TObject);
begin
ControlsToPersist(FExampleComponent,Self,'');
end;
end.