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Saving data from a list in XML?

I have 2 lists, the first list stores data pointers for each object. Property Object (defined by a special class that I wrote). Whenever I select an item from this list, I fill out the second list, accessing some data stored in the first list.

This is good, but now I need to know how to save and restore lists in XML.

I would appreciate it if someone could give an example or help me write code to do this.

Here is a sample code to show how I create and access data:

unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls; type TForm1 = class(TForm) ListBox1: TListBox; ListBox2: TListBox; cmdAdd: TButton; txtValue1: TEdit; txtValue2: TEdit; procedure cmdAddClick(Sender: TObject); procedure ListBox1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; type TMyData = class(TObject) private FValue1: String; FValue2: String; public constructor Create(Value1, Value2: String); property Value1: String read FValue1 write FValue1; property Value2: String read FValue2 write FValue2; end; var Form1: TForm1; implementation {$R *.dfm} { TMyData } constructor TMyData.Create(Value1, Value2: String); begin inherited Create; FValue1:= Value1; FValue2:= Value2; end; procedure TForm1.cmdAddClick(Sender: TObject); var Obj: TMyData; begin Obj:= TMyData.Create(txtValue1.Text, txtValue2.Text); Listbox1.AddItem(txtValue1.Text, Obj); end; procedure TForm1.ListBox1Click(Sender: TObject); var Obj: TMyData; begin ListBox2.Items.Clear; Obj:= ListBox1.Items.Objects[ListBox1.ItemIndex] as TMyData; ListBox2.Items.Add(Obj.Value2); end; end.
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tl; dr: Use the XML Data Binding Wizard to create interfaces for processing your specific XML file, Êt voila.

The easiest way to implement this is to start with an XML file. For example, create it as follows:

 <?xml version="1.0"?> <masteritems> <masteritem> <name>Caption1</name> <value>123456</value> <childitems> <childitem> <name>Caption1.1</name> <value>23452</value> </childitem> <childitem> <name>Caption1.2</name> <value>65465</value> </childitem> </childitems> </masteritem> <masteritem> ... </masteritem> </masteritems>

Then create an interface module for this type of XML file using the XML Data Binding Wizard , see File> New> Other> New> XML Data Binding. Adjust as you like, but just pass each page of the wizard by clicking OK, it works fine by default. (Note that the default settings for other versions of Delphi may differ from the default settings.) Although the only thing I personally need to get rid of is the Type suffix for each type of interface. (As well as for class type names, but this is not an option in the wizard, so you can do it manually.)

And now, to download and process this XML file:

 uses Classes, Controls, Forms, StdCtrls, Test, xmldom, XMLIntf, msxmldom, XMLDoc; type TForm2 = class(TForm) ListBox1: TListBox; ListBox2: TListBox; XMLDocument1: TXMLDocument; { See tab 'Internet' on component palette } SaveButton: TButton; procedure FormCreate(Sender: TObject); procedure ListBox1Click(Sender: TObject); procedure SaveButtonClick(Sender: TObject); private function CurrentMasterItem: IXMLMasterItem; end; ... function TForm2.CurrentMasterItem: IXMLMasterItem; var MasterItems: IXMLMasterItems; I: Integer; begin MasterItems := GetMasterItems(XMLDocument1); for I := 0 to MasterItems.Count - 1 do begin Result := MasterItems.Masteritem[I]; if Result.Name = ListBox1.Items[ListBox1.ItemIndex] then Break; end; end; procedure TForm2.FormCreate(Sender: TObject); var MasterItems: IXMLMasterItems; I: Integer; begin XMLDocument1.FileName := 'Test.xml'; XMLDocument1.NodeIndentStr := '<tab>'; MasterItems := GetMasterItems(XMLDocument1); for I := 0 to MasterItems.Count - 1 do ListBox1.Items.Add(MasterItems[I].Name); XMLDocument1.Active := False; end; procedure TForm2.ListBox1Click(Sender: TObject); var ChildItems: IXMLChildItems; I: Integer; begin if ListBox1.ItemIndex > -1 then begin ChildItems := CurrentMasterItem.Childitems; ListBox2.Clear; for I := 0 to ChildItems.Count - 1 do ListBox2.Items.AddObject(ChildItems[I].Name, TObject(ChildItems[I].Value)); XMLDocument1.Active := False; end; end; procedure TForm2.SaveButtonClick(Sender: TObject); var ChildItems: IXMLChildItems; ChildItem: IXMLChildItem; I: Integer; begin if ListBox1.ItemIndex > -1 then begin ListBox2.Items.AddObject('New item', TObject(543223)); ChildItems := CurrentMasterItem.Childitems; ChildItems.Clear; for I := 0 to ListBox2.Count - 1 do begin ChildItem := ChildItems.Add; ChildItem.Name := ListBox2.Items[I]; ChildItem.Value := Integer(ListBox2.Items.Objects[I]); end; XMLDocument1.SaveToFile(XMLDocument1.FileName); XMLDocument1.Active := False; end; end;

Update: This device created here:

 {*********************************************************} { } { XML Data Binding } { } { Generated on: 10-11-2011 23:25:30 } { Generated from: H:\Delphi\Test\XMLTest\Test.xml } { Settings stored in: H:\Delphi\Test\XMLTest\Test.xdb } { } {*********************************************************} unit Test; interface uses xmldom, XMLDoc, XMLIntf; type { Forward Decls } IXMLMasterItems = interface; IXMLMasterItem = interface; IXMLChildItems = interface; IXMLChildItem = interface; { IXMLMasterItems } IXMLMasterItems = interface(IXMLNodeCollection) ['{ACA35986-053A-40AE-92E8-2044BC5DADC6}'] { Property Accessors } function Get_Masteritem(Index: Integer): IXMLMasterItem; { Methods & Properties } function Add: IXMLMasterItem; function Insert(const Index: Integer): IXMLMasterItem; property Masteritem[Index: Integer]: IXMLMasterItem read Get_Masteritem; default; end; { IXMLMasterItem } IXMLMasterItem = interface(IXMLNode) ['{E6481675-AE5B-4166-A977-CA29EC97B78D}'] { Property Accessors } function Get_Name: WideString; function Get_Value: Integer; function Get_Childitems: IXMLChildItems; procedure Set_Name(Value: WideString); procedure Set_Value(Value: Integer); { Methods & Properties } property Name: WideString read Get_Name write Set_Name; property Value: Integer read Get_Value write Set_Value; property Childitems: IXMLChildItems read Get_Childitems; end; { IXMLChildItems } IXMLChildItems = interface(IXMLNodeCollection) ['{CD16D91C-30E5-45A1-AAA1-1C518C84EA5B}'] { Property Accessors } function Get_Childitem(Index: Integer): IXMLChildItem; { Methods & Properties } function Add: IXMLChildItem; function Insert(const Index: Integer): IXMLChildItem; property Childitem[Index: Integer]: IXMLChildItem read Get_Childitem; default; end; { IXMLChildItem } IXMLChildItem = interface(IXMLNode) ['{F7399037-A33F-4E43-ADF9-000EAD71B418}'] { Property Accessors } function Get_Name: WideString; function Get_Value: Integer; procedure Set_Name(Value: WideString); procedure Set_Value(Value: Integer); { Methods & Properties } property Name: WideString read Get_Name write Set_Name; property Value: Integer read Get_Value write Set_Value; end; { Forward Decls } TXMLMasteritemsType = class; TXMLMasteritemType = class; TXMLChilditemsType = class; TXMLChilditemType = class; { TXMLMasteritemsType } TXMLMasteritemsType = class(TXMLNodeCollection, IXMLMasterItems) protected { IXMLMasterItems } function Get_Masteritem(Index: Integer): IXMLMasterItem; function Add: IXMLMasterItem; function Insert(const Index: Integer): IXMLMasterItem; public procedure AfterConstruction; override; end; { TXMLMasteritemType } TXMLMasteritemType = class(TXMLNode, IXMLMasterItem) protected { IXMLMasterItem } function Get_Name: WideString; function Get_Value: Integer; function Get_Childitems: IXMLChildItems; procedure Set_Name(Value: WideString); procedure Set_Value(Value: Integer); public procedure AfterConstruction; override; end; { TXMLChilditemsType } TXMLChilditemsType = class(TXMLNodeCollection, IXMLChildItems) protected { IXMLChildItems } function Get_Childitem(Index: Integer): IXMLChildItem; function Add: IXMLChildItem; function Insert(const Index: Integer): IXMLChildItem; public procedure AfterConstruction; override; end; { TXMLChilditemType } TXMLChilditemType = class(TXMLNode, IXMLChildItem) protected { IXMLChildItem } function Get_Name: WideString; function Get_Value: Integer; procedure Set_Name(Value: WideString); procedure Set_Value(Value: Integer); end; { Global Functions } function Getmasteritems(Doc: IXMLDocument): IXMLMasterItems; function Loadmasteritems(const FileName: WideString): IXMLMasterItems; function Newmasteritems: IXMLMasterItems; const TargetNamespace = ''; implementation { Global Functions } function Getmasteritems(Doc: IXMLDocument): IXMLMasterItems; begin Result := Doc.GetDocBinding('masteritems', TXMLMasteritemsType, TargetNamespace) as IXMLMasterItems; end; function Loadmasteritems(const FileName: WideString): IXMLMasterItems; begin Result := LoadXMLDocument(FileName).GetDocBinding('masteritems', TXMLMasteritemsType, TargetNamespace) as IXMLMasterItems; end; function Newmasteritems: IXMLMasterItems; begin Result := NewXMLDocument.GetDocBinding('masteritems', TXMLMasteritemsType, TargetNamespace) as IXMLMasterItems; end; { TXMLMasteritemsType } procedure TXMLMasteritemsType.AfterConstruction; begin RegisterChildNode('masteritem', TXMLMasteritemType); ItemTag := 'masteritem'; ItemInterface := IXMLMasterItem; inherited; end; function TXMLMasteritemsType.Get_Masteritem(Index: Integer): IXMLMasterItem; begin Result := List[Index] as IXMLMasterItem; end; function TXMLMasteritemsType.Add: IXMLMasterItem; begin Result := AddItem(-1) as IXMLMasterItem; end; function TXMLMasteritemsType.Insert(const Index: Integer): IXMLMasterItem; begin Result := AddItem(Index) as IXMLMasterItem; end; { TXMLMasteritemType } procedure TXMLMasteritemType.AfterConstruction; begin RegisterChildNode('childitems', TXMLChilditemsType); inherited; end; function TXMLMasteritemType.Get_Name: WideString; begin Result := ChildNodes['name'].Text; end; procedure TXMLMasteritemType.Set_Name(Value: WideString); begin ChildNodes['name'].NodeValue := Value; end; function TXMLMasteritemType.Get_Value: Integer; begin Result := ChildNodes['value'].NodeValue; end; procedure TXMLMasteritemType.Set_Value(Value: Integer); begin ChildNodes['value'].NodeValue := Value; end; function TXMLMasteritemType.Get_Childitems: IXMLChildItems; begin Result := ChildNodes['childitems'] as IXMLChildItems; end; { TXMLChilditemsType } procedure TXMLChilditemsType.AfterConstruction; begin RegisterChildNode('childitem', TXMLChilditemType); ItemTag := 'childitem'; ItemInterface := IXMLChildItem; inherited; end; function TXMLChilditemsType.Get_Childitem(Index: Integer): IXMLChildItem; begin Result := List[Index] as IXMLChildItem; end; function TXMLChilditemsType.Add: IXMLChildItem; begin Result := AddItem(-1) as IXMLChildItem; end; function TXMLChilditemsType.Insert(const Index: Integer): IXMLChildItem; begin Result := AddItem(Index) as IXMLChildItem; end; { TXMLChilditemType } function TXMLChilditemType.Get_Name: WideString; begin Result := ChildNodes['name'].Text; end; procedure TXMLChilditemType.Set_Name(Value: WideString); begin ChildNodes['name'].NodeValue := Value; end; function TXMLChilditemType.Get_Value: Integer; begin Result := ChildNodes['value'].NodeValue; end; procedure TXMLChilditemType.Set_Value(Value: Integer); begin ChildNodes['value'].NodeValue := Value; end; end.
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Source: https://habr.com/ru/post/1392928/

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