How to read data from xml file and display it over the text box in delphi language

Question

I am new to the delphi language, and here I have a doubt, I have a xml file called vehicle.xml.

It looks like this

<data>
<vehicle>
    <type>Car</type>
    <model>2005</model>
    <number>1568</number>
</vehicle>
<vehicle>
    <type>Car</type>
    <model>2009</model>
    <number>1598</number>
</vehicle>
</data>

My Delphi form contains three text boxes:

• txtType
• txtModel
• txtnumber

While loading the page I want to display the contents of the vehicle.xml over the text box like:

• txtType=Car
• txtModel=2005
• txtNumber="1568"

Answer 1

Have a look at Delphi's own TXMLDocument component, for example:

uses
  ..., XMLIntf, XMLDoc;

procedure TForm1.FormCreate(Sender: TObject);
var
  Vehicle: IXMLNode;
begin
  XMLDocument1.FileName :='vehicle.xml';
  XMLDocument1.Active := True;
  try
    Vehicle := XMLDocument.DocumentElement;
    txtType.Text := Vehicle.ChildNodes['type'].Text;
    txtModel.Text := Vehicle.ChildNodes['model'].Text;
    txtnumber.Text  := Vehicle.ChildNodes['number'].Text;
  finally
    XMLDocument1.Active := False;
  end;
end;

Alternatively, use the IXMLDocument interface directly (which TXMLDocument implements):

uses
  ..., XMLIntf, XMLDoc;

procedure TForm1.FormCreate(Sender: TObject);
var
  Doc: IXMLDocument;
  Vehicle: IXMLNode;
begin
  Doc := LoadXMLDocument('vehicle.xml');
  Vehicle := Doc.DocumentElement;
  txtType.Text := Vehicle.ChildNodes['type'].Text;
  txtModel.Text := Vehicle.ChildNodes['model'].Text;
  txtnumber.Text := Vehicle.ChildNodes['number'].Text;
end;

---

Update: the XML in the question has been altered to now wrap the vehicle element inside of a data element, and to have multiple vehicle elements. So the code above has to be adjusted accordingly, eg:

uses
  ..., XMLIntf, XMLDoc;

procedure TForm1.FormCreate(Sender: TObject);
var
  Doc: IXMLDocument;
  Data: IXMLNode;
  Node: IXMLNode;
  I: Integer;
begin
  Doc := LoadXMLDocument('vehicle.xml');
  Data := Doc.DocumentElement;
  for I := 0 to Data.ChildNodes.Count-1 do
  begin
    Node := Data.ChildNodes[I];
    // if all of the child nodes will always be 'vehicle' only
    // then this check can be removed...
    if Node.LocalName = 'vehicle' then
    begin
      // use Node.ChildNodes['type'], Node.ChildNodes['model'],
      // and Node.ChildNodes['number'] as needed...
    end;
  end;
end;