Lazarus Pascal

Iterate over Direct Child Nodes by Index

See more XML Examples

Demonstrates some ways to iterate over direct child nodes by index.

The input XML, available at http://www.chilkatsoft.com/data/get_child.xml, is this:

<root>
    <fruit color="red">apple</fruit>
    <fruit color="green">pear</fruit>
    <veg color="orange">carrot</veg>
    <meat animal="cow">beef</meat>
    <xyz>
        <fruit color="blue">blueberry</fruit>
        <veg color="green">broccoli</veg>
    </xyz>
    <fruit color="purple">grape</fruit>
    <cheese color="yellow">cheddar</cheese>
</root>

Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Xml;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  xml: TXml;
  child: TXml;
  i: Integer;

begin
  success := False;

  xml := TXml.Create;

  //  The sample input XML is available at http://www.chilkatsoft.com/data/get_child.xml
  success := xml.LoadXmlFile('get_child.xml');
  if (success <> True) then
    begin
      WriteLn(xml.LastErrorText);
      Exit;
    end;

  //  The NumChildren property contains the number of direct
  //  child nodes.  Note: The child nodes under "xyz" are NOT
  //  direct children of "root".  Therefore, the "root" node has
  //  7 direct children
  WriteLn('NumChildren = ' + xml.NumChildren);

  //  Iterate over the direct children by index. The first child
  //  is at index 0.

  for i := 0 to xml.NumChildren - 1 do
    begin
      //   access the tag and content directly by index:
      WriteLn(i + ': ' + xml.GetChildTagByIndex(i) + ' : ' + xml.GetChildContentByIndex(i));

    end;

  WriteLn('-----');

  //  Do the same as the above loop, but get the child node
  //  and access the Tag and Content properties:
  for i := 0 to xml.NumChildren - 1 do
    begin
      child := xml.GetChild(i);
      WriteLn(i + ': ' + child.Tag + ' : ' + child.Content);
      child.Free;
    end;

  WriteLn('-----');

  //  Do the same as the above loop, but instead of creating
  //  a new object instance for each child, call GetChild2 to
  //  update the object's reference instead.
  for i := 0 to xml.NumChildren - 1 do
    begin
      //  Navigate to the Nth child.  
      success := xml.GetChild2(i);
      WriteLn(i + ': ' + xml.Tag + ' : ' + xml.Content);
      //  Navigate back up to the parent:
      success := xml.GetParent2();
    end;

  WriteLn('-----');

  //  Notice that the Content of the "xyz" node is empty.  This is correct.
  //  The "xyz" node has no Content, but 2 direct children.


  xml.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.