(Delphi DLL) Traverse Direct Children via FirstChild / NextSibling, or LastChild / PreviousSibling

Demonstrates some ways to iterate over direct child nodes using the FirstChild / NextSibling and LastChild / PreviousSibling methods.

The input XML, available at http://www.chilkatsoft.com/data/fruit.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>

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Xml;

...

procedure TForm1.Button1Click(Sender: TObject);
var
xml: HCkXml;
child: HCkXml;
nextSibling: HCkXml;
prevSibling: HCkXml;
success: Boolean;
bContinue: Boolean;

begin
xml := CkXml_Create();

success := CkXml_LoadXmlFile(xml,'qa_data/xml/fruit.xml');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkXml__lastErrorText(xml));
    Exit;
  end;

// Iterate over the direct children by using FirstChild / NextSibling
child := CkXml_FirstChild(xml);
bContinue := CkXml_getLastMethodSuccess(xml);
while (bContinue = True) do
  begin
    Memo1.Lines.Add(CkXml__tag(child) + ' : ' + CkXml__content(child));
    nextSibling := CkXml_NextSibling(child);
    bContinue := CkXml_getLastMethodSuccess(child);
    CkXml_Dispose(child);
    child := nextSibling;
  end;

Memo1.Lines.Add('-----');

// Do the same, but with FirstChild2 / NextSibling2 to avoid
// creating so many XML object instances:
success := CkXml_FirstChild2(xml);
while success = True do
  begin
    Memo1.Lines.Add(CkXml__tag(xml) + ' : ' + CkXml__content(xml));
    success := CkXml_NextSibling2(xml);
  end;

// Revert back up to the parent:
success := CkXml_GetParent2(xml);

Memo1.Lines.Add('-----');

// Iterate in reverse order using LastChild / PreviousSibling
child := CkXml_LastChild(xml);
bContinue := CkXml_getLastMethodSuccess(xml);
while (bContinue = True) do
  begin
    Memo1.Lines.Add(CkXml__tag(child) + ' : ' + CkXml__content(child));
    prevSibling := CkXml_PreviousSibling(child);
    bContinue := CkXml_getLastMethodSuccess(child);
    CkXml_Dispose(child);
    child := prevSibling;
  end;

Memo1.Lines.Add('-----');

// Do the same, but with LastChild2 / PreviousSibling2 to avoid
// creating so many XML object instances:
success := CkXml_LastChild2(xml);
while success = True do
  begin
    Memo1.Lines.Add(CkXml__tag(xml) + ' : ' + CkXml__content(xml));
    success := CkXml_PreviousSibling2(xml);
  end;

// Revert back up to the parent:
success := CkXml_GetParent2(xml);

CkXml_Dispose(xml);

end;