(Delphi ActiveX) Find and Update an XML Attribute Value

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Demonstrates how to find an element in XML with a specified attribute name and then update the attribute value.

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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
xml1: TChilkatXml;
xml2: TChilkatXml;
phrase_id: WideString;
phrase_value: WideString;
sbPath: TChilkatStringBuilder;
i: Integer;
count_i: Integer;

begin
// Let's say you have 2 XML files with identical structures as shown directly below,
// and you wish to update the values in the 1st XML file with those in the 2nd XML file.

// <global>
//     <phrase id="2FADisabled" value="2factor authentication disabled"/>
//     <phrase id="2FAEnabled" value="2factor authentication enabled"/>
//     <phrase id="2FAResetFailed" value="Failed to disable two factor authentication"/>
// </global>

// <global>
//     <phrase id="2FAResetFailed" value="Failed to reset two factor authentication"/>
//     <phrase id="2FADisabled" value="2FA authentication disabled"/>
//     <phrase id="2FAEnabled" value="2FA authentication enabled"/>
// </global>

// First, initialize each of the Chilkat XML objects.
// These could be loaded from files, but we'll just create them manually for this example..

xml1 := TChilkatXml.Create(Self);
xml1.Tag := 'global';
xml1.UpdateAttrAt('phrase',1,'id','2FADisabled');
xml1.UpdateAttrAt('phrase',1,'value','2factor authentication disabled');
xml1.UpdateAttrAt('phrase[1]',1,'id','2FAEnabled');
xml1.UpdateAttrAt('phrase[1]',1,'value','2factor authentication enabled');
xml1.UpdateAttrAt('phrase[2]',1,'id','2FAResetFailed');
xml1.UpdateAttrAt('phrase[2]',1,'value','Failed to disable two factor authentication');

xml2 := TChilkatXml.Create(Self);
xml2.Tag := 'global';
xml2.UpdateAttrAt('phrase',1,'id','2FAResetFailed');
xml2.UpdateAttrAt('phrase',1,'value','Failed to reset two factor authentication');
xml2.UpdateAttrAt('phrase[1]',1,'id','2FADisabled');
xml2.UpdateAttrAt('phrase[1]',1,'value','2FA authentication disabled');
xml2.UpdateAttrAt('phrase[2]',1,'id','2FAEnabled');
xml2.UpdateAttrAt('phrase[2]',1,'value','2FA authentication enabled');

// Iterate over attribute values in xml2 and update the same in xml1.

sbPath := TChilkatStringBuilder.Create(Self);

i := 0;
count_i := xml2.NumChildrenHavingTag('phrase');
while i < count_i do
  begin
    xml2.I := i;
    phrase_id := xml2.ChilkatPath('phrase[i]|(id)');
    phrase_value := xml2.ChilkatPath('phrase[i]|(value)');

    // Notice how the UpdateAttrAt method's 1st argument is a Chilkat path -- which is an expression
    // to find the location of the XML element to be updated.
    // Here we create a path of the form "/A/tagName,attributeName,attributeValuePattern", which means
    // find the direct descendent of xml2 having tag=tagName, with an attribute=attributeName where the attribute value
    // matches the attributeValuePattern.  If attributeValuePattern does not contain a "*", then it must match directly.
    // We'll build a Chilkat path such as "/A/phrase,id,2FADisabled"
    sbPath.SetString('/A/phrase,id,');
    sbPath.Append(phrase_id);

    // This assumes the corresponding element exists in xml1.
    xml1.UpdateAttrAt(sbPath.GetAsString(),1,'value',phrase_value);

    i := i + 1;
  end;

// Now see how xml1 has been updated..
Memo1.Lines.Add(xml1.GetXml());

// <global>
//     <phrase id="2FADisabled" value="2FA authentication disabled"/>
//     <phrase id="2FAEnabled" value="2FA authentication enabled"/>
//     <phrase id="2FAResetFailed" value="Failed to reset two factor authentication"/>
// </global>
end;