How do I parse this XML string in Delphi 2009?

Question

This is the information that the XML string has.

<?xml version="1.0" encoding="UTF-8"?>
<string xmlns="http://tempuri.org/">
<statusInfo><vendorClaimID>BRADY12478018AETNA</vendorClaimID>
<statusID>0</statusID><statusDescription>Unvalidated</statusDescription>
</statusInfo></string>

But this is how it comes in.. You will have to scroll to the right to see all of it.

'<?xml version="1.0" encoding="utf-8"?>'#$D#$A'<string xmlns="http://tempuri.org/">&lt;statusInfo&gt;&lt;vendorClaimID&gt;BRADY12478018AETNA&lt;/vendorClaimID&gt;&lt;statusID&gt;0&lt;/statusID&gt;&lt;statusDescription&gt;Unvalidated&lt;/statusDescription&gt;&lt;/statusInfo&gt;</string>'

I have loaded the string into a XMLDoc, but don't know how to access the values easily from here..

var
doc: IXMLDocument;


doc := LoadXMLData(xmlString);

Thanks!

Answer 1

Each node in the XML will be represented as an IXMLNode in the IXMLDocument, in the same hierarchy that they appear in the XML. It would help if you first look at the XML with the nodes indented so you can see the hierarchy more clearly:

<?xml version="1.0" encoding="UTF-8"?> 
<string xmlns="http://tempuri.org/"> 
  <statusInfo>
    <vendorClaimID>BRADY12478018AETNA</vendorClaimID> 
    <statusID>0</statusID>
    <statusDescription>Unvalidated</statusDescription> 
  </statusInfo>
</string> 

One you understand the hierarchy, you can write code for it:

var 
  doc: IXMLDocument;
  statusInfo: IXMLNode;
  vendorClaimID: String;
  statusID: Integer;
  statusDescription: String;
begin 
  doc := LoadXMLData(xmlString);
  statusInfo := doc.DocumentElement.ChildNodes['statusInfo'];
  vendorClaimID := statusInfo.ChildNodes['vendorClaimID'].Text;
  statusID := StrToInt(statusInfo.ChildNodes['statusID'].Text);
  statusDescription := statusInfo.ChildNodes['statusDescription'].Text; 
end;

Alternatively:

var 
  doc: IXMLDocument;
  statusInfo: IXMLNode;
  vendorClaimID: String;
  statusID: Integer;
  statusDescription: String;
begin 
  doc := LoadXMLData(xmlString);
  statusInfo := doc.DocumentElement.ChildNodes['statusInfo'];
  vendorClaimID := VarToStr(statusInfo.ChildValues['vendorClaimID']);
  statusID := StrToInt(VarToStr(statusInfo.ChildValues['statusID']));
  statusDescription := VarToStr(statusInfo.ChildValues['statusDescription']); 
end;

If you use Delphi's XML Data Binding wizard, it will generate interfaces that will parse the XML for you:

var 
  doc: IXMLDocument;
  statusInfo: IXMLstatusInfoType;
  vendorClaimID: String;
  statusID: Integer;
  statusDescription: String;
begin 
  doc := LoadXMLData(xmlString);
  statusInfo := Getstring(doc).statusInfo;
  vendorClaimID := statusInfo.vendorClaimID;
  statusID := statusInfo.statusID;
  statusDescription := statusInfo.statusDescription; 
end;

Answer 2

You can use XPath to extract the values of the nodes

Check this sample

{$APPTYPE CONSOLE}

{$R *.res}

uses
  MSXML,
  SysUtils,
  ActiveX,
  ComObj;


Const

XMLStr=
'<?xml version="1.0" encoding="UTF-8"?> '+
'<string xmlns="http://tempuri.org/">'+
' <statusInfo>'+
'  <vendorClaimID>BRADY12478018AETNA</vendorClaimID> '+
'  <statusID>0</statusID><statusDescription>Unvalidated</statusDescription> '+
' </statusInfo>'+
'</string> ';

procedure Test;
Var
  XMLDOMDocument  : IXMLDOMDocument;
  XMLDOMNode      : IXMLDOMNode;
begin
  XMLDOMDocument:=CoDOMDocument.Create;
  XMLDOMDocument.loadXML(XmlStr);
  XMLDOMNode := XMLDOMDocument.selectSingleNode('//string/statusInfo/vendorClaimID');
  if XMLDOMNode<>nil then
    Writeln(Format('vendorClaimID %s',[String(XMLDOMNode.Text)]));

  XMLDOMNode := XMLDOMDocument.selectSingleNode('//string/statusInfo/statusID');
  if XMLDOMNode<>nil then
    Writeln(Format('statusID %s',[String(XMLDOMNode.Text)]));

  XMLDOMNode := XMLDOMDocument.selectSingleNode('//string/statusInfo/statusDescription');
  if XMLDOMNode<>nil then
    Writeln(Format('statusDescription %s',[String(XMLDOMNode.Text)]));
end;


begin
 try
    CoInitialize(nil);
    try
      Test;
    finally
      CoUninitialize;
    end;
 except
    on E:EOleException do
        Writeln(Format('EOleException %s %x', [E.Message,E.ErrorCode]));
    on E:Exception do
        Writeln(E.Classname, ':', E.Message);
 end;
 Writeln('Press Enter to exit');
 Readln;
end.