Check XML for version using Inno Setup Installer

Question

I have a small Inno script that checks the registry for you current .Net installation and returns a bool...

[Code]
function IsDotNetDetected(version: string; service: cardinal): Boolean;
// Indicates whether the specified version and service pack of the .NET Framework is installed.
//
// version -- Specify one of these strings for the required .NET Framework version:
//    'v1.1.4322'     .NET Framework 1.1
//    'v2.0.50727'    .NET Framework 2.0
//    'v3.0'          .NET Framework 3.0
//    'v3.5'          .NET Framework 3.5
//    'v4\Client'     .NET Framework 4.0 Client Profile
//    'v4\Full'       .NET Framework 4.0 Full Installation
//
// service -- Specify any non-negative integer for the required service pack level:
//    0               No service packs required
//    1, 2, etc.      Service pack 1, 2, etc. required
var
    key: string;
    install, serviceCount: cardinal;
    success: boolean;
begin
    key := 'SOFTWARE\Microsoft\NET Framework Setup\NDP\' + version;
    // .NET 3.0 uses value InstallSuccess in subkey Setup
    if Pos('v3.0', version) = 1 then begin
        success := RegQueryDWordValue(HKLM, key + '\Setup', 'InstallSuccess', install);
    end else begin
        success := RegQueryDWordValue(HKLM, key, 'Install', install);
    end;
    // .NET 4.0 uses value Servicing instead of SP
    if Pos('v4', version) = 1 then begin
        success := success and RegQueryDWordValue(HKLM, key, 'Servicing', serviceCount);
    end else begin
        success := success and RegQueryDWordValue(HKLM, key, 'SP', serviceCount);
    end;
    result := success and (install = 1) and (serviceCount >= service);
end;

function CheckDotNet(): Boolean;
begin
    if not IsDotNetDetected('v4\Full', 0) then begin
        //MsgBox('{#gsAppName} requires Microsoft .NET Framework 4.0 Full.'#13#13
        //    'Please use Windows Update to install this version,'#13
        //    'and then re-run the {#gsAppName} setup program.', mbInformation, MB_OK);
        result := false;
    end else
        result := true;
end;

I want to see if it would be possible to do the same thing but on an XML file. I have the following XML file located at 'C:\test_folder\test.xml'.

<Registry>
   <HKEY_LOCAL_MACHINE>
      <SOFTWARE>
         <KOFAX>
            <CONDOR Value="0" Type="integer">
               <VERSION Value="V4.10.039"/>

Anyone know how to check that version and to check if it is above 4.0? With the .Net function I simply call CheckDotNet() that then in turn calls IsDotNetDetected('v4\Full', 0) I want to do the same thing with this XML file. I want the function to check if my version "V4.10.039" is greater then "4.0" by calling something like IsMySoftwareDetected('4.0').

Answer 1

I know I'm quite late :-) Just wanted to complete your question since the InnoSetup code example linked in the above comment doesn't exactly cover what you've asked.

The script file:

[Setup]
AppName=My Program
AppVersion=1.5
DefaultDirName={pf}\My Program

[Files]
Source: "ProductVersion.xml"; Flags: dontcopy;

[Code]
// this function opens the XML file and returns the value of XML node
// attribute specified by the given XPath expression
function GetAttrValueFromXML(const AFileName, APath: string): string;
var
  XMLNode: Variant;
  XMLDocument: Variant;  
begin
  Result := '';
  XMLDocument := CreateOleObject('Msxml2.DOMDocument.6.0');
  try
    XMLDocument.async := False;
    XMLDocument.load(AFileName);
    if (XMLDocument.parseError.errorCode <> 0) then
      MsgBox('The XML file could not be parsed. ' + 
        XMLDocument.parseError.reason, mbError, MB_OK)
    else
    begin
      XMLDocument.setProperty('SelectionLanguage', 'XPath');
      XMLNode := XMLDocument.selectSingleNode(APath);
      Result := XMLNode.NodeValue;
    end;
  except
    MsgBox('An error occured!', mbError, MB_OK);
  end;
end;

// function that strips out all non-numeric values and returns what
// remains as an integer, so you should keep the version string format
function GetVersionValue(const Value: string): Integer;
var
  S: string;
  I: Integer;
begin
  S := Value;
  for I := Length(Value) downto 1 do
    if not ((Ord(S[I]) >= Ord('0')) and (Ord(S[I]) <= Ord('9'))) then
      Delete(S, I, 1);
  Result := StrToInt(S);
end;

procedure InitializeWizard;
var
  S: string;
  I: Integer;
begin
  // extract the XML file containing the version information temporarly
  ExtractTemporaryFile('ProductVersion.xml');
  // read the attribute value specified by the XPath expression
  S := GetAttrValueFromXML(ExpandConstant('{tmp}\ProductVersion.xml'),
    '//Registry/HKEY_LOCAL_MACHINE/SOFTWARE/KOFAX/CONDOR/VERSION/@Value');
  // the numeric part of the version string must be in a format X.XX.XXX
  // because the GetVersionValue function removes all non-numeric values
  // from that string and returns it as an integer value, and to compare
  // it with an integer constant they must match in the number of digits
  // following comparision means when the version is below 4.10.039 then
  if GetVersionValue(S) < 410039 then
    MsgBox('Version is below 4.10.039.', mbInformation, MB_OK)
  else
    MsgBox('Version equals or greater than 4.10.039.', mbInformation, MB_OK);
end;

The XML file (ProductVersion.xml):

<?xml version="1.0" encoding="utf-8"?>
<Registry>
  <HKEY_LOCAL_MACHINE>
    <SOFTWARE>
      <KOFAX>
        <CONDOR Value="0" Type="integer">
          <VERSION Value="V4.10.038"/>
        </CONDOR>
      </KOFAX>
    </SOFTWARE>
  </HKEY_LOCAL_MACHINE>
</Registry>