Problems calling VBScript/COM objects from InstallScript

[Rincewind]

Can anyone tell whats wrong with this function?
It is supposed to create an VBscript Regexp object and then test a string against the expression and return the result of the test (TRUE/FALSE).
It always returns FALSE, even when it obviously should be TRUE - tested a simple expression. Am I missing something in how to call VBScript/COM objects and test return codes?

prototype BOOL ValidateString(STRING, STRING); 
function BOOL ValidateString(szString,szPattern)
OBJECT oRegEx, oMatch;  
BOOL MatchFound;
begin
	
	//try to create the RegEx object
	try
		set oRegEx = CreateObject("VBScript.RegExp");
	catch
		MessageBox("CreateObject Failed- "+ Err.Decription, SEVERE);
	endcatch;
	
	oRegEx.Pattern = szPattern;
	oRegEx.IgnoreCase = 0;
	oRegEx.Global = 1;  //set to 1 to find all matches in the string
			//set to 0 to find only the first match
	try
		set oMatch = oRegEx.Execute(szString);
	catch
		MessageBox("CreateObject Failed- "+ Err.Decription, SEVERE);
	endcatch;
	
	MatchFound = (oMatch.Count > 0);
	return MatchFound;
end;

Actually, that was a second attempt. The initial attempt was to call the Test method of REGEX directly, but that didn't work either.

prototype BOOL ValidateString(STRING, STRING); 
function BOOL ValidateString(szString,szPattern)
OBJECT oRegEx;  
BOOL MatchFound;
begin
	
	//try to create the RegEx object
	try
		set oRegEx = CreateObject("VBScript.RegExp");
	catch
		MessageBox("CreateObject Failed- "+ Err.Decription, SEVERE);
	endcatch;
	
	oRegEx.Pattern = szPattern;
	oRegEx.IgnoreCase = 0;
	oRegEx.Global = 1;  //set to 1 to find all matches in the string
			//set to 0 to find only the first match
	MatchFound = oRegEx.Test(szString);
	return MatchFound;
end;

This is being #included into a setup.rul in an InstallScriptMSI project.

[Rincewind]

Turns out I only needed to declare the Pattern variable as a "VARIANT".
Can be taken care of in the PROTOTYPE declaration:

prototype BOOL ValidateString(STRING, VARIANT);

The second set of code works great as a regular expression tester if anyone else is looking for one. Use the above prototype and this code:

function BOOL ValidateString(szString,szPattern)
OBJECT oRegEx;   
BOOL MatchFound;
begin
		            
	//try to create the RegEx object
	try
		set oRegEx = CoCreateObject("VBScript.RegExp");
	catch
		MessageBox("CoCreateObject Failed- "+ Err.Decription, SEVERE);
	endcatch;
	oRegEx.Pattern = szPattern;
	oRegEx.IgnoreCase = 0;
	MatchFound = oRegEx.Test(szString);  
	set oRegEx = NOTHING;
	return MatchFound;
end;

[bwknight]

I have tried your solution to validate a string

my regular expression is defined like so:
#define PATTERN "^[\w]*$"

That should match any string of alphanumeric characters, which is what I want.

I have tried calling the ValidateString method several different ways, in each instance it always returns FALSE.

How do you call the ValidateString method?

[Rincewind]

Originally Posted by bwknight

I have tried your solution to validate a string

my regular expression is defined like so:
#define PATTERN "^[\w]*$"

That should match any string of alphanumeric characters, which is what I want.

I have tried calling the ValidateString method several different ways, in each instance it always returns FALSE.

How do you call the ValidateString method?

I'm not using it anymore - the need went away.
But, a check in some older code showed the following:

	STRING	emailPattern;
	emailPattern="\w+@\w+\.\w+";
...
	elseif (!ValidateString(svMailAddr,emailPattern)) then
		MessageBox ("Invalid format for an email address.", WARNING);
		dlgCtrl = GetDlgItem (hwndDlg, RES_MAIL_ADDR);
		SetFocus (dlgCtrl);
		CtrlSelectText (szDialogName, RES_MAIL_ADDR);
...

Arguably not the best string for validating an email address, but it was working.
Make sure you are using the version from my corrected post and you've declared the PROTOTYPE correctly.

[Rincewind]

When generating your regular expression string, remember that Installscript will impose some requirements on your string:

embeded quotes must be escaped with a backslash (\)
embedded backslashes must also be escaped with a backslash (i.e. \\, not \)

My string in the previous post wouldn't work because the backslashes were only singled, not doubled.
That is, it should have been:

emailPattern="\\w+@\\w+\\.\\w+";

Here's a better example (though it probably isn't 100% accurate):

// real pattern: ^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,})$
emailPattern='^(([^<>()[\\]\\\\.,;:\\s@\\"]+(\\.[^<>()[\\]\\\\.,;:\\s@\\"]+)*)|(\\".+\\"))@(([a-zA-Z\\-0-9]+\\.)+[a-zA-Z]{2,})$';