slloyd has asked for the wisdom of the Perl Monks concerning the following question:

Hi fellow monks, This one has me stumped. I want to use Win32::GUI::AxWindow to load an HTML page and then capture when a user clicks on a link in that page. My intention is to run a subroutine based on the link that is clicked. When I try to capture the BeforeNavigate2 event Perl blows up. I can capture other events fine. Here is the code. What am I doing wrong? 
#!perl
use strict;
use Win32::GUI;
use Win32::GUI::AxWindow;
################ MAIN WINDOW #############
my $FormWindow = new Win32::GUI::Window(
    -name   => "FormWindow",
    -text   => "Test",
    -pos    => [0,0],
    -size    => [400,300],
    );
sub FormWindow_Resize{return 0;}
sub FormWindow_Minimize {return 0;}
sub FormWindow_Maximize {return 0;}
sub FormWindow_Terminate {return -1;}
##########################
# Add a WebBrowser AxtiveX
my $Control = new Win32::GUI::AxWindow  (
    -parent  => $FormWindow,
    -name    => "Control",
    -control => "Shell.Explorer.2",
    #-control => "InternetExplorer.Application",
    #-control => "{8856F961-340A-11D0-A96B-00C04FD705A2}",
    -pos     => [0, 0],
    -size    => [400, 300],
    );  
# # Register some event
#    When I try to register the following events, Perl blows up.
#        NavigateComplete2
#        BeforeNavigate2
#        NewWindow2
#    These events work though
#        DownloadBegin
#        DocumentComplete
#        StatusTextChange

$Control->RegisterEvent("StatusTextChange",
    sub {
        my $self    = shift;
        my $eventid = shift;
        my $str=shift;
        print "Event [$eventid]: ", $str, "\n" if length($str) && $str
+ !~/done/is;
        } 
    );
print "Calling Navigate\n";
# Call Method
$Control->CallMethod("Navigate", 'http://www.google.com');
print "Done\n";
##########################
$FormWindow->Show();
Win32::GUI::Dialog();
exit;

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Replies are listed 'Best First'.
Re: Capturing a browser event in an ActiveX Browser Window
by tachyon (Chancellor) on Jun 15, 2004 at 09:08 UTC

    The immediate problem is the the BeforeNavigate2 event is incorrectly handled by AxWindow with the net result of trying to deref a null pointer (memory at 0x00000000). This is a bug in AxWindow, however there are also known bugs in BeforeNavigate2 just to add fun. As you can see StatusTextChange is a simple method, BN2 is more complex and needs to be fed appropriately - it is not being fed what it needs. I suggest you contact the author or if you want to do ActiveX in Perl I understand ActiveState has some commercial (ie pay for) tools that probably work. 

    void BeforeNavigate2(          
    IDispatch *pDisp,
    VARIANT *&url,
    VARIANT *&Flags,
    VARIANT *&TargetFrameName,
    VARIANT *&PostData,
    VARIANT *&Headers,
    VARIANT_BOOL *&Cancel
);

void StatusTextChange(          
    BSTR Text
);

    [download]

    cheers

    tachyon

[reply]
[d/l]
Re: Capturing a browser event in an ActiveX Browser Window
by dimar (Curate) on Jun 15, 2004 at 05:03 UTC

    This is one of those kinds of questions where the gut level reaction is "this person is not likely to get a satisfactory answer" ...

    Hopefully, the gut is wrong, but on the off chance that a more direct and satisfying solution is not forthcoming, perhaps you can try an alternative approach. The alternative is to use 'perlscript' directly in a web browser page hosted in Internet Explorer. If you want it, here is a sample that does what you were asking about. Admittedly, it is a far cry from the (apparently a spider?) application that you are working on.

    <html xmlns:ie="http://www.microsoft.com/windows/ie">
<head>
    <title>insert_title_here</title>
    <script language="perlscript">
        sub captureClick{
            if( $window->{event}{srcElement}{tagName} eq 'A'){
                alert('someone clicked a link!!');
            };
        }###end_sub
    </script>

</head>
<body  onclick="captureClick()">

    <a href="#">foo link</a>

</body>
</html>

    [download]
[reply]
[d/l]
      How'll that help the OP to track where user navigates? It wont
[reply]

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