NAME
Win32::ASP - a Module for ASP (PerlScript) Programming
SYNOPSIS
use Win32::ASP;
print "This is a test
";
$PageName = GetFormValue('PageName');
if($PageName eq 'Select a page...') {
die "Please go back and select a value from the Pages list";
}
print "You selected the ", $PageName, " page";
exit;
DESCRIPTION
These routines are some I knocked together one day when I was
saying the following: "Why don't my "print" statements output to
the browser?" and "Why doesn't exit and die end my script?". So
I started investigating how I could overload the core functions.
"print" is overloaded via the tie mechanism (thanks to Eryq
(eryq@zeegee.com), Zero G Inc. for the code which I ripped from
IO::Scalar). You can also get at print using the OO mechanism
with $Win32::ASP::SH->print(). Also added recently was code that
allowed cleanup stuff to be executed when you exit() or die(),
this comes in the form of the `AddDeathHook' function. The
`BinaryWrite' function simply wraps up unicode conversion and
BinaryWrite in one call. Finally I was annoyed that I couldn't
just develop a script using GET and then change to POST for
release because of the difference in how the ASP code handles
the different formats, GetFormValue solves that one.
Installation instructions
This now installs with MakeMaker, or I often have a ppd package
available at http://www.fastnetltd.ndirect.co.uk/Perl/zips
To install the ppd, extract the zip file somewhere, and in a dos
box cd to that directory and type "ppm install Win32-ASP.ppd".
To install via MakeMaker, it's the usual procedure - download
from CPAN, extract, type "perl Makefile.PL", "nmake" then "nmake
install". Don't do an "nmake test" because the ASP objects won't
be available and so won't work properly.
Function Reference
use Win32::ASP qw(:strict);
This allows you to use the ASP module in a "strict" perl script.
Normally under "use strict" PerlScript would complain that the
ASP objects ($Response, $Session etc) were not initialised:
"Global symbol "Response" requires explicit package name at -
line XXX".
To get around this I simply assign and assign back the
variables, and export them into the main namespace.
Note - you don't _have_ to do this. The symbols for Session,
Response etc are in the global symbol table and so are
accessible if you do "use vars qw/$Session $Response/;".
Print LIST
Prints a string or comma separated list of strings to the
browser. Use as if you were using print in a CGI application.
Print gets around ASP's limitations of 128k in a single
Response->Write call.
Obsolete - use `print' instead.
NB: `print' calls Print, so you could use either, but print is
more integrated with "the perl way".
DebugPrint LIST
The same as `Print' except the output is between HTML comments
so that you can only see it with "view source". DebugPrint is
not exported so you have to use it as Win32::ASP::DebugPrint()
This function is useful to debug your application. For example I
use it to print out SQL before it is executed.
HTMLPrint LIST
The same as `Print' except the output is taken and encoded so
that any html tags appear as sent, i.e. < becomes <, >
becomes > etc. HTMLPrint is not exported, so use it like
Win32::ASP::HTMLPrint.
This function is useful for printing output that comes from a
database or a file, where you don't have total control over the
input.
wprint LIST
Obsolete: Use `Print' instead
die LIST
Prints the contents of LIST to the browser and then exits. `die'
automatically calls $Response->End for you, it also executes any
cleanup code you have added with `AddDeathHook'.
exit
Exits the current script. $Response->End is called automatically
for you, and any cleanup code added with `AddDeathHook' is also
called.
HTMLEncode LIST
The same as HTMLPrint except the output is not printed but
returned as a scalar instead. HTMLEncode is not exported, so use
it like Win32::ASP::HTMLEncode.
This function is useful to handle output that comes from a
database or a file, where you don't have total control over the
input.
If an array ref is passed it uses the ref, otherwise it assumes
an array of scalars is used. Using a ref makes for less time
spent passing values back and forth, and is the prefered method.
GetFormValue EXPR [, EXPR]
returns the value passed from a form (or non-form GET request).
Use this method if you want to be able to develop in GET mode
(for ease of debugging) and move to POST mode for release. The
second (optional) parameter is for getting multiple parameters
as in:
http://localhost/scripts/test.asp?Q=a&Q=b
In the above GetFormValue("Q", 1) returns "a" and
GetFormValue("Q", 2) returns "b".
GetFormValue will work in an array context too, returning all
the values for a particular parameter. For example with the
above url:
my @AllQs = GetFormValue('Q');
will return an array: @AllQs = ('a', 'b')
Also just added: If you call GetFormValue without any parameters
it will return a list of Form parameters in the same way that
CGI.pm's param() function does. This allows easy iteration over
the form elements:
foreach my $key (GetFormValue()) {
print "$key = ", GetFormValue($key), "
\n";
}
Also added a param() function which works exactly as
GetFormValue does, for compatibility with CGI.pm.
GetFormCount EXPR
returns the number of times EXPR appears in the request (Form or
QueryString). Use this value as $i to iterate over
GetFormValue(EXPR, $i).
For example, url is:
http://localhost/scripts/myscript.asp?Q=a&Q=b
And code is:
my $numQs = GetFormCount('Q');
gives $numQs = 2
AddDeathHook LIST
This frightening sounding function allows you to have cleanup
code executed when you `die' or `exit'. For example you may want
to disconnect from your database if there is a problem:
<%
my $Conn = $Server->CreateObject('ADODB.Connection');
$Conn->Open( "DSN=BADEV1;UID=sa;DATABASE=ProjAlloc" );
$Conn->BeginTrans();
Win32::ASP::AddDeathHook( sub { $Conn->Close if $Conn; } );
%>
Now when you `die' because of an error, your database connection
will close gracefully, instead of you having loads of rogue
connections that you have to kill by hand, or restart your
database once a day.
Death hooks should be executed on a graceful exit of the script
too, but I've been unable to confirm this. If anyone has any
luck, let me know.
BinaryWrite LIST
Performs the same function as `$Response-'>`BinaryWrite()' but
gets around Perl's lack of unicode support, and the null padding
it uses to get around this.
Example:
Win32::ASP::BinaryWrite($val);
SetCookie Name, Value [, HASH]
Sets the cookie Name with the value Value. HASH is option, and
contains any of the following optional parameters:
* -expires => A CGI.pm style expires value (see the CGI.pm docs for header() for this).
* -domain => a domain in the style ".matt.com" that the cookie is returned to.
* -path => a path that the cookie is returned to.
* -secure => cookie only gets returned under SSL if this is true.
If Value is a hash ref, then it creates a cookie dictionary.
(see either the ASP docs, or my Introduction to PerlScript for
more info on Cookie Dictionaries).
Example:
Win32::ASP::SetCookie("Matt", "Sergeant", ( -expires => "+3h",
-domain => ".matt.com",
-path => "/users/matt",
-secure => 0 ));