in reply to Retrieving Form Data

Well, there's nothing wrong with this way of doing things, in theory, but the devil's in the details. I'm not entirely sure what the deal with "submit" is in your query string. Submit buttons, <input type="submit" name="submit"> will send thier values along in a form, so I don't think I'd use "submit" as the value to determine the state of my application.

Can you post some code to show how you're doing this? It's kind of hard to help you out with such a general question and no code. . .

Replies are listed 'Best First'.
Re: Re: Retrieving Form Data
by Monolith-0 (Beadle) on Jul 15, 2001 at 03:22 UTC
    Here's a sample of what sompage.pl might be like: 
    use strict;

if ($ARGV[0] eq "submit") {
   &submit_data;
}
else { $view_form; }

####################

sub view_form {
    print "<HTML>\n";
    print " <BODY>\n\n";
    
    print "  <FORM METHOD= \"POST\" ACTION= \"somepage.pl?submit\">\n"
+;
    print "   <B>Pass:</B> <INPUT TYPE= \"PASSWORD\" NAME= \"Pass\"><B
+R>\n";
    print "   <BR>\n";
    print "   <B>Name:</B> <INPUT TYPE= \"TEXT\" NAME= \"Name\"><BR>\n
+";
    print "   <B>URL:</B> <INPUT TYPE= \"TEXT\" NAME= \"URL\" SIZE=40>
+<BR>\n";
    
    print "   <INPUT TYPE= \"SUBMIT\" VALUE= \"Submit\">\n";
    print "  </FORM>\n";
    
    print " </BODY>\n";
    print "</HTML>\n";
}

####################

sub submit_data {
    # Get the data submitted from the form
    read(STDIN, my $buffer, $ENV{'CONTENT_LENGTH'});
    # Split the name-value pairs
    my @pairs = split(/&/, $buffer);
    my %FORM;
    foreach my $pair (@pairs) {
       my ($name, $value) = split(/=/, $pair);

       # Remove plus signs and decode %-encoding
       $value =~ tr/+/ /;
       $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
       $value =~ s/<!--(.|\n)*-->//g;

       $FORM{$name} = $value;
    }

    ## Do something with the data
}

    [download]

    - Monolith

[reply]
[d/l]

      Oh my. I'd probably do that differently, especially by using CGI.pm for my form decoding. There's a million different reasons to CGI, the best is that it makes your job much easier!

      Here's your code, using CGI.pm:

      #!/usr/bin/perl -wT
use strict;
use CGI;

my $q= CGI->new();

if (!$q->param('pass'){
 print_form($q); 
 } else {
 submit_data($q)
}

sub print_form{
 my $q =shift;
 print $q->header().
  $q->start_html().
  $start_form(-method=>'POST',
   -action=>'/cgi-bin/somepage.pl').
  $q->b('Pass:').
  $q->textfield(-name=>'pass').
  $q->br().
  $q->b('Name:').
  $q->textfield(-name=>'name').
  $q->br().
  $q->b('URL:').
  $q->textfield(-name=>'url').
  $q->submit().
  $q->end_form().
  $q->end_html();
}

sub submit_data{
 my $q=shift;
 # No need to go through all that form decoding stuff here. 
 # It's done automatically, and in the Right Way by CGI.pm.
 
 #do stuff with data.
}

      [download]

      Why is this better? Less typing, for one. Easier to read, too. Plus CGI.pm is very, very good for creating forms and simple HTML (it does a lot more than what I used it for here, obviously!). CGI.pm is also very good for creating tables programatically, e.g. from a database. You can even use CGI to auto-fill your forms, when you validate data from users.

      If you're going to be doing more complex HTML in your code, you should look into a templating system that lets you separate your perl scripts from your HTML. A really good one to learn is HTML::Template. It'll seem like a pain at first, but it's worth it in the long run.

      Some links:
      Use CGI or Die! from Ovid. Really good reading.
      Ovid's CGI tutorial.
      The CGI.pm docs from Lincoln Stein.
      HTML::Template Tutorial at PerlMonth.

      Update:The way I REALLY would have done this is with CGI::Application, which I think is like a state machine, and is HTML::Template's (non-)evil twin.

[reply]
[d/l]
        Yea, yea... I still need to get used to CGI. Thanks for the related links.
[reply]

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