[Solved]: How to perform different actions before and after submit button is clicked.

Perl300 has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks,

I am trying to perform specific tasks in my CGI script depending on if the "Submit" button is clicked or not.

Basically, I have a dynamic webpage and I am trying to ensure that when the page is first called from browser, some code should be skipped. To do this, I am trying to put a check for Submit button.

I am trying to use $query->param('submit') with a sample code (Test.pl) like:

#!/usr/bin/perl

use strict;
use warnings;
use CGI::Carp qw(fatalsToBrowser);
use CGI qw/:standard/;
use CGI;

my $query = new CGI;
print $query->header;

print <<END_HTML;
        <html><head><title>Thank You</title></head>
        <body>
        <form method="post">
        <input type="submit" value="Submit" id="button1" />
        <br />Thank you - your form was submitted correctly!
        </body></html>
END_HTML

my $a = $query->param('submit');
print "Value: $a\n";
[download]

With this code when I access Test.pl from browser, it shows the page with submit button, but even after I click on submit nothing is stored $a.

Can you please help me find what I am missing here? My final goal is to run a chunk of code when the webpage is just fetched but Submit button is not clicked. After submit button is clicked, I am showing the resulting data in the same page.

Comment on [Solved]: How to perform different actions before and after submit button is clicked. Download Code

Replies are listed 'Best First'.
Re: How to perform different actions before and after submit button is clicked. by tangent (Parson) on Aug 31, 2015 at 23:12 UTC
To get the value of a form input you need to give it a name, so change your button to: `<input type="submit" name="button1" value="Submit" />` [download] Then you can see if it was clicked: `print '<html><head><title>Test</title></head><body>'; if ( $query->param('button1') ) { print 'Thank you - your form was submitted correctly!'; } else { print '<form method="post"><input type="submit" name="button1" val +ue="Submit"></form>'; } print '</body></html>';` [download]	[reply] [d/l] [select]
Re: How to perform different actions before and after submit button is clicked. by NetWallah (Canon) on Sep 01, 2015 at 03:04 UTC
You are printing the value of $a after `</body></html>` [download] so, it gets ignored. Try printing the value afer <body> but before the end </body>. Clarity: it's like that one thing that is not the other thing, except for when it is.	[reply] [d/l]
Re: How to perform different actions before and after submit button is clicked. by Perl300 (Friar) on Sep 01, 2015 at 13:56 UTC
Thank you tangent. I added name="submitButton" and then used $query->param('submitButton'); and it worked.I needed id for referring the button in css Thank you NetWallah for your response as well. Updating subject to mark resolved.	[reply]