This is indeed a problem.. I've encountered it myself after creating half a zillion checkboxes and then wanting to perform delete operations on the unchecked fields.

There may be better solutions, but one way I might approach this is to create (for every checkbox) a hidden field with a similar name to the name assigned for the checkbox. If my checkbox name was name="checkbox_284" then I'd name my hidden field name="hidden_checkbox_284".

In my CGI form I'd have a loop that goes something like:

  foreach my $param ( $cgi->param ) {
      next if ( $param !~ m/^hidden_(.+)$/ );
      my $checkboxname=$1;

      if ( ! $cgi->param( $checkboxname ) ) {
          # delete this item
      } else {
          # add this item
      }
  }

[download]

update: So that, even if the browser doesn't send the checkbox parameters for the unchecked fields, at least the browser sends all the hidden fields and I can then use them to check for the existance of the checkbox field.

In reply to Re: How to take values from check box in CGI form? by monarch
in thread How to take values from check box in CGI form? by gube

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.