Form validation using CGI

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

Hi Monks, Can anybody help me set up validation for my form. I want it to alert the user if fields are left blank.

At the moment when you press the submit button, it goes to the subroutine add_record_two, but I would like it to go through validation first. Here is the code that generates the form.

my %form = Vars();

if ($form{'action'} eq "addrecord") {
        &add_record;
}
elsif ($form{'action'} eq "add_record_two") {
        &add_record_two;
}

sub header {
$title = shift;
print qq~
<HTML>
<HEAD>
<TITLE> $title </TITLE>
<basefont face="Trebuchet MS,Arial,Helvetica" size="2">
</HEAD>
<BODY bgcolor="#FFFFFF">

<CENTER>
<H1>CHGMANT V2</H1>
~;
}

sub footer {
print qq~
<TABLE border=0 cellspacing=3 cellpadding=3>
<TR>
        <TD><a href="chgmant_v4.cgi?action=addrecord"><FONT COLOR="#00
+0000" size=-1>Add A Record</a></TD>
        <TD><a href="chgmant_v4.cgi?action=edit"><FONT COLOR="#000000"
+ size=-1>Modify a Record</TD>
        <TD><a href="chgmant_v4.cgi?action=delete"><FONT COLOR="#00000
+0" size=-1>Delete a Record</TD>
        <TD><a href="chgmant_v4.cgi?action=search"><FONT COLOR="#00000
+0" size=-1>Search</TD>
</TR>
</TABLE>
</CENTER>
</BODY>
</HTML>
~;
}

sub build_record_page {
my (%record) = @_;
my ($val) = "";
my ($html) = qq~<TABLE border=1 bgcolor="#FFFFFF" cellspacing=0 cellpa
+dding=4>
        <TR bgcolor="#C0C0C0">
                <TD colspan=2><CENTER><font size=-1> Record </CENTER><
+/TD>
        </TR>~;
        foreach $obj (@db_fields) {
                if ($obj eq $db_key) {
                        next; # ID's are dynamically made
                }
                $html .= qq~<TR bgcolor="#DDDDDD"><TD><FONT SIZE=-1>$d
+b_name{$obj}</TD><TD>~;
                if ($db_type{$obj} eq "text") {  # Makes the text box
                        if ($record{$obj}) { $val = qq~ VALUE="$record
+{$obj}"~; }
                        else { $val = ""; }
                        $html .= qq~<INPUT TYPE="text" NAME="$obj" siz
+e="20" $val>~;
                }
                if ($db_type{$obj} eq "drop" && $db_name{$obj} eq "Use
+rID:") {  # Makes the dropdown box
                        if ($record{$obj}) { $val = qq~ VALUE="$record
+{$obj}"~; }
                        else { $val = ""; }
                                        print "$record{$obj} $id\n"; #
+debug
                                         $html .= popup_menu ( -name =
+> $obj,
                                                                -value
+s=>\@users);
                }
                if ($db_type{$obj} eq "drop" && $db_name{$obj} eq "Typ
+e Of Change:") {  # Makes the dropdown box
                        if ($record{$obj}) { $val = qq~ VALUE="$record
+{$obj}"~; }
                        else { $val = ""; }
                                        print "$record{$obj} $id\n"; #
+debug
                                         $html .= popup_menu ( -name =
+> $obj,
                                                                -value
+s=>\@changetype);
                }
                elsif ($db_type{$obj} eq "textarea") { # Makes the tex
+tarea
                        if ($record{$obj}) { $val = qq~$record{$obj}~;
+ }
                        else { $val = ""; }
                        $html .= qq~<TEXTAREA NAME="$obj" ROWS="4" COL
+S="40">$val</TEXTAREA>~;
                }
                $html .= qq~</TD></TR>~;

        }
        $html .= "</TABLE><P>";
print $html;

}
sub add_record {
        &header("Add a Record");
        print qq~
        <CENTER>
        <FORM METHOD=POST>
        <INPUT TYPE="hidden" NAME="action" VALUE="add_record_two">~;
        &build_record_page;
        print qq~
        <CENTER>
        <INPUT TYPE="submit" value="Add Change"></CENTER>
        <CENTER>
        </FORM>~;
        &footer;
}

sub add_record_two {
        $form{$db_key} = &get_next_id();
        my ($line) = &make_data(%form);
        open (DATABASE, ">>".$file);
                if ($flock) {
                        flock(DATABASE, 2)
                }
        print DATABASE $line;
        close (DATABASE);
        &header("Add a Record Successful - $id");
        print qq~<CENTER>Here Is Your Record</CENTER><p>~;
        my (%result) = get_record($form{$db_key});
        print Dumper(%result);
        if (%result) {
        &build_record_page(%result);
        }
        else {
        print "Error - No Record Added";
        }
        &footer;
}
[download]

Thanks

Comment on Form validation using CGI Download Code

Replies are listed 'Best First'.
Re: Form validation using CGI by Anonymous Monk on Jul 31, 2008 at 09:23 UTC
Don't bother with Vars(), there are caveats you don't need to learn, its easier to use param. If you want validation, don't bother with CGI, start with Basic Tutorial - Step 1: Intro to FormBuilder, makes things really simple for you. More advanced : Validating Web forms with Perl Rapid Website Development with CGI::Application	[reply]
Re: Form validation using CGI by injunjoel (Priest) on Jul 31, 2008 at 20:41 UTC
Greetings, Though it could be fun/good to roll out your own solution, you might be interested in how it has been done (e.g. Data::FormValidator or FormValidator::Simple). While we're at it might I suggest looking over HTML::Template and HTML::FillInForm both of which could help you separate out the HTML from your code. two weeks in the lab can save you two hours in the library... -InjunJoel "I do not feel obliged to believe that the same God who endowed us with sense, reason and intellect has intended us to forego their use." -Galileo	[reply]


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