CSCI A348/548
Lecture Notes Ten.One
Spring 2001 (Second semester 2000-2001)
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CSCI A348/548
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CGI.pm and CGI.
Here are some examples with CGI.pm
All forms elements with CGI.pm methods:
#!/usr/bin/perl
use CGI;
$query = new CGI;
print $query->header,
$query->start_html (-bgcolor=>'white',
-title=>'HTML Forms Widgets');
if ($query->request_method eq 'GET') {
&show_form;
} else {
print $query->dump, $query->hr;
&process_query;
}
print $query->end_html;
sub show_form { print
"\n", $query->start_form(-method=>'POST',
-action=>$query->url),
"\n", qq{This is a text field called fieldT1: <p>},
"\n", $query->textfield(-name=>'fieldT1',
-size=>20,
-maxlength=>40),
"\n", qq{<hr>Textarea called fieldT2: <p>},
"\n", $query->textarea(-name=>'fieldT2',
-default=>'Replace me with your answer',
-rows=>5,
-columns=>60),
"\n", qq{<hr>Password field called fieldPw: <p>},
"\n", $query->password_field(-name=>'fieldPw',
-size=>20,
-maxlength=>20),
"\n", qq{<hr>Popup menu field called fieldM: <p>},
"\n", $query->popup_menu(-name=>'fieldM',
-values=> [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
-labels=> { 1 => 'one', 2 => 'two',
3 => 'three', 4 => 'four',
5 => 'five', 6 => 'six',
7 => 'seven', 8 => 'eight',
9 => 'nine', 10 => 'ten'}),
"\n", qq{<hr>Scrolling list field called fieldSc: <p>},
"\n", $query->scrolling_list(-name=>'fieldSc',
-values=> [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
-size=>5, -multiple=>'true',
-labels=> { 1 => 'one', 2 => 'two',
3 => 'three', 4 => 'four',
5 => 'five', 6 => 'six',
7 => 'seven', 8 => 'eight',
9 => 'nine', 10 => 'ten'}),
"\n", qq{<hr>Group of checkboxes called fieldChk: <p>},
"\n", $query->checkbox_group(-name=>'fieldChk',
-linebreak=>'true',
-values=> [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
-labels=> { 1 => 'one', 2 => 'two',
3 => 'three', 4 => 'four',
5 => 'five', 6 => 'six',
7 => 'seven', 8 => 'eight',
9 => 'nine', 10 => 'ten'}),
"\n", qq{<hr>Group of radio buttons called fieldR: <p>},
"\n", $query->radio_group(-name=>'fieldR', -default=>'--',
-linebreak=>'true',
-values=> [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
-labels=> { 1 => 'one', 2 => 'two',
3 => 'three', 4 => 'four',
5 => 'five', 6 => 'six',
7 => 'seven', 8 => 'eight',
9 => 'nine', 10 => 'ten'}),
"\n", qq{<hr>A hidden field with name fieldH and value <em>discreet</em>: <p> },
"\n", $query->hidden(-name=>'fieldH', -default=>'discreet'),
"\n", qq{<hr> Submit button to send the contents of this form to the server: <p> },
"\n", qq{ Click here to}, $query->submit(-name=>'proceed'),
"\n", qq{<hr> Reset button to start again: <p> },
"\n", qq{ To reset the form to the original values: }, $query->reset,
$query->end_form;
}
sub process_query {
foreach $name ('fieldT1', 'fieldT2', 'fieldPw',
'fieldM', 'fieldSc', 'fieldChk', 'fieldR', 'fieldH') {
&process_param($name);
}
}
sub process_param {
my ($name) = @_;
if ($name eq 'fieldT1') {
$value = $query->param($name);
print $query->ul(
$query->li("Name: $name"),
$query->li("Value: " .
$query->escapeHTML($value)));
print $query->hr;
} elsif ($name eq 'fieldT2') {
$value = $query->param($name);
$value = $query->param($name);
print $query->ul(
$query->li("Name: $name"),
$query->li("Value: " .
$query->escapeHTML($value)));
print $query->hr;
} elsif ($name eq 'fieldPw') {
$value = $query->param($name);
$value = $query->param($name);
print $query->ul(
$query->li("Name: $name"),
$query->li("Value: " .
$query->escapeHTML($value)));
print $query->hr;
} elsif ($name eq 'fieldM') {
$value = $query->param($name);
$value = $query->param($name);
print $query->ul(
$query->li("Name: $name"),
$query->li("Value: " .
$query->escapeHTML($value)));
print $query->hr;
} elsif ($name eq 'fieldSc') {
@values = $query->param($name);
foreach $value (@values) {
$value = $query->escapeHTML($value);
}
print $query->ul(
$query->li("Name: $name"),
$query->li("Values: " .
$query->blockquote(join('<br>', @values))));
print $query->hr;
} elsif ($name eq 'fieldChk') {
@values = $query->param($name);
foreach $value (@values) {
$value = $query->escapeHTML($value);
}
print $query->ul(
$query->li("Name: $name"),
$query->li("Values: " .
$query->blockquote(join('<br>', @values))));
print $query->hr;
} elsif ($name eq 'fieldR') {
$value = $query->param($name);
$value = $query->param($name);
print $query->ul(
$query->li("Name: $name"),
$query->li("Value: " .
$query->escapeHTML($value)));
print $query->hr;
} elsif ($name eq 'fieldH') {
$value = $query->param($name);
$value = $query->param($name);
print $query->ul(
$query->li("Name: $name"),
$query->li("Value: " .
$query->escapeHTML($value)));
print $query->hr;
} else {
}
}
sub escapeHTML {
my ($string) = @_;
#
return $string;
}
CGI.pm (comments mailed to you by script):
#!/usr/bin/perl
use CGI;
$query = new CGI;
if ($query->request_method eq 'GET') {
&show_form;
} elsif ($query->request_method eq 'POST') {
&process_form;
} else {
&error('Unsupported request method.');
}
sub error { my ($message) = @_;
print $query->header,
$query->start_html(-bgcolor=>'white'),
qq{ $message }, $query->end_html;
}
sub process_form {
my $email, $message;
$message = $query->param('message');
$email = $query->param('email');
$email =~ s/\s//g;
if ($email =~ /^[a-zA-Z]+\@indiana.edu$/i) {
} elsif ($email =~ /^[a-zA-Z]+$/i) {
$email .= "\@indiana.edu";
} else { &error('Unsuported e-mail address format.'); }
open MAIL, "| mail $email dgerman\@indiana.edu ";
print MAIL $message;
close MAIL;
print $query->header,
$query->start_html(-bgcolor=>'white'),
qq{ Your message<blockquote>$message</blockquote> has
been sent to the webmaster. A copy has been sent
to the e-mail address that you indicated. },
$query->end_html;
}
sub show_form { print
$query->header,
$query->start_html(-bgcolor=>'white',
-title=>'feedback'),
$query->start_form(-method=>'POST',
-action=>$query->url),
qq{ Email address: },
$query->textfield(-name=>'email',
-size=>20,
-maxlength=>40),
$query->p, qq{Message: },
$query->textarea(-name=>'message',
-rows=>5,
-columns=>60,
-default=>'Replace me with your comments...'),
$query->p, $query->submit(-name=>'Proceed'), $query->end_form,
$query->end_html;
}
CGI.pm is easy: Note that the image acts as a submit button so we could not make this part of the form from the example above (that exemplifies the managing of HTML form widgets using CGI.pm).
However we will show later how Java and Javascript can cooperate to make a clickable image behave as a two-dimensional (graphical) radio button.
#!/usr/bin/perl
use CGI;
# use CGI::Carp 'fatalsToBrowser';
$query = new CGI;
print $query->header,
$query->start_html(-bgcolor=>'white', -title=>'Clickable Image');
if ($query->request_method eq 'GET') {
print $query->startform(-method=>'POST',
-action=>$query->url),
qq{ Please click on the image below and the server will return the X
and Y coordinates of that pixel within the image to you. <p> },
$query->image_button(-name=>'picture',
-src=>'http://www.cc.columbia.edu/low3.gif'),
$query->p, $query->endform;
} else { print $query->dump,
qq{ X coordinate: }, $query->param('picture.x'), $query->p,
qq{ Y coordinate: }, $query->param('picture.y'), $query->p;
}
print $query->end_html;
#!/usr/bin/perl
use CGI;
$query = new CGI;
print $query->header,
$query->start_html(-title=>'File Upload', -bgcolor=>'white');
if ($query->request_method eq 'GET') {
print qq{ Browse for a text file and push proceed to send it
to me. The file needs to be a plain ASCII (text) file. After
submission the file will be processed as follows: the vowels
will appear in red, the consonants in blue, and the rest of
the characters in light grey. The file will be returned to
your browser for display. Please use the Browse button below
to locate the file and send it to the processing script. <p> };
print $query->start_multipart_form(-method=>'POST',
-action=>$query->url),
"Filename: ", $query->filefield(-name=>'filename',
-size=>40),
$query->p,
$query->submit(-value=>'Proceed'),
$query->end_form;
} else {
if ($file = $query->param('filename')) {
print "This file sent for upload: <p> <pre>";
while (<$file>) {
# s/</</g;
# s/>/>/g;
s/(.)/<font color=lightgrey>$1<\/font>/g;
s/<font\s+color=lightgrey>([AEIOUaeiou])<\/font>
/<font color=red>$1<\/font>/gx;
s/<font color=lightgrey>([BCDFGHJKLMNPQRSTVWXYZbcdfghjklmnpqrstvwxyz])<\/font>/<font color=blue>$1<\/font>/g;
print $_;
} print "</pre>";
} else {
print "No file specified";
}
}
print $query->end_html;Documentation for CGI.pm.
And here now is a 1999 article on the state of CGI courtesy Lincoln Stein.
A348/A548