Open Source Web Development with LAMP Using Linux, Apache, MySQL, Perl, and PHP [Electronic resources] نسخه متنی

7.8 Form Widget Methods

The here document, though handy, may not be the best way to build every HTML page. CGI.pm provides several other methods to create widgets, including:

start_form()
start tag for the form

textfield()
tag for a text widget

textarea()
tag for a text area

radio_group()
tags for a radio button group

checkbox()
tag for a check box

popup_menu()
tag for a pop-up menu

scrolling_list()
tags for a scrolling list box

submit()
tag for a submit button

reset()
tag for a reset button

end_form()
</FORM>

The following example, /var/www/cgi-bin/widgets3.cgi, uses these methods and produces the same form shown in Figure 7.12. You can find its code at http://localhost/cgi/widgets3.cgi or www.opensourcewebbook.com/cgi/widgets3.cgi. To prove it works, load one of the URLs.

The if part is just like widgets2.cgi, so we won't show it here. The else part is of interest here:

}else{ 
# if we are here, then we need to build the form 
# so print the header, then the html 
print 
header(), 
start_html(-title   => ´An Example of Form Widgets´, 
-bgcolor => ´#ffffff´), 
h1(´An Example of Form Widgets´), 
start_form(), 
´Programming language: ´, 
textfield(-name => ´language´, -value => ´Perl´), 
br(), 
´Comments:´, 
br(), 
textarea(-name => ´comments´, 
-cols => 20, 
-rows => 5), 
br(), 
´Rate the coolness: ´, 
radio_group(-name    => ´coolness´, 
-values  => [´cool´, ´very cool´, ´ice cold´], 
-default => ´ice cold´), 
br(), 
´I will learn more about Perl and CGI: ´, 
checkbox(-name    => ´learnmore´, 
-value   => ´yes´, 
-label   => ´ Yes´, 
-checked => 1), 
br(), 
´I will use this operating system: ´, 
popup_menu(-name   => ´operating_system´, 
-values => [´Linux´, ´Solaris´, ´HPUX´], 
-size   => 1), 
br(), 
´My favorite animal(s): ´, 
scrolling_list(-name     => ´animal´, 
-values   => [´Penguin´, ´Camel´, ´Llama´, 
´Panther´], 
-size     => 3, 
-multiple => 1), 
br(), 
br(), 
submit(-value => ´Submit Form´), 
´ ´, 
reset(-value => ´Reset Form´), 
end_form(); 
} 

Here the various CGI.pm functions are used to produce the HTML for this form.

N

Notice that action="/cgi-bin/widgets.cgi" was not set in the start_form() method. CGI.pm is smart enough to set the action to the name of the CGI program it is used within.

CGI.pm offers these other methods to create form widgets:

start_multipart_form()
beginning tag for a multipart form

defaults()
tag for a defaults button

password_field()
tag for a password field (a text field containing data that won't be displayedit will be starred-out)

checkbox_group()
tags for a group of check boxes

filefield()
tag for a file upload widget (must use start_multipart_form())

hidden()
tag for a hidden field

image_button()
tag for an image button

button()
tag for a generic button

See the CGI.pm documents for further information.