CALLING CGI FUNCTIONS THAT TAKE MULTIPLE ARGUMENTS

In versions of CGI.pm prior to 2.0, it could get difficult to remember the proper order of arguments in CGI function calls that accepted five or six different arguments. As of 2.0, there's a better way to pass arguments to the various CGI functions. In this style, you pass a series of name=>argument pairs, like this: 

   $field = $query->radio_group(-name=>'OS',
				-values=>[Unix,Windows,Macintosh],
				-default=>'Unix');

The advantages of this style are that you don't have to remember the exact order of the arguments, and if you leave out a parameter, in most cases it will default to some reasonable value. If you provide a parameter that the method doesn't recognize, it will usually do something useful with it, such as incorporating it into the HTML form tag. For example if Netscape decides next week to add a new JUSTIFICATION parameter to the text field tags, you can start using the feature without waiting for a new version of CGI.pm: 

   $field = $query->textfield(-name=>'State',
			      -default=>'gaseous',
			      -justification=>'RIGHT');

This will result in an HTML tag that looks like this: 

	<INPUT TYPE="textfield" NAME="State" VALUE="gaseous"
	       JUSTIFICATION="RIGHT">

Parameter names are case insensitive: you can use -name, or -Name or -NAME. You don't have to use the hyphen if you don't want to. After creating a CGI object, call the use_named_parameters() method with a nonzero value. This will tell CGI.pm that you intend to use named parameters exclusively: 

   $query = new CGI;
   $query->use_named_parameters(1);
   $field = $query->radio_group('name'=>'OS',
				'values'=>['Unix','Windows','Macintosh'],
				'default'=>'Unix');

Actually, CGI.pm only looks for a hyphen in the first parameter. So you can leave it off subsequent parameters if you like. Something to be wary of is the potential that a string constant like ``values'' will collide with a keyword (and in fact it does!) While Perl usually figures out when you're referring to a function and when you're referring to a string, you probably should put quotation marks around all string constants just to play it safe.