=head1 NAME CGI::HTML::Functions - Documentation for CGI.pm Legacy HTML Functionality =head1 SYNOPSIS Nothing here - please do not use this functionality, it is considered to be legacy and essentially deprecated. This documentation exists solely to aid in maintenance and migration of legacy code using this functionality and you are strongly encouraged to migrate away from it. If you are working on new code you should be using a template engine. For more information see L. If you really want to continue using the HTML generation functionality of CGI.pm then you should take a look at L instead, which may give you a migration path away from CGI.pm's html generation functions; i strongly encourage you to move towards template driven page generation for anything involving markup as it will make porting your app to other frameworks much easier in the long run. =head1 DESCRIPTION The documentation here should be considered an addendum to the sections in the L documentation - the sections here are named the same as those within the CGI perldoc. =head1 Calling CGI.pm routines HTML tag functions have both attributes (the attribute="value" pairs within the tag itself) and contents (the part between the opening and closing pairs). To distinguish between attributes and contents, CGI.pm uses the convention of passing HTML attributes as a hash reference as the first argument, and the contents, if any, as any subsequent arguments. It works out like this: Code Generated HTML ---- -------------- h1()

h1('some','contents');

some contents

h1({-align=>left});

h1({-align=>left},'contents');

contents

Many newcomers to CGI.pm are puzzled by the difference between the calling conventions for the HTML shortcuts, which require curly braces around the HTML tag attributes, and the calling conventions for other routines, which manage to generate attributes without the curly brackets. Don't be confused. As a convenience the curly braces are optional in all but the HTML shortcuts. If you like, you can use curly braces when calling any routine that takes named arguments. For example: print $q->header( { -type => 'image/gif', -expires => '+3d' } ); If you use warnings, you will be warned that some CGI.pm argument names conflict with built-in perl functions. The most frequent of these is the -values argument, used to create multi-valued menus, radio button clusters and the like. To get around this warning, you have several choices: =over 4 =item 1. Use another name for the argument, if one is available. For example, -value is an alias for -values. =item 2. Change the capitalization, e.g. -Values =item 3. Put quotes around the argument name, e.g. '-values' =back =head2 Function-oriented interface HTML exports Here is a list of the HTML related function sets you can import: =over 4 =item B<:form> Import all fill-out form generating methods, such as B. =item B<:html2> Import all methods that generate HTML 2.0 standard elements. =item B<:html3> Import all methods that generate HTML 3.0 elements (such as , and ). =item B<:html4> Import all methods that generate HTML 4 elements (such as , and ). =item B<:netscape> Import the , and
tags. =item B<:html> Import all HTML-generating shortcuts (i.e. 'html2', 'html3', 'html4' and 'netscape') =item B<:standard> Import "standard" features, 'html2', 'html3', 'html4', 'ssl', 'form' and 'cgi'. =back If you import any of the state-maintaining CGI or form-generating methods, a default CGI object will be created and initialized automatically the first time you use any of the methods that require one to be present. This includes B, B, B and the like. (If you need direct access to the CGI object, you can find it in the global variable B<$CGI::Q>). =head2 Pragmas Additional HTML generation related pragms: =over 4 =item -nosticky By default the CGI module implements a state-preserving behavior called "sticky" fields. The way this works is that if you are regenerating a form, the methods that generate the form field values will interrogate param() to see if similarly-named parameters are present in the query string. If they find a like-named parameter, they will use it to set their default values. Sometimes this isn't what you want. The B<-nosticky> pragma prevents this behavior. You can also selectively change the sticky behavior in each element that you generate. =item -tabindex Automatically add tab index attributes to each form field. With this option turned off, you can still add tab indexes manually by passing a -tabindex option to each field-generating method. =item -no_xhtml By default, CGI.pm versions 2.69 and higher emit XHTML (http://www.w3.org/TR/xhtml1/). The -no_xhtml pragma disables this feature. Thanks to Michalis Kabrianis for this feature. If start_html()'s -dtd parameter specifies an HTML 2.0, 3.2, 4.0 or 4.01 DTD, XHTML will automatically be disabled without needing to use this pragma. =back =head2 Special forms for importing HTML-tag functions Many of the methods generate HTML tags. As described below, tag functions automatically generate both the opening and closing tags. For example: print h1('Level 1 Header'); produces

Level 1 Header

There will be some times when you want to produce the start and end tags yourself. In this case, you can use the form start_I and end_I, as in: print start_h1,'Level 1 Header',end_h1; =head2 Creating the HTML document header print start_html( -title => 'Secrets of the Pyramids', -author => 'fred@capricorn.org', -base => 'true', -target => '_blank', -meta => {'keywords'=>'pharaoh secret mummy', 'copyright' => 'copyright 1996 King Tut'}, -style => {'src'=>'/styles/style1.css'}, -BGCOLOR => 'blue' ); The start_html() routine creates the top of the page, along with a lot of optional information that controls the page's appearance and behavior. This method returns a canned HTML header and the opening tag. All parameters are optional. In the named parameter form, recognized parameters are -title, -author, -base, -xbase, -dtd, -lang and -target (see below for the explanation). Any additional parameters you provide, such as the unofficial BGCOLOR attribute, are added to the tag. Additional parameters must be proceeded by a hyphen. The argument B<-xbase> allows you to provide an HREF for the tag different from the current location, as in -xbase => "http://home.mcom.com/" All relative links will be interpreted relative to this tag. The argument B<-target> allows you to provide a default target frame for all the links and fill-out forms on the page. B B -target => "answer_window" All relative links will be interpreted relative to this tag. You add arbitrary meta information to the header with the B<-meta> argument. This argument expects a reference to a hash containing name/value pairs of meta information. These will be turned into a series of header tags that look something like this: To create an HTTP-EQUIV type of tag, use B<-head>, described below. The B<-style> argument is used to incorporate cascading stylesheets into your code. See the section on CASCADING STYLESHEETS for more information. The B<-lang> argument is used to incorporate a language attribute into the tag. For example: print $q->start_html( -lang => 'fr-CA' ); The default if not specified is "en-US" for US English, unless the -dtd parameter specifies an HTML 2.0 or 3.2 DTD, in which case the lang attribute is left off. You can force the lang attribute to left off in other cases by passing an empty string (-lang=>''). The B<-encoding> argument can be used to specify the character set for XHTML. It defaults to iso-8859-1 if not specified. The B<-dtd> argument can be used to specify a public DTD identifier string. For example: -dtd => '-//W3C//DTD HTML 4.01 Transitional//EN') Alternatively, it can take public and system DTD identifiers as an array: -dtd => [ '-//W3C//DTD HTML 4.01 Transitional//EN', 'http://www.w3.org/TR/html4/loose.dtd' ] For the public DTD identifier to be considered, it must be valid. Otherwise it will be replaced by the default DTD. If the public DTD contains 'XHTML', CGI.pm will emit XML. The B<-declare_xml> argument, when used in conjunction with XHTML, will put a declaration at the top of the HTML header. The sole purpose of this declaration is to declare the character set encoding. In the absence of -declare_xml, the output HTML will contain a tag that specifies the encoding, allowing the HTML to pass most validators. The default for -declare_xml is false. You can place other arbitrary HTML elements to the section with the B<-head> tag. For example, to place a element in the head section, use this: print start_html( -head => Link({ -rel => 'shortcut icon', -href => 'favicon.ico' }) ); To incorporate multiple HTML elements into the section, just pass an array reference: print start_html( -head => [ Link({ -rel => 'next', -href => 'http://www.capricorn.com/s2.html' }), Link({ -rel => 'previous', -href => 'http://www.capricorn.com/s1.html' }) ] ); And here's how to create an HTTP-EQUIV tag: print start_html( -head => meta({ -http_equiv => 'Content-Type', -content => 'text/html' }) ); JAVASCRIPTING: The B<-script>, B<-noScript>, B<-onLoad>, B<-onMouseOver>, B<-onMouseOut> and B<-onUnload> parameters are used to add JavaScript calls to your pages. B<-script> should point to a block of text containing JavaScript function definitions. This block will be placed within a