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HTML-FromArrayref-1.06
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/ HTML::FromArrayref

NAME

HTML::FromArrayref - Output HTML described by a Perl data structure

VERSION

Version 1.06

SYNOPSIS

  use HTML::FromArrayref;
  print HTML [ html => [ head => [ title => 'My Web page' ] ], [ body => 'Hello' ] ];

EXPORT

This module exports an HTML() function that lets you easily print valid HTML without embedding it in your Perl code.

SUBROUTINES/METHODS

HTML(@)

Takes a list of strings and arrayrefs describing HTML content and returns the HTML string. The strings are encoded; each arrayref represents an HTML element, as follows:

  [ $tag_name, $attributes, @content ]

$tag_name

evaluates to a tag name such as 'html', 'head', 'title', 'body', 'table', 'tr', 'td', 'p', &c. If $tag_name is false then the whole element is replaced by its content.

If an arrayref's first element is another arrayref instead of an tag name, then the value of the first item of that array will be included in the HTML string but will not be encoded. This lets you include text in the HTML that has already been entity-encoded.

$attributes

is an optional hashref defining the element's attributes. If an attribute's value is undefined then the attribute will not appear in the generated HTML string. Attribute values will be encoded. If there isn't a hashref in the second spot in the element-definition list then the element won't have any attributes in the generated HTML.

@content

is another list of strings and arrayrefs, which will be used to generate the content of the element. If the content list is empty, then the element has no content and will be represented in the generated HTML string by adjacent start and end tags. The content of elements that are defined in the HTML 4.01 specification as "void" will be discarded, and only their start tag will be printed.

element()

Recursively renders HTML elements from arrayrefs

start_tag()

Takes a list with an element name and an optional hashref defining the element's attributes, and returns just the opening tag of the element. This and end_tag() are useful in those occasions when you really want to print out HTML piecewise procedurally, rather than building the whole page in memory.

end_tag()

Just takes an element name and returns the end tag for that element.

attributes()

Takes a hash of HTML element attributes and returns an encoded string for use in a tag

DOCTYPEs

These make it easy to add a valid doctype declaration to your document

EXAMPLES

Note that I've formatted the output HTML for clarity - the html() function returns it all machine-readable and compact.

Simple content

Strings are just encoded and printed, so

  print HTML 'Hi there, this & that';

would print

  Hi there, this & that

Literal content

If an element's name is an arrayref, its first item is printed without being encoded; this lets you include text that is already encoded by double-bracketing it:

  print HTML [ p => [[ '© Angel Networks™' ]] ];

would print

  <p>&copy; Angel Networks&trade;</p>

Using map to iterate, and optional elements

You can map any element over a list to iterate it, and by testing the value being mapped over can wrap some values in sub-elements:

  print HTML map [ p => [ $_ > 100 && 'b' => $_ ] ], 4, 450, 12, 44, 74, 102;

would print

  <p>4</p>
  <p><b>450</b></p>
  <p>12</p>
  <p>44</p>
  <p>74</p>
  <p><b>102</b></p>

Optional attributes

Similarly, by testing the value being mapped over in the attributes hash, you can set an attribute for only some values. Note that you have to explicitly return undef to skip the attribute since 0 is a valid value for an attribute.

  print HTML [ select => { name => 'State' },
    map
      [ option => { selected => $_ eq $c{state} || undef }, $_ ],
      @states
  ];

would print

  <select name="State">
    <option>Alabama</option>
    <option selected="1">Alaska</option>
    <option>Arkansas</option>
    ...
  </select>

assuming $c{state} equalled 'Alaska'.

Printing HTML tags one at a time

Sometimes you really don't want to build the whole page before printing it; you'd rather loop through some data and print an element at a time. The start_tag and end_tag functions will help you do this:

  print start_tag( [ td => { colspan => 3 } ] );
  print end_tag( 'td' );

would print

  <td colspan="3">
  </td>

SEE ALSO

The HTML 4.01 specification

AUTHOR

Nic Wolff, <nic@angel.net>

BUGS

Please report any bugs or feature requests through the web interface at https://github.com/nicwolff/HTML-FromArrayref/issues. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc HTML::FromArrayref

You can also look for information at:

LICENSE AND COPYRIGHT

Copyright 2012 Nic Wolff.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.