NAME
HTML::Menu::Hierarchical - HTML Hierarchical Menu Generator
SYNOPSIS
my $menu_obj = HTML::Menu::Hierarchical->new($conf, \&callback);
my $html = $menu_obj->generateMenu($menu_item);
or
my $menu_obj = HTML::Menu::Hierarchical->new($conf, [ $obj, $method ]);
my $html = $menu_obj->generateMenu($menu_item);
In the first case, the callback is a function. In the second, the
callback is a method called on the given object.
The $conf parameter is a navigation configuration data structure
(described below).
DESCRIPTION
HTML::Menu::Hierarchical provides a way to easily
generate a hierarchical HTML menu without forcing a specific
layout. All output is provided by your own callbacks (subroutine
refs) and your own navigation configuration.
configuration data structure
A navigation configuration is a reference to an array whose
elements are hashrefs. Each hash contains configuration
information for one menu item and its children, if any. Consider
the following example:
my $conf = [
{ name => 'top_button_1',
info => { text => 'Top Level Button 1',
url => '/'
},
children => [
{ name => 'button_1_level_2',
info => { text => "Child 1 of Button 1",
url => '/child1.cgi'
},
},
]
},
{ name => 'top_button_2',
info => { text => 'Top Level Button 2',
url => '/top2.cgi'
},
callback => [ $obj, 'my_callback' ]
},
];
In each hash, the 'name' parameter should correspond to the
$menu_item parameter passed to the generateMenu() method.
This is how the module computes which menu item is selected.
This is generally passed via a CGI parameter, which can be
tacked onto the end of the url in your callback function.
Note that this parameter must be unique among all the array
entries. Otherwise, the module will not be able to decide
which menu item is selected.
The value of the 'info' parameter is available to your
callback function via the getInfo() method called on the
HTML::Menu::Hierarchical::ItemInfo object passed to the
callback function. In the above example, the 'info'
parameter contains text to be displayed as the menu item, and
a url the user is sent to when clicking on the menu item.
The 'children' parameter is a reference to another array
containing configuration information for child menu items.
This is where the Hierarchical part comes in. There is no
limit to depth of the hierarchy (until you run out of RAM,
anyway).
If a 'callback' parameter is specified that callback will be
used for that menu item instead of the global callback passed
to new().
callback functions/methods
Callback functions are passed a single parameter: an
HTML::Menu::Hierarchical::ItemInfo object. See the
documentation on this object for available methods. The
callback function should return the HTML necessary for the
corresponding menu item.
METHODS
new()
my $menu_obj = HTML::Menu::Hierarchical->new($conf, \&callback);
generateMenu()
my $html = $menu_obj->generateMenu($menu_item);
$menu_item is the 'name' parameter of the selected item,
typically passed as a CGI parameter.
addChildConf()
$menu_obj->addChildConf($conf, $menu_item_name);
Adds another configuration tree into the current
configuration at the specified node (name of the menu item).
There are also underscore_separated versions of these methods.
E.g., unescapeHtml($html) becomes unescape_html($html)
EXAMPLES
See the scripts in the examples subdirectory for example usages.
See the documentation for HTML::Menu::Hierarchical::ItemInfo for
methods available via the $info_obj parameter passed to the
menu_callback function below.
sub menu_callback { my ($info_obj) = @_; my $info_hash =
$info_obj->getInfo; my $level = $info_obj->getLevel;
my $text = $$info_hash{text};
$text = ' ' if $text eq '';
my $item_arg = $info_obj->getName;
# Add a cgi parameter m_i to url so we know which menu
# item was chosen
my $url = $info_obj->addArgsToUrl($$info_hash{url},
{ m_i => $item_arg });
my $dpy_text = $info_obj->isSelected ? "<$text>" : $text;
my $spacer = ' ' x $level;
my $str = qq{
\n};
$str .= qq{};
$str .= $spacer . $dpy_text;
$str .= qq{ | };
$str .= qq{
\n};
return $str;
}
TODO
Drop down to first url
Provide a way to skip being selected, e.g., if a menu item is
selected that contains no url to go to, default to the first of its
children that contains to a url.
Force open
Provide a way to specify that all menu items are open.
Last sibling
Provide a way to tell if the current menu item is the last of its
siblings to be displayed.
BUGS
Please send bug reports/feature requests to don@owensnet.com.
There are currently no checks for loops in the configuration data
structure passed to the module.
AUTHOR
Don Owens
COPYRIGHT
Copyright (c) 2003 Don Owens
All rights reserved. This program is free software; you can
redistribute it and/or modify it under the same terms as Perl
itself.
VERSION
0.05
NAME
HTML::Menu::Hierarchical::ItemInfo - Used by HTML::Menu::Hierarchical.
Provides information about the menu item being processed.
SYNOPSIS
Created by HTML::Menu::Hierarchical objects.
DESCRIPTION
Information holder/gatherer representing one menu item.
METHODS
Getting back information
hasChildren()
Returns true if the current item has child items in the configuration.
False otherwise.
isSelected()
Returns true if the current item is the selected one.
isInSelectedPath()
Returns true if the current item is in the path from the root of the
hierarchy to the selected item.
getSelectedItem()
Returns the ItemInfo object corresponding to the selected menu item.
getSelectedLevel()
Returns the level in the hierarchy where the selected menu item is
located. Levels start at zero.
getMaxDisplayedLevel()
Returns the maximum level in the hierarchy to currently be displayed.
isOpen()
Returns true if the current menu item is open, i.e., the current item
has child items and is also in the open path. Return false otherwise.
isFirstDisplayed()
Returns true if the current menu item is the first one to be displayed.
isLastDisplayed()
Returns true if the current menu item is the last to be displayed.
getInfo()
Returns the value of the 'info' field for the current menu item in the
navigation configuration.
Instead of getting the 'info' hash and then accessing a field within it,
you may call a method to get that field directly. This is implemented
with AUTOLOAD, so if you do something like
my $text = $info_obj->getText;
my $image_src = $info_obj->getImageSrc;
or
my $text = $info_obj->getText;
my $image_src = $info_obj->get_image_src;
you will be given back the corresponding values in the 'info' hash.
getName()
Returns the 'name' field for the current menu item in the navigation
configuration. This is used to determine which menu item has been
selected.
getNextItem()
Returns the ItemInfo object corresponding to the next displayed menu
item.
getPreviousItem()
Returns the ItemInfo object corrsponding to the previously displayed
menu item.
getLevel()
Returns the level in the menu hierarchy where the current menu item is
located. Levels start at zero.
getParent()
Returns the info object for the current item's parent.
Utilities
my $encoded = $info->urlEncode($plain_text)
URL encodes the given string. This does full url-encoding, so a space is
%20, not a '+'.
my $query = $info->urlEncodeVars($var_hash)
Takes a hash containing key/value pairs and returns a url-encoded query
string appropriate for adding to the end of a url. If a value is an
array, it is assumed to be a multivalued input field and is added to the
query string as such.
my $plain_text = $info->urlDecode($url_enc_str)
Decodes the given url-encoded string.
my $var_hash = $info->urlDecodeVars($url_enc_str)
Decodes the url-encoded query string and returns a hash contain
key/value pairs from the query string. If a field appears more than once
in the query string, it's value will be returned as a reference to an
array of values.
my $modified_url = $info->addArgsToUrl($url, $var_hash)
Takes the key/value pairs in $var_hash and tacks them onto the end of
$url as a query string.
my $html = $info->escapeHtml($text)
Escapes the given text so that it is not interpreted as HTML.
my $text = $info->unescapeHtml($html)
Unescape the escaped text.
There are also underscore_separated versions of these methods.
E.g., unescapeHtml($html) becomes unescape_html($html)
BUGS
Please send bug reports/feature requests to don@owensnet.com.
AUTHOR
Don Owens
COPYRIGHT
Copyright (c) 2003 Don Owens
All rights reserved. This program is free software; you can
redistribute it and/or modify it under the same terms as Perl
itself.
VERSION
$Id: README,v 1.4 2003/04/03 06:06:27 don Exp $