NAME
HTML::LinkList - Create a 'smart' list of HTML links.
SYNOPSIS
use HTML::LinkList qw(link_list);
# default formatting
my $html_links = link_list(current_url=>$url,
urls=>\@links_in_order,
labels=>\%labels,
descriptions=>\%desc);
# paragraph with ' :: ' separators
my $html_links = link_list(current_url=>$url,
urls=>\@links_in_order,
labels=>\%labels,
descriptions=>\%desc,
links_head=>'<p>',
links_foot=>'</p>',
pre_item=>'',
post_item=>''
pre_active_item=>'<em>',
post_active_item=>'</em>',
item_sep=>" :: ");
# multi-level list
my $html_links = link_tree(
current_url=>$url,
link_tree=>\@list_of_lists,
labels=>\%labels,
descriptions=>\%desc);
DESCRIPTION
This module contains a number of functions for taking sets of URLs and
labels and creating suitably formatted HTML. These links are "smart"
because, if given the url of the current page, if any of the links in
the list equal it, that item in the list will be formatted as a special
label, not as a link; this is a Good Thing, since the user would be
confused by clicking on a link back to the current page.
While many website systems have plugins for "smart" navbars, they are
specialized for that system only, and can't be reused elsewhere,
forcing people to reinvent the wheel. I hereby present one wheel, free
to be reused by anybody; just the simple functions, a backend, which
can be plugged into whatever system you want.
The default format for the HTML is to make an unordered list, but there
are many options, enabling one to have a flatter layout with any
separators you desire, or a more complicated list with differing
formats for different levels.
The "link_list" function uses a simple list of links -- good for a
simple navbar.
The "link_tree" function takes a set of nested links and makes the HTML
for them -- good for making a table of contents, or a more complicated
navbar.
The "full_tree" function takes a list of paths and makes a full tree of
all the pages and index-pages in those paths -- good for making a site
map.
The "breadcrumb_trail" function takes a url and makes a "breadcrumb
trail" from it.
The "nav_tree" function creates a set of nested links to be used as a
multi-level navbar; one can give it a list of paths (as for full_tree)
and it will only show the links related to the current URL.
FUNCTIONS
To export a function, add it to the 'use' call.
use HTML::LinkList qw(link_list);
To export all functions do:
use HTML::LinkList ':all';
link_list
$links = link_list(
current_url=>$url,
urls=>\@links_in_order,
labels=>\%labels,
descriptions=>\%desc,
pre_desc=>' ',
post_desc=>'',
links_head=>'<ul>',
links_foot=>'</ul>',
pre_item=>'<li>',
post_item=>'</li>'
pre_active_item=>'<em>',
post_active_item=>'</em>',
item_sep=>"\n");
Generates a simple list of links, from list of urls (and optional
labels) taking into account of the "current" URL.
This provides a large number of options to customize the appearance of
the list. The default setup is for a simple UL list, but setting the
options can enable you to make it something other than a list
altogether, or add in CSS styles or classes to make it look just like
you want.
Required:
urls
The urls in the order you want them displayed. If this list is empty,
then nothing will be generated.
Options:
current_url
The link to the current page. If one of the links equals this, then
that is deemed to be the "active" link and is just displayed as a
label rather than a link.
descriptions
Optional hash of descriptions, to put next to the links. The keys of
this hash are the urls.
hide_ext
If a site is hiding link extensions (such as using MultiViews with
Apache) you may wish to hide the extensions (while using the full
URLs to check various things). (default: 0 (false))
item_sep
String to put between items.
labels
A hash whose keys are links and whose values are labels. These are
the labels for the links; if no label is given, then the last part of
the link is used for the label, with some formatting.
links_head
String to begin the list with.
links_foot
String to end the list with.
pre_desc
String to prepend to each description.
post_desc
String to append to each description.
pre_item
String to prepend to each item.
post_item
String to append to each item.
pre_active_item
An additional string to put in front of each "active" item, after
pre_item. The "active" item is the link which matches 'current_url'.
pre_item_active
INSTEAD of the "pre_item" string, use this string for active items
post_active_item
An additional string to append to each active item, before post_item.
prefix_url
A prefix to prepend to all the links. (default: empty string)
link_tree
$links = link_tree(
current_url=>$url,
link_tree=>\@list_of_lists,
labels=>\%labels,
descriptions=>\%desc,
pre_desc=>' ',
post_desc=>'',
links_head=>'<ul>',
links_foot=>'</ul>',
subtree_head=>'<ul>',
subtree_foot=>'</ul>',
pre_item=>'<li>',
post_item=>'</li>'
pre_active_item=>'<em>',
post_active_item=>'</em>',
item_sep=>"\n",
tree_sep=>"\n",
formats=>\%formats);
Generates nested lists of links from a list of lists of links. This is
useful for things such as table-of-contents or site maps.
By default, this will return UL lists, but this is highly configurable.
Required:
link_tree
A list of lists of urls, in the order you want them displayed. If a
url is not in this list, it will not be displayed.
Options:
current_url
The link to the current page. If one of the links equals this, then
that is deemed to be the "active" link and is just displayed as a
label rather than a link.
descriptions
Optional hash of descriptions, to put next to the links. The keys of
this hash are the urls.
exclude_root_parent
If this is true, then the "current_parent" display options are not
used for the "root" ("/") path, it isn't counted as a "parent" of the
current_url.
formats
A reference to a hash containing advanced format settings. For
example:
my %formats = (
# level 1 and onwards
'1' => {
tree_head=>"<ol>",
tree_foot=>"</ol>\n",
},
# level 2 and onwards
'2' => {
tree_head=>"<ul>",
tree_foot=>"</ul>\n",
},
# level 3 and onwards
'3' => {
pre_item=>'(',
post_item=>')',
item_sep=>",\n",
tree_sep=>' -> ',
tree_head=>"<br/>\n",
tree_foot=>"",
}
);
The formats hash enables you to control the formatting on a per-level
basis. Each key of the hash corresponds to a level-number; the
sub-hashes contain format arguments which will apply from that level
onwards. If an argument isn't given in the sub-hash, then it will
fall back to the previous level (or to the default, if there is no
setting for that format-argument for a previous level).
The only difference between the names of the arguments in the
sub-hash and in the global format arguments is that instead of
'subtree_head' and subtree_foot' it uses 'tree_head' and 'tree_foot'.
hide_ext
If a site is hiding link extensions (such as using MultiViews with
Apache) you may wish to hide the extensions (while using the full
URLs to check various things). (default: 0 (false))
item_sep
The string to separate each item.
labels
A hash whose keys are links and whose values are labels. These are
the labels for the links; if no label is given, then the last part of
the link is used for the label, with some formatting.
links_head
The string to prepend the top-level tree with. (default: <ul>)
links_foot
The string to append to the top-level tree. (default: </ul>)
pre_desc
String to prepend to each description.
post_desc
String to append to each description.
pre_item
String to prepend to each item. (default: <li>)
post_item
String to append to each item. (default: </li>)
pre_active_item
An additional string to put in front of each "active" item, after
pre_item. The "active" item is the link which matches 'current_url'.
(default: <em>)
pre_item_active
INSTEAD of the "pre_item" string, use this string for active items
post_active_item
An additional string to append to each active item, before post_item.
(default: </em>)
pre_current_parent
An additional string to put in front of a link which is a parent of
the 'current_url' link, after pre_item.
pre_item_current_parent
INSTEAD of the "pre_item" string, use this for links which are
parents of the 'current_url' link.
post_current_parent
An additional string to append to a link which is a parent of the
'current_url' link, before post_item.
prefix_url
A prefix to prepend to all the links. (default: empty string)
subtree_head
The string to prepend to lower-level trees. (default: <ul>)
subtree_foot
The string to append to lower-level trees. (default: </ul>)
tree_sep
The string to separate each tree.
full_tree
$links = full_tree(
paths=>\@list_of_paths,
labels=>\%labels,
descriptions=>\%desc,
hide=>$hide_regex,
nohide=>$nohide_regex,
start_depth=>0,
end_depth=>0,
top_level=>0,
preserve_order=>0,
preserve_paths=>0,
...
);
Given a set of paths this will generate a tree of links in the style of
link_tree. This will figure out all the intermediate paths and
construct the nested structure for you, clustering parents and children
together.
The formatting options are as for "link_tree".
Required:
paths
A reference to a list of paths: that is, URLs relative to the top of
the site.
For example, if the full URL is http://www.example.com/foo.html then
the path is /foo.html
If the full URL is http://www.example.com/~frednurk/foo.html then the
path is /foo.html
This does not require that every possible path be given; all the
intermediate paths will be figured out from the list.
Options:
append_list
Array of paths to append to the top-level links. They are used as-is,
and are not part of the processing done to the "paths" list of paths.
(see "prepend_list")
descriptions
Optional hash of descriptions, to put next to the links. The keys of
this hash are the paths.
end_depth
End your tree at this depth. If zero, then go all the way. (see
"start_depth")
exclude_root_parent
If this is true, then the "current_parent" display options are not
used for the "root" ("/") path, it isn't counted as a "parent" of the
current_url.
hide
If the path matches this string, don't include it in the tree.
hide_ext
If a site is hiding link extensions (such as using MultiViews with
Apache) you may wish to hide the extensions (while using the full
URLs to check various things). (default: 0 (false))
labels
Hash containing replacement labels for one or more paths. If no label
is given for '/' (the root path) then 'Home' will be used.
last_subtree_head
The string to prepend to the last lower-level tree. Only used if
end_depth is not zero.
last_subtree_foot
The string to append to the last lower-level tree. Only used if
end_depth is not zero.
nohide
If the path matches this string, it will be included even if it
matches the 'hide' string.
prefix_url
A prefix to prepend to all the links. (default: empty string)
prepend_list
Array of paths to prepend to the top-level links. They are used
as-is, and are not part of the processing done to the "paths" list of
paths.
preserve_order
Preserve the ordering of the paths in the input list of paths;
otherwise the links will be sorted alphabetically. Note that if
preserve_order is true, the structure is at the whims of the order of
the original list of paths, and so could end up odd-looking.
(default: false)
preserve_paths
Do not extract intermediate paths or reorder the input list of paths.
This speeds things up, but assumes that the input paths are complete
and in good order. (default: false)
start_depth
Start your tree at this depth. Zero is the root, level 1 is the
files/sub-folders in the root, and so on. (default: 0)
top_level
Decide which level is the "top" level. Useful when you set the
start_depth to something greater than 1.
breadcrumb_trail
$links = breadcrumb_trail(
current_url=>$url,
labels=>\%labels,
descriptions=>\%desc,
links_head=>'<p>',
links_foot=>"\n</p>",
subtree_head=>'',
subtree_foot=>"\n",
pre_item=>'',
post_item=>'',
pre_active_item=>'<em>',
post_active_item=>'</em>',
item_sep=>"\n",
tree_sep=>' > ',
...
);
Given the current url, make a breadcrumb trail from it. By default,
this is laid out with '>' separators, but it can be set up to give a
nested set of UL lists (as for "full_tree").
The formatting options are as for "link_tree".
Required:
current_url
The current url to be made into a breadcrumb-trail.
Options:
descriptions
Optional hash of descriptions, to put next to the links. The keys of
this hash are the urls.
exclude_root_parent
If this is true, then the "current_parent" display options are not
used for the "root" ("/") path, it isn't counted as a "parent" of the
current_url.
hide_ext
If a site is hiding link extensions (such as using MultiViews with
Apache) you may wish to hide the extensions (while using the full
URLs to check various things). (default: 0 (false))
labels
Hash containing replacement labels for one or more URLS. If no label
is given for '/' (the root path) then 'Home' will be used.
nav_tree
$links = nav_tree(
paths=>\@list_of_paths,
labels=>\%labels,
current_url=>$url,
hide=>$hide_regex,
nohide=>$nohide_regex,
preserve_order=>1,
descriptions=>\%desc,
...
);
This takes a list of links, and the current URL, and makes a nested
navigation tree, consisting of (a) the top-level links (b) the links
leading to the current URL (c) the links on the same level as the
current URL, (d) the related links just above this level, depending on
whether this is an index-page or a content page.
Optionally one can hide links which match match the 'hide' option.
The formatting options are as for "link_tree", with some additions.
Required:
current_url
The link to the current page. If one of the links equals this, then
that is deemed to be the "active" link and is just displayed as a
label rather than a link. This is also used to determine which links
to show and which ones to filter out.
paths
A reference to a list of paths: that is, URLs relative to the top of
the site.
For example, if the full URL is http://www.example.com/foo.html then
the path is /foo.html
This does not require that every possible path be given; all the
intermediate paths will be figured out from the list.
Options:
append_list
Array of paths to append to the top-level links. They are used as-is,
and are not part of the processing done to the "paths" list of paths.
(see "prepend_list")
descriptions
Optional hash of descriptions, to put next to the links. The keys of
this hash are the paths.
end_depth
End your tree at this depth. If zero, then go all the way. By default
this is set to the depth of the current_url.
exclude_root_parent
If this is true, then the "current_parent" display options are not
used for the "root" ("/") path, it isn't counted as a "parent" of the
current_url.
hide
If a path matches this string, don't include it in the tree.
hide_ext
If a site is hiding link extensions (such as using MultiViews with
Apache) you may wish to hide the extensions (while using the full
URLs to check various things). (default: 0 (false))
labels
Hash containing replacement labels for one or more paths. If no label
is given for '/' (the root path) then 'Home' will be used.
last_subtree_head
The string to prepend to the last lower-level tree.
last_subtree_foot
The string to append to the last lower-level tree.
nohide
If the path matches this string, it will be included even if it
matches the 'hide' string.
prefix_url
A prefix to prepend to all the links. (default: empty string)
prepend_list
Array of paths to prepend to the top-level links. They are used
as-is, and are not part of the processing done to the "paths" list of
paths.
preserve_order
Preserve the ordering of the paths in the input list of paths;
otherwise the links will be sorted alphabetically. (default: true)
preserve_paths
Do not extract intermediate paths or reorder the input list of paths.
This speeds things up, but assumes that the input paths are complete
and in good order. (default: false)
start_depth
Start your tree at this depth. Zero is the root, level 1 is the
files/sub-folders in the root, and so on. (default: 1)
top_level
Decide which level is the "top" level. Useful when you set the
start_depth to something greater than 1.
Private Functions
These functions cannot be exported.
make_item
$item = make_item( this_label=>$label, this_link=>$link, hide_ext=>0,
current_url=>$url, current_parents=>\%current_parents,
descriptions=>\%desc, format=>\%format, );
%format = ( pre_desc=>' ', post_desc=>'', pre_item=>'<li>',
post_item=>'</li>' pre_active_item=>'<em>', post_active_item=>'</em>',
pre_current_parent=>'<em>', post_current_parent=>'</em>',
item_sep=>"\n"); );
Format a link item.
See "link_list" for the formatting options.
this_label
The label of the required link. If there is no label, this uses the
base-name of the last part of the link, capitalizing it and replacing
underscores and dashes with spaces.
this_link
The URL of the required link.
current_url
The link to the current page. If one of the links equals this, then
that is deemed to be the "active" link and is just displayed as a
label rather than a link.
current_parents
URLs of the parents of the current item.
descriptions
Optional hash of descriptions, to put next to the links. The keys of
this hash are the links (not the labels).
defer_post_item
Don't add the 'post_item' string if this is true. (needed for nested
lists) (default: false)
no_link
Don't make a link for this, just a label.
make_canonical
my $new_url = make_canonical($url);
Make a URL canonical; remove the 'index.*' and add on a needed '/' --
this assumes that directory names never have a '.' in them.
get_index_path
my $new_url = get_index_path($url);
Get the "index" part of this path. That is, if this path is not for an
index-page, then get the parent index-page path for this path. (Removes
the trailing slash).
get_index_parent
my $new_url = get_index_parent($url);
Get the parent of the "index" part of this path. (Removes the trailing
slash).
path_depth
my $depth = path_depth($url);
Calculate the "depth" of the given path.
link_is_active
if (link_is_active(this_link=>$link, current_url=>$url))
...
Check if the given link is "active", that is, if it matches the
'current_url'.
traverse_lol
$links = traverse_lol(\@list_of_lists, labels=>\%labels,
tree_depth=>$depth current_format=>\%format, ... );
Traverse the list of lists (of urls) to produce a nested collection of
links.
This consumes the list_of_lists!
extract_all_paths
my @all_paths = extract_all_paths(paths=>\@paths, preserve_order=>0);
Extract all possible paths out of a list of paths. Thus, if one has
/foo/bar/baz.html
then that would make
/ /foo/ /foo/bar/ /foo/bar/baz.html
If 'preserve_order' is true, this preserves the ordering of the paths
in the input list; otherwise the output paths are sorted
alphabetically.
extract_current_parents
my %current_parents = extract_current_parents(current_url=>$url,
exclude_root_parent=>0);
Extract the "parent" paths of the current url
/foo/bar/baz.html
then that would make
/ /foo/ /foo/bar/
If 'exclude_root_parent' is true, then the '/' is excluded from the
list of parents.
build_lol
my @lol = build_lol(
paths=>\@paths,
current_url=>$url,
navbar_type=>'',
);
Build a list of lists of paths, given a simple list of paths. Assumes
that this list has already been filtered.
paths
Reference to list of paths; this is consumed.
filter_out_paths
my @filtered_paths = filter_out_paths(
paths=>\@paths,
current_url=>$url,
hide=>$hide,
nohide=>$nohide,
start_depth=>$start_depth,
end_depth=>$end_depth,
top_level=>$top_level,
navbar_type=>'',
);
Filter out the paths we don't want from our list of paths. Returns a
list of the paths we want.
make_default_format
my %default_format = make_default_format(%args);
Make the default format hash from the args. Returns a hash of format
options.
make_extra_formats
my %formats = make_extra_formats(%args);
Transforms the subtree_head and subtree_foot into the "formats" method
of formatting. Returns a hash of hashes of format options.
REQUIRES
Test::More
INSTALLATION
To install this module, run the following commands:
perl Build.PL
./Build
./Build test
./Build install
Or, if you're on a platform (like DOS or Windows) that doesn't like the
"./" notation, you can do this:
perl Build.PL
perl Build
perl Build test
perl Build install
In order to install somewhere other than the default, such as in a
directory under your home directory, like "/home/fred/perl" go
perl Build.PL --install_base /home/fred/perl
as the first step instead.
This will install the files underneath /home/fred/perl.
You will then need to make sure that you alter the PERL5LIB variable to
find the modules.
Therefore you will need to change the PERL5LIB variable to add
/home/fred/perl/lib
PERL5LIB=/home/fred/perl/lib:${PERL5LIB}
SEE ALSO
perl(1).
BUGS
Please report any bugs or feature requests to the author.
AUTHOR
Kathryn Andersen (RUBYKAT)
perlkat AT katspace dot com
http://www.katspace.com/tools/html_linklist/
COPYRIGHT AND LICENCE
Copyright (c) 2006 by Kathryn Andersen
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.