/ 
URL-Normalize-0.20
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/ URL::Normalize

NAME

URL::Normalize - Normalize/optimize URLs.

VERSION

Version 0.20

SYNOPSIS

use URL::Normalize;

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/display?lang=en&article=fred',
);

# ...or

my $normalizer = URL::Normalize->new(
    url  => '/display?lang=en&article=fred',
    base => 'http://www.example.com',
);

# Get a normalized URL back

$normalizer->do_all; # Perform all the normalizations available

print $normalizer->get_url; # or $normalizer->url;

DESCRIPTION

This is NOT a perfect solution. If you normalize a URL using all the methods in this module, there is a high probability that the URL will "stop working". This is merely a helper module for those of you who wants to either normalize a URL using only a few of the safer methods, and/or for those of you who wants to generate a unique "ID" from any given URL.

When writing a web crawler, for example, it's always very costly to check if a URL has been fetched/seen when you have millions or billions of URLs in a sort of database. This module can help you create a unique "ID", which you then can use as a key in a key/value-store; the key is the normalized URL, whereas all the URLs that converts to the normalized URL are part of the value (normally an array or hash);

'http://www.example.com/' = {
    'http://www.example.com:80/'        => 1,
    'http://www.example.com/index.html' => 1,
    'http://www.example.com/?'          => 1,
}

Above, all the URLs inside the hash normalizes to the key if you run these methods:

  • make_canonical

  • remove_directory_index

  • remove_empty_query

CONSTRUCTORS

new( %opts )

Constructs a new URL::Normalize object. Takes a hash as input argument;

my $normalizer = URL::Normalize->new(
    url  => '/foobar.html',            # required
    base => 'http://www.example.com/', # optional
);

METHODS

get_URI

Returns the URI object representing the current state of the URL.

get_url

Returns the current URL.

url

Returns the current URL.

get_base

Returns the current base.

make_canonical

Just a shortcut for URI::URL->new->canonical->as_string, and involves the following steps (at least):

  • Converts the scheme and host to lower case.

  • Capitalizes letters in escape sequences.

  • Decodes percent-encoded octets of unreserved characters.

  • Removes the default port (port 80 for http).

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/%7Eusername/',
);

$Normalize->make_canonical;

print $Normalize->get_url; # http://www.example.com/~username/

remove_dot_segments

The segments ".." and "." will be removed and "folded" (or flattened, if you prefer) from the URL.

This method does NOT follow the algorithm described in RFC 3986, but rather flattens each path segment. It works just as well, it seems, but keep in mind that it also doesn't account for symbolic links on the server side.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/../a/b/../c/./d.html',
);

$normalizer->remove_dot_segments;

print $normalizer->get_url; # http://www.example.com/a/c/d.html

remove_directory_index

Removes well-known directory indexes, eg. "index.html", "default.asp" etc.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/index.cgi?foo=/',
);

$normalizer->remove_directory_index;

print $normalizer->get_url; # http://www.example.com/?foo=/

You are free to modify the global $DIRECTORY_INDEX_REGEXPS arrayref to your own fitting:

$URL::Normalize::DIRECTORY_INDEX_REGEXPS = [ ... ];

Default values are:

$DIRECTORY_INDEX_REGEXPS = [
    '/default\.aspx?',
    '/index\.cgi',
    '/index\.php\d?',
    '/index\.pl',
    '/index\.s?html?',
];

sort_query_parameters

Sorts the query parameters alphabetically.

Uppercased parameters will be lowercased during sorting only, and if there are multiple values for a parameter, the key/value-pairs will be sorted as well.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/?b=2&c=3&a=0&A=1',
);

$normalizer->sort_query_parameters;

print $normalizer->get_url; # http://www.example.com/?a=0&A=1&b=2&c=3

remove_duplicate_query_parameters

Removes duplicate query parameters, i.e. where the key/value combination is identical with another key/value combination.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/?a=1&a=2&b=4&a=1&c=4',
);

$normalizer->remove_duplicate_query_parameters;

print $normalizer->get_url; # http://www.example.com/?a=1&a=2&b=3&c=4

remove_empty_query_parameters

Removes empty query parameters, i.e. where there are keys with no value.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/?a=1&b=&c=3',
);

$Normalize->remove_empty_query_parameters;

print $normalizer->get_url; # http://www.example.com/?a=1&c=3

remove_empty_query

Removes empty query from the URL.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/foo?',
);

$normalizer->remove_empty_query;

print $Normalize->get_url; # http://www.example.com/foo

remove_fragment

Removes the fragment from the URL, but only if they are at the end of the URL.

For example "http://www.example.com/#foo" will be translated to "http://www.example.com/", but "http://www.example.com/#foo/bar" will stay the same.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/bar.html#section1',
);

$normalizer->remove_fragment;

print $normalizer->get_url; # http://www.example.com/bar.html

You should probably use this with caution, as most web frameworks today allows fragments for logic, for example:

http://www.example.com/players#all
http://www.example.com/players#banned
http://www.example.com/players#top

...can all result in very different results, despite their "unfragmented" URL being the same.

remove_fragments

Removes EVERYTHING after a '#'. You should use this sparsely, because a lot of web applications these days returns different output in response to what the fragment is, for example:

http://www.example.com/users#list
http://www.example.com/users#edit

...etc.

remove_duplicate_slashes

Remove duplicate slashes from the URL.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/foo//bar.html',
);

$normalizer->remove_duplicate_slashes;

print $normalizer->get_url; # http://www.example.com/foo/bar.html

remove_hostname_prefix

Removes 'www' followed by a potential number before the actual hostname.

Example:

my $normalizer = URL::Normalize->new(
    url => 'http://www.example.com/',
);

$normalizer->remove_hostname_prefix;

print $normalizer->get_url; # http://example.com/

remove_social_query_parameters

Removes query parameters that are used for "social tracking".

For example, a lot of newspapers posts links to their articles on Twitter, and adds a lot of "noisee" in the URL so that they are able to track the number of users clicking on that specific URL. This method attempts to remove those query parameters.

You are free to modify the global $SOCIAL_QUERY_PARAMETERS arrayref to your own fitting:

$URL::Normalize::SOCIAL_QUERY_PARAMETERS = [ ... ];

Default values are:

$SOCIAL_QUERY_PARAMETERS = [
    'ncid',
    'utm_campaign',
    'utm_medium',
    'utm_source',
];

do_all

Performs all of the normalization methods mentioned above.

SEE ALSO

AUTHOR

Tore Aursand, <toreau at gmail.com>

BUGS

Please report any bugs or feature requests to the web interface at https://rt.cpan.org/Dist/Display.html?Name=URL-Normalize

SUPPORT

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

perldoc URL::Normalize

You can also look for information at:

LICENSE AND COPYRIGHT

Copyright 2012-2014 Tore Aursand.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.