[catagits/DOM-Tiny.git] / README.pod

=pod

=encoding utf8

=head1 NAME

DOM::Tiny - Minimalistic HTML/XML DOM parser with CSS selectors

=head1 SYNOPSIS

  use DOM::Tiny;

  # Parse
  my $dom = DOM::Tiny->new('<div><p id="a">Test</p><p id="b">123</p></div>');

  # Find
  say $dom->at('#b')->text;
  say $dom->find('p')->map('text')->join("\n");
  say $dom->find('[id]')->map(attr => 'id')->join("\n");

  # Iterate
  $dom->find('p[id]')->reverse->each(sub { say $_->{id} });

  # Loop
  for my $e ($dom->find('p[id]')->each) {
    say $e->{id}, ':', $e->text;
  }

  # Modify
  $dom->find('div p')->last->append('<p id="c">456</p>');
  $dom->find(':not(p)')->map('strip');

  # Render
  say "$dom";

=head1 DESCRIPTION

L<DOM::Tiny> is a minimalistic and relaxed pure-perl HTML/XML DOM parser based
on L<Mojo::DOM>. It supports the L<HTML Living Standard|https://html.spec.whatwg.org/>
and L<Extensible Markup Language (XML) 1.0|http://www.w3.org/TR/xml/>, and
matching based on L<CSS3 selectors|http://www.w3.org/TR/selectors/>. It will
even try to interpret broken HTML and XML, so you should not use it for
validation.

=head1 NODES AND ELEMENTS

When we parse an HTML/XML fragment, it gets turned into a tree of nodes.

  <!DOCTYPE html>
  <html>
    <head><title>Hello</title></head>
    <body>World!</body>
  </html>

There are currently eight different kinds of nodes, C<cdata>, C<comment>,
C<doctype>, C<pi>, C<raw>, C<root>, C<tag> and C<text>. Elements are nodes of
the type C<tag>.

  root
  |- doctype (html)
  +- tag (html)
     |- tag (head)
     |  +- tag (title)
     |     +- raw (Hello)
     +- tag (body)
        +- text (World!)

While all node types are represented as L<DOM::Tiny> objects, some methods like
L</"attr"> and L</"namespace"> only apply to elements.

=head1 CASE-SENSITIVITY

L<DOM::Tiny> defaults to HTML semantics, that means all tags and attribute
names are lowercased and selectors need to be lowercase as well.

  # HTML semantics
  my $dom = DOM::Tiny->new('<P ID="greeting">Hi!</P>');
  say $dom->at('p[id]')->text;

If XML processing instructions are found, the parser will automatically switch
into XML mode and everything becomes case-sensitive.

  # XML semantics
  my $dom = DOM::Tiny->new('<?xml version="1.0"?><P ID="greeting">Hi!</P>');
  say $dom->at('P[ID]')->text;

XML detection can also be disabled with the L</"xml"> method.

  # Force XML semantics
  my $dom = DOM::Tiny->new->xml(1)->parse('<P ID="greeting">Hi!</P>');
  say $dom->at('P[ID]')->text;

  # Force HTML semantics
  my $dom = DOM::Tiny->new->xml(0)->parse('<P ID="greeting">Hi!</P>');
  say $dom->at('p[id]')->text;

=head1 OPERATORS

L<DOM::Tiny> overloads the following operators.

=head2 array

  my @nodes = @$dom;

Alias for L</"child_nodes">.

  # "<!-- Test -->"
  $dom->parse('<!-- Test --><b>123</b>')->[0];

=head2 bool

  my $bool = !!$dom;

Always true.

=head2 hash

  my %attrs = %$dom;

Alias for L</"attr">.

  # "test"
  $dom->parse('<div id="test">Test</div>')->at('div')->{id};

=head2 stringify

  my $str = "$dom";

Alias for L</"to_string">.

=head1 METHODS

L<DOM::Tiny> implements the following methods.

=head2 new

  my $dom = DOM::Tiny->new;
  my $dom = DOM::Tiny->new('<foo bar="baz">I ♥ DOM::Tiny!</foo>');

Construct a new scalar-based L<DOM::Tiny> object and L</"parse"> HTML/XML
fragment if necessary.

=head2 all_text

  my $trimmed   = $dom->all_text;
  my $untrimmed = $dom->all_text(0);

Extract text content from all descendant nodes of this element, smart
whitespace trimming is enabled by default.

  # "foo bar baz"
  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->at('div')->all_text;

  # "foo\nbarbaz\n"
  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->at('div')->all_text(0);

=head2 ancestors

  my $collection = $dom->ancestors;
  my $collection = $dom->ancestors('div ~ p');

Find all ancestor elements of this node matching the CSS selector and return a
L<collection|/"COLLECTION METHODS"> containing these elements as L<DOM::Tiny>
objects. All selectors listed in L</"SELECTORS"> are supported.

  # List tag names of ancestor elements
  say $dom->ancestors->map('tag')->join("\n");

=head2 append

  $dom = $dom->append('<p>I ♥ DOM::Tiny!</p>');

Append HTML/XML fragment to this node.

  # "<div><h1>Test</h1><h2>123</h2></div>"
  $dom->parse('<div><h1>Test</h1></div>')
    ->at('h1')->append('<h2>123</h2>')->root;

  # "<p>Test 123</p>"
  $dom->parse('<p>Test</p>')->at('p')
    ->child_nodes->first->append(' 123')->root;

=head2 append_content

  $dom = $dom->append_content('<p>I ♥ DOM::Tiny!</p>');

Append HTML/XML fragment (for C<root> and C<tag> nodes) or raw content to this
node's content.

  # "<div><h1>Test123</h1></div>"
  $dom->parse('<div><h1>Test</h1></div>')
    ->at('h1')->append_content('123')->root;

  # "<!-- Test 123 --><br>"
  $dom->parse('<!-- Test --><br>')
    ->child_nodes->first->append_content('123 ')->root;

  # "<p>Test<i>123</i></p>"
  $dom->parse('<p>Test</p>')->at('p')->append_content('<i>123</i>')->root;

=head2 at

  my $result = $dom->at('div ~ p');

Find first descendant element of this element matching the CSS selector and
return it as a L<DOM::Tiny> object or return C<undef> if none could be found.
All selectors listed in L</"SELECTORS"> are supported.

  # Find first element with "svg" namespace definition
  my $namespace = $dom->at('[xmlns\:svg]')->{'xmlns:svg'};

=head2 attr

  my $hash = $dom->attr;
  my $foo  = $dom->attr('foo');
  $dom     = $dom->attr({foo => 'bar'});
  $dom     = $dom->attr(foo => 'bar');

This element's attributes.

  # Remove an attribute
  delete $dom->attr->{id};

  # Attribute without value
  $dom->attr(selected => undef);

  # List id attributes
  say $dom->find('*')->map(attr => 'id')->compact->join("\n");

=head2 child_nodes

  my $collection = $dom->child_nodes;

Return a L<collection|/"COLLECTION METHODS"> containing all child nodes of this
element as L<DOM::Tiny> objects.

  # "<p><b>123</b></p>"
  $dom->parse('<p>Test<b>123</b></p>')->at('p')->child_nodes->first->remove;

  # "<!DOCTYPE html>"
  $dom->parse('<!DOCTYPE html><b>123</b>')->child_nodes->first;

  # " Test "
  $dom->parse('<b>123</b><!-- Test -->')->child_nodes->last->content;

=head2 children

  my $collection = $dom->children;
  my $collection = $dom->children('div ~ p');

Find all child elements of this element matching the CSS selector and return a
L<collection|/"COLLECTION METHODS"> containing these elements as L<DOM::Tiny>
objects. All selectors listed in L</"SELECTORS"> are supported.

  # Show tag name of random child element
  say $dom->children->shuffle->first->tag;

=head2 content

  my $str = $dom->content;
  $dom    = $dom->content('<p>I ♥ DOM::Tiny!</p>');

Return this node's content or replace it with HTML/XML fragment (for C<root>
and C<tag> nodes) or raw content.

  # "<b>Test</b>"
  $dom->parse('<div><b>Test</b></div>')->at('div')->content;

  # "<div><h1>123</h1></div>"
  $dom->parse('<div><h1>Test</h1></div>')->at('h1')->content('123')->root;

  # "<p><i>123</i></p>"
  $dom->parse('<p>Test</p>')->at('p')->content('<i>123</i>')->root;

  # "<div><h1></h1></div>"
  $dom->parse('<div><h1>Test</h1></div>')->at('h1')->content('')->root;

  # " Test "
  $dom->parse('<!-- Test --><br>')->child_nodes->first->content;

  # "<div><!-- 123 -->456</div>"
  $dom->parse('<div><!-- Test -->456</div>')
    ->at('div')->child_nodes->first->content(' 123 ')->root;

=head2 descendant_nodes

  my $collection = $dom->descendant_nodes;

Return a L<collection|/"COLLECTION METHODS"> containing all descendant nodes of
this element as L<DOM::Tiny> objects.

  # "<p><b>123</b></p>"
  $dom->parse('<p><!-- Test --><b>123<!-- 456 --></b></p>')
    ->descendant_nodes->grep(sub { $_->type eq 'comment' })
    ->map('remove')->first;

  # "<p><b>test</b>test</p>"
  $dom->parse('<p><b>123</b>456</p>')
    ->at('p')->descendant_nodes->grep(sub { $_->type eq 'text' })
    ->map(content => 'test')->first->root;

=head2 find

  my $collection = $dom->find('div ~ p');

Find all descendant elements of this element matching the CSS selector and
return a L<collection|/"COLLECTION METHODS"> containing these elements as
L<DOM::Tiny> objects. All selectors listed in L</"SELECTORS"> are supported.

  # Find a specific element and extract information
  my $id = $dom->find('div')->[23]{id};

  # Extract information from multiple elements
  my @headers = $dom->find('h1, h2, h3')->map('text')->each;

  # Count all the different tags
  my $hash = $dom->find('*')->reduce(sub { $a->{$b->tag}++; $a }, {});

  # Find elements with a class that contains dots
  my @divs = $dom->find('div.foo\.bar')->each;

=head2 following

  my $collection = $dom->following;
  my $collection = $dom->following('div ~ p');

Find all sibling elements after this node matching the CSS selector and return
a L<collection|/"COLLECTION METHODS"> containing these elements as L<DOM::Tiny>
objects. All selectors listen in L</"SELECTORS"> are supported.

  # List tags of sibling elements after this node
  say $dom->following->map('tag')->join("\n");

=head2 following_nodes

  my $collection = $dom->following_nodes;

Return a L<collection|/"COLLECTION METHODS"> containing all sibling nodes after
this node as L<DOM::Tiny> objects.

  # "C"
  $dom->parse('<p>A</p><!-- B -->C')->at('p')->following_nodes->last->content;

=head2 matches

  my $bool = $dom->matches('div ~ p');

Check if this element matches the CSS selector. All selectors listed in
L</"SELECTORS"> are supported.

  # True
  $dom->parse('<p class="a">A</p>')->at('p')->matches('.a');
  $dom->parse('<p class="a">A</p>')->at('p')->matches('p[class]');

  # False
  $dom->parse('<p class="a">A</p>')->at('p')->matches('.b');
  $dom->parse('<p class="a">A</p>')->at('p')->matches('p[id]');

=head2 namespace

  my $namespace = $dom->namespace;

Find this element's namespace or return C<undef> if none could be found.

  # Find namespace for an element with namespace prefix
  my $namespace = $dom->at('svg > svg\:circle')->namespace;

  # Find namespace for an element that may or may not have a namespace prefix
  my $namespace = $dom->at('svg > circle')->namespace;

=head2 next

  my $sibling = $dom->next;

Return L<DOM::Tiny> object for next sibling element or C<undef> if there are no
more siblings.

  # "<h2>123</h2>"
  $dom->parse('<div><h1>Test</h1><h2>123</h2></div>')->at('h1')->next;

=head2 next_node

  my $sibling = $dom->next_node;

Return L<DOM::Tiny> object for next sibling node or C<undef> if there are no
more siblings.

  # "456"
  $dom->parse('<p><b>123</b><!-- Test -->456</p>')
    ->at('b')->next_node->next_node;

  # " Test "
  $dom->parse('<p><b>123</b><!-- Test -->456</p>')
    ->at('b')->next_node->content;

=head2 parent

  my $parent = $dom->parent;

Return L<DOM::Tiny> object for parent of this node or C<undef> if this node has
no parent.

=head2 parse

  $dom = $dom->parse('<foo bar="baz">I ♥ DOM::Tiny!</foo>');

Parse HTML/XML fragment.

  # Parse XML
  my $dom = DOM::Tiny->new->xml(1)->parse($xml);

=head2 preceding

  my $collection = $dom->preceding;
  my $collection = $dom->preceding('div ~ p');

Find all sibling elements before this node matching the CSS selector and return
a L<collection|/"COLLECTION METHODS"> containing these elements as L<DOM::Tiny>
objects. All selectors listed in L</"SELECTORS"> are supported.

  # List tags of sibling elements before this node
  say $dom->preceding->map('tag')->join("\n");

=head2 preceding_nodes

  my $collection = $dom->preceding_nodes;

Return a L<collection|/"COLLECTION METHODS"> containing all sibling nodes
before this node as L<DOM::Tiny> objects.

  # "A"
  $dom->parse('A<!-- B --><p>C</p>')->at('p')->preceding_nodes->first->content;

=head2 prepend

  $dom = $dom->prepend('<p>I ♥ DOM::Tiny!</p>');

Prepend HTML/XML fragment to this node.

  # "<div><h1>Test</h1><h2>123</h2></div>"
  $dom->parse('<div><h2>123</h2></div>')
    ->at('h2')->prepend('<h1>Test</h1>')->root;

  # "<p>Test 123</p>"
  $dom->parse('<p>123</p>')
    ->at('p')->child_nodes->first->prepend('Test ')->root;

=head2 prepend_content

  $dom = $dom->prepend_content('<p>I ♥ DOM::Tiny!</p>');

Prepend HTML/XML fragment (for C<root> and C<tag> nodes) or raw content to this
node's content.

  # "<div><h2>Test123</h2></div>"
  $dom->parse('<div><h2>123</h2></div>')
    ->at('h2')->prepend_content('Test')->root;

  # "<!-- Test 123 --><br>"
  $dom->parse('<!-- 123 --><br>')
    ->child_nodes->first->prepend_content(' Test')->root;

  # "<p><i>123</i>Test</p>"
  $dom->parse('<p>Test</p>')->at('p')->prepend_content('<i>123</i>')->root;

=head2 previous

  my $sibling = $dom->previous;

Return L<DOM::Tiny> object for previous sibling element or C<undef> if there
are no more siblings.

  # "<h1>Test</h1>"
  $dom->parse('<div><h1>Test</h1><h2>123</h2></div>')->at('h2')->previous;

=head2 previous_node

  my $sibling = $dom->previous_node;

Return L<DOM::Tiny> object for previous sibling node or C<undef> if there are
no more siblings.

  # "123"
  $dom->parse('<p>123<!-- Test --><b>456</b></p>')
    ->at('b')->previous_node->previous_node;

  # " Test "
  $dom->parse('<p>123<!-- Test --><b>456</b></p>')
    ->at('b')->previous_node->content;

=head2 remove

  my $parent = $dom->remove;

Remove this node and return L</"root"> (for C<root> nodes) or L</"parent">.

  # "<div></div>"
  $dom->parse('<div><h1>Test</h1></div>')->at('h1')->remove;

  # "<p><b>456</b></p>"
  $dom->parse('<p>123<b>456</b></p>')
    ->at('p')->child_nodes->first->remove->root;

=head2 replace

  my $parent = $dom->replace('<div>I ♥ DOM::Tiny!</div>');

Replace this node with HTML/XML fragment and return L</"root"> (for C<root>
nodes) or L</"parent">.

  # "<div><h2>123</h2></div>"
  $dom->parse('<div><h1>Test</h1></div>')->at('h1')->replace('<h2>123</h2>');

  # "<p><b>123</b></p>"
  $dom->parse('<p>Test</p>')
    ->at('p')->child_nodes->[0]->replace('<b>123</b>')->root;

=head2 root

  my $root = $dom->root;

Return L<DOM::Tiny> object for C<root> node.

=head2 strip

  my $parent = $dom->strip;

Remove this element while preserving its content and return L</"parent">.

  # "<div>Test</div>"
  $dom->parse('<div><h1>Test</h1></div>')->at('h1')->strip;

=head2 tag

  my $tag = $dom->tag;
  $dom    = $dom->tag('div');

This element's tag name.

  # List tag names of child elements
  say $dom->children->map('tag')->join("\n");

=head2 tap

  $dom = $dom->tap(sub {...});

Equivalent to L<Mojo::Base/"tap">.

=head2 text

  my $trimmed   = $dom->text;
  my $untrimmed = $dom->text(0);

Extract text content from this element only (not including child elements),
smart whitespace trimming is enabled by default.

  # "foo baz"
  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->at('div')->text;

  # "foo\nbaz\n"
  $dom->parse("<div>foo\n<p>bar</p>baz\n</div>")->at('div')->text(0);

=head2 to_string

  my $str = $dom->to_string;

Render this node and its content to HTML/XML.

  # "<b>Test</b>"
  $dom->parse('<div><b>Test</b></div>')->at('div b')->to_string;

=head2 tree

  my $tree = $dom->tree;
  $dom     = $dom->tree(['root']);

Document Object Model. Note that this structure should only be used very
carefully since it is very dynamic.

=head2 type

  my $type = $dom->type;

This node's type, usually C<cdata>, C<comment>, C<doctype>, C<pi>, C<raw>,
C<root>, C<tag> or C<text>.

  # "cdata"
  $dom->parse('<![CDATA[Test]]>')->child_nodes->first->type;

  # "comment"
  $dom->parse('<!-- Test -->')->child_nodes->first->type;

  # "doctype"
  $dom->parse('<!DOCTYPE html>')->child_nodes->first->type;

  # "pi"
  $dom->parse('<?xml version="1.0"?>')->child_nodes->first->type;

  # "raw"
  $dom->parse('<title>Test</title>')->at('title')->child_nodes->first->type;

  # "root"
  $dom->parse('<p>Test</p>')->type;

  # "tag"
  $dom->parse('<p>Test</p>')->at('p')->type;

  # "text"
  $dom->parse('<p>Test</p>')->at('p')->child_nodes->first->type;

=head2 val

  my $value = $dom->val;

Extract value from form element (such as C<button>, C<input>, C<option>,
C<select> and C<textarea>) or return C<undef> if this element has no value. In
the case of C<select> with C<multiple> attribute, find C<option> elements with
C<selected> attribute and return an array reference with all values or C<undef>
if none could be found.

  # "a"
  $dom->parse('<input name="test" value="a">')->at('input')->val;

  # "b"
  $dom->parse('<textarea>b</textarea>')->at('textarea')->val;

  # "c"
  $dom->parse('<option value="c">Test</option>')->at('option')->val;

  # "d"
  $dom->parse('<select><option selected>d</option></select>')
    ->at('select')->val;

  # "e"
  $dom->parse('<select multiple><option selected>e</option></select>')
    ->at('select')->val->[0];

=head2 wrap

  $dom = $dom->wrap('<div></div>');

Wrap HTML/XML fragment around this node, placing it as the last child of the
first innermost element.

  # "<p>123<b>Test</b></p>"
  $dom->parse('<b>Test</b>')->at('b')->wrap('<p>123</p>')->root;

  # "<div><p><b>Test</b></p>123</div>"
  $dom->parse('<b>Test</b>')->at('b')->wrap('<div><p></p>123</div>')->root;

  # "<p><b>Test</b></p><p>123</p>"
  $dom->parse('<b>Test</b>')->at('b')->wrap('<p></p><p>123</p>')->root;

  # "<p><b>Test</b></p>"
  $dom->parse('<p>Test</p>')->at('p')->child_nodes->first->wrap('<b>')->root;

=head2 wrap_content

  $dom = $dom->wrap_content('<div></div>');

Wrap HTML/XML fragment around this node's content, placing it as the last
children of the first innermost element.

  # "<p><b>123Test</b></p>"
  $dom->parse('<p>Test<p>')->at('p')->wrap_content('<b>123</b>')->root;

  # "<p><b>Test</b></p><p>123</p>"
  $dom->parse('<b>Test</b>')->wrap_content('<p></p><p>123</p>');

=head2 xml

  my $bool = $dom->xml;
  $dom     = $dom->xml($bool);

Disable HTML semantics in parser and activate case-sensitivity, defaults to
auto detection based on processing instructions.

=head1 COLLECTION METHODS

Some L<DOM::Tiny> methods return an array-based collection object based on
L<Mojo::Collection>, which can either be accessed directly as an array
reference, or with the following methods.

  # Chain methods
  $collection->map(sub { ucfirst })->shuffle->each(sub {
    my ($word, $num) = @_;
    say "$num: $word";
  });

  # Access array directly to manipulate collection
  $collection->[23] += 100;
  say for @$collection;

=head2 compact

  my $new = $collection->compact;

Create a new collection with all elements that are defined and not an empty
string.

  # $collection contains (0, 1, undef, 2, '', 3)
  $collection->compact->join(', '); # "0, 1, 2, 3"

=head2 each

  my @elements = $collection->each;
  $collection  = $collection->each(sub {...});

Evaluate callback for each element in collection or return all elements as a
list if none has been provided. The element will be the first argument passed
to the callback and is also available as C<$_>.

  # Make a numbered list
  $collection->each(sub {
    my ($e, $num) = @_;
    say "$num: $e";
  });

=head2 first

  my $first = $collection->first;
  my $first = $collection->first(qr/foo/);
  my $first = $collection->first(sub {...});
  my $first = $collection->first($method);
  my $first = $collection->first($method, @args);

Evaluate regular expression/callback for, or call method on, each element in
collection and return the first one that matched the regular expression, or for
which the callback/method returned true. The element will be the first argument
passed to the callback and is also available as C<$_>.

  # Longer version
  my $first = $collection->first(sub { $_->$method(@args) });

  # Find first value that contains the word "dom"
  my $interesting = $collection->first(qr/dom/i);

  # Find first value that is greater than 5
  my $greater = $collection->first(sub { $_ > 5 });

=head2 flatten

  my $new = $collection->flatten;

Flatten nested collections/arrays recursively and create a new collection with
all elements.

  # $collection contains (1, [2, [3, 4], 5, [6]], 7)
  $collection->flatten->join(', '); # "1, 2, 3, 4, 5, 6, 7"

=head2 grep

  my $new = $collection->grep(qr/foo/);
  my $new = $collection->grep(sub {...});
  my $new = $collection->grep($method);
  my $new = $collection->grep($method, @args);

Evaluate regular expression/callback for, or call method on, each element in
collection and create a new collection with all elements that matched the
regular expression, or for which the callback/method returned true. The element
will be the first argument passed to the callback and is also available as
C<$_>.

  # Longer version
  my $new = $collection->grep(sub { $_->$method(@args) });

  # Find all values that contain the word "dom"
  my $interesting = $collection->grep(qr/dom/i);

  # Find all values that are greater than 5
  my $greater = $collection->grep(sub { $_ > 5 });

=head2 join

  my $stream = $collection->join;
  my $stream = $collection->join("\n");

Turn collection into string.

  # Join all values with commas
  $collection->join(', ');

=head2 last

  my $last = $collection->last;

Return the last element in collection.

=head2 map

  my $new = $collection->map(sub {...});
  my $new = $collection->map($method);
  my $new = $collection->map($method, @args);

Evaluate callback for, or call method on, each element in collection and create
a new collection from the results. The element will be the first argument
passed to the callback and is also available as C<$_>.

  # Longer version
  my $new = $collection->map(sub { $_->$method(@args) });

  # Append the word "dom" to all values
  my $domified = $collection->map(sub { $_ . 'dom' });

=head2 reduce

  my $result = $collection->reduce(sub {...});
  my $result = $collection->reduce(sub {...}, $initial);

Reduce elements in collection with callback, the first element will be used as
initial value if none has been provided.

  # Calculate the sum of all values
  my $sum = $collection->reduce(sub { $a + $b });

  # Count how often each value occurs in collection
  my $hash = $collection->reduce(sub { $a->{$b}++; $a }, {});

=head2 reverse

  my $new = $collection->reverse;

Create a new collection with all elements in reverse order.

=head2 slice

  my $new = $collection->slice(4 .. 7);

Create a new collection with all selected elements.

  # $collection contains ('A', 'B', 'C', 'D', 'E')
  $collection->slice(1, 2, 4)->join(' '); # "B C E"

=head2 shuffle

  my $new = $collection->shuffle;

Create a new collection with all elements in random order.

=head2 size

  my $size = $collection->size;

Number of elements in collection.

=head2 sort

  my $new = $collection->sort;
  my $new = $collection->sort(sub {...});

Sort elements based on return value of callback and create a new collection
from the results.

  # Sort values case-insensitive
  my $case_insensitive = $collection->sort(sub { uc($a) cmp uc($b) });

=head2 tap

  $collection = $collection->tap(sub {...});

Equivalent to L<Mojo::Base/"tap">.

=head2 to_array

  my $array = $collection->to_array;

Turn collection into array reference.

=head2 uniq

  my $new = $collection->uniq;
  my $new = $collection->uniq(sub {...});
  my $new = $collection->uniq($method);
  my $new = $collection->uniq($method, @args);

Create a new collection without duplicate elements, using the string
representation of either the elements or the return value of the
callback/method.

  # Longer version
  my $new = $collection->uniq(sub { $_->$method(@args) });

  # $collection contains ('foo', 'bar', 'bar', 'baz')
  $collection->uniq->join(' '); # "foo bar baz"

  # $collection contains ([1, 2], [2, 1], [3, 2])
  $collection->uniq(sub{ $_->[1] })->to_array; # "[[1, 2], [2, 1]]"

=head1 SELECTORS

L<DOM::Tiny> uses a CSS selector engine based on L<Mojo::DOM::CSS>. All CSS
selectors that make sense for a standalone parser are supported.

=head2 *

Any element.

  my $all = $dom->find('*');

=head2 E

An element of type C<E>.

  my $title = $dom->at('title');

=head2 E[foo]

An C<E> element with a C<foo> attribute.

  my $links = $dom->find('a[href]');

=head2 E[foo="bar"]

An C<E> element whose C<foo> attribute value is exactly equal to C<bar>.

  my $case_sensitive = $dom->find('input[type="hidden"]');
  my $case_sensitive = $dom->find('input[type=hidden]');

=head2 E[foo="bar" i]

An C<E> element whose C<foo> attribute value is exactly equal to any
(ASCII-range) case-permutation of C<bar>. Note that this selector is
EXPERIMENTAL and might change without warning!

  my $case_insensitive = $dom->find('input[type="hidden" i]');
  my $case_insensitive = $dom->find('input[type=hidden i]');
  my $case_insensitive = $dom->find('input[class~="foo" i]');

This selector is part of
L<Selectors Level 4|http://dev.w3.org/csswg/selectors-4>, which is still a work
in progress.

=head2 E[foo~="bar"]

An C<E> element whose C<foo> attribute value is a list of whitespace-separated
values, one of which is exactly equal to C<bar>.

  my $foo = $dom->find('input[class~="foo"]');
  my $foo = $dom->find('input[class~=foo]');

=head2 E[foo^="bar"]

An C<E> element whose C<foo> attribute value begins exactly with the string
C<bar>.

  my $begins_with = $dom->find('input[name^="f"]');
  my $begins_with = $dom->find('input[name^=f]');

=head2 E[foo$="bar"]

An C<E> element whose C<foo> attribute value ends exactly with the string
C<bar>.

  my $ends_with = $dom->find('input[name$="o"]');
  my $ends_with = $dom->find('input[name$=o]');

=head2 E[foo*="bar"]

An C<E> element whose C<foo> attribute value contains the substring C<bar>.

  my $contains = $dom->find('input[name*="fo"]');
  my $contains = $dom->find('input[name*=fo]');

=head2 E:root

An C<E> element, root of the document.

  my $root = $dom->at(':root');

=head2 E:nth-child(n)

An C<E> element, the C<n-th> child of its parent.

  my $third = $dom->find('div:nth-child(3)');
  my $odd   = $dom->find('div:nth-child(odd)');
  my $even  = $dom->find('div:nth-child(even)');
  my $top3  = $dom->find('div:nth-child(-n+3)');

=head2 E:nth-last-child(n)

An C<E> element, the C<n-th> child of its parent, counting from the last one.

  my $third    = $dom->find('div:nth-last-child(3)');
  my $odd      = $dom->find('div:nth-last-child(odd)');
  my $even     = $dom->find('div:nth-last-child(even)');
  my $bottom3  = $dom->find('div:nth-last-child(-n+3)');

=head2 E:nth-of-type(n)

An C<E> element, the C<n-th> sibling of its type.

  my $third = $dom->find('div:nth-of-type(3)');
  my $odd   = $dom->find('div:nth-of-type(odd)');
  my $even  = $dom->find('div:nth-of-type(even)');
  my $top3  = $dom->find('div:nth-of-type(-n+3)');

=head2 E:nth-last-of-type(n)

An C<E> element, the C<n-th> sibling of its type, counting from the last one.

  my $third    = $dom->find('div:nth-last-of-type(3)');
  my $odd      = $dom->find('div:nth-last-of-type(odd)');
  my $even     = $dom->find('div:nth-last-of-type(even)');
  my $bottom3  = $dom->find('div:nth-last-of-type(-n+3)');

=head2 E:first-child

An C<E> element, first child of its parent.

  my $first = $dom->find('div p:first-child');

=head2 E:last-child

An C<E> element, last child of its parent.

  my $last = $dom->find('div p:last-child');

=head2 E:first-of-type

An C<E> element, first sibling of its type.

  my $first = $dom->find('div p:first-of-type');

=head2 E:last-of-type

An C<E> element, last sibling of its type.

  my $last = $dom->find('div p:last-of-type');

=head2 E:only-child

An C<E> element, only child of its parent.

  my $lonely = $dom->find('div p:only-child');

=head2 E:only-of-type

An C<E> element, only sibling of its type.

  my $lonely = $dom->find('div p:only-of-type');

=head2 E:empty

An C<E> element that has no children (including text nodes).

  my $empty = $dom->find(':empty');

=head2 E:checked

A user interface element C<E> which is checked (for instance a radio-button or
checkbox).

  my $input = $dom->find(':checked');

=head2 E.warning

An C<E> element whose class is "warning".

  my $warning = $dom->find('div.warning');

=head2 E#myid

An C<E> element with C<ID> equal to "myid".

  my $foo = $dom->at('div#foo');

=head2 E:not(s)

An C<E> element that does not match simple selector C<s>.

  my $others = $dom->find('div p:not(:first-child)');

=head2 E F

An C<F> element descendant of an C<E> element.

  my $headlines = $dom->find('div h1');

=head2 E E<gt> F

An C<F> element child of an C<E> element.

  my $headlines = $dom->find('html > body > div > h1');

=head2 E + F

An C<F> element immediately preceded by an C<E> element.

  my $second = $dom->find('h1 + h2');

=head2 E ~ F

An C<F> element preceded by an C<E> element.

  my $second = $dom->find('h1 ~ h2');

=head2 E, F, G

Elements of type C<E>, C<F> and C<G>.

  my $headlines = $dom->find('h1, h2, h3');

=head2 E[foo=bar][bar=baz]

An C<E> element whose attributes match all following attribute selectors.

  my $links = $dom->find('a[foo^=b][foo$=ar]');

=head1 BUGS

Report any issues on the public bugtracker.

=head1 AUTHOR

Dan Book <dbook@cpan.org>

=head1 COPYRIGHT AND LICENSE

This software is Copyright (c) 2015 by Dan Book.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)

=head1 SEE ALSO

L<Mojo::DOM>, L<XML::LibXML>, L<XML::Twig>, L<HTML::TreeBuilder>, L<XML::Smart>

=for Pod::Coverage TO_JSON

=cut