#NAME
Mojo::DOM::CSS - CSS selector engine
#SYNOPSIS
use Mojo::DOM::CSS;
# Select elements from DOM tree
my $css = Mojo::DOM::CSS->new(tree => $tree);
my $elements = $css->select('h1, h2, h3');
#DESCRIPTION
Mojo::DOM::CSS is the CSS selector engine used by Mojo::DOM, based on the HTML Living Standard and Selectors Level 3.
#SELECTORS
All CSS selectors that make sense for a standalone parser are supported.
#*
Any element.
my $all = $css->select('*');
#E
An element of type E
.
my $title = $css->select('title');
#E[foo]
An E
element with a foo
attribute.
my $links = $css->select('a[href]');
#E[foo="bar"]
An E
element whose foo
attribute value is exactly equal to bar
.
my $case_sensitive = $css->select('input[type="hidden"]');
my $case_sensitive = $css->select('input[type=hidden]');
#E[foo="bar" i]
An E
element whose foo
attribute value is exactly equal to any (ASCII-range) case-permutation of bar
. Note that this selector is EXPERIMENTAL and might change without warning!
my $case_insensitive = $css->select('input[type="hidden" i]');
my $case_insensitive = $css->select('input[type=hidden i]');
my $case_insensitive = $css->select('input[class~="foo" i]');
This selector is part of Selectors Level 4, which is still a work in progress.
#E[foo="bar" s]
An E
element whose foo
attribute value is exactly and case-sensitively equal to bar
. Note that this selector is EXPERIMENTAL and might change without warning!
my $case_sensitive = $css->select('input[type="hidden" s]');
This selector is part of Selectors Level 4, which is still a work in progress.
#E[foo~="bar"]
An E
element whose foo
attribute value is a list of whitespace-separated values, one of which is exactly equal to bar
.
my $foo = $css->select('input[class~="foo"]');
my $foo = $css->select('input[class~=foo]');
#E[foo^="bar"]
An E
element whose foo
attribute value begins exactly with the string bar
.
my $begins_with = $css->select('input[name^="f"]');
my $begins_with = $css->select('input[name^=f]');
#E[foo$="bar"]
An E
element whose foo
attribute value ends exactly with the string bar
.
my $ends_with = $css->select('input[name$="o"]');
my $ends_with = $css->select('input[name$=o]');
#E[foo*="bar"]
An E
element whose foo
attribute value contains the substring bar
.
my $contains = $css->select('input[name*="fo"]');
my $contains = $css->select('input[name*=fo]');
#E[foo|="en"]
An E
element whose foo
attribute has a hyphen-separated list of values beginning (from the left) with en
.
my $english = $css->select('link[hreflang|=en]');
#E:root
An E
element, root of the document.
my $root = $css->select(':root');
#E:nth-child(n)
An E
element, the n-th
child of its parent.
my $third = $css->select('div:nth-child(3)');
my $odd = $css->select('div:nth-child(odd)');
my $even = $css->select('div:nth-child(even)');
my $top3 = $css->select('div:nth-child(-n+3)');
#E:nth-last-child(n)
An E
element, the n-th
child of its parent, counting from the last one.
my $third = $css->select('div:nth-last-child(3)');
my $odd = $css->select('div:nth-last-child(odd)');
my $even = $css->select('div:nth-last-child(even)');
my $bottom3 = $css->select('div:nth-last-child(-n+3)');
#E:nth-of-type(n)
An E
element, the n-th
sibling of its type.
my $third = $css->select('div:nth-of-type(3)');
my $odd = $css->select('div:nth-of-type(odd)');
my $even = $css->select('div:nth-of-type(even)');
my $top3 = $css->select('div:nth-of-type(-n+3)');
#E:nth-last-of-type(n)
An E
element, the n-th
sibling of its type, counting from the last one.
my $third = $css->select('div:nth-last-of-type(3)');
my $odd = $css->select('div:nth-last-of-type(odd)');
my $even = $css->select('div:nth-last-of-type(even)');
my $bottom3 = $css->select('div:nth-last-of-type(-n+3)');
#E:first-child
An E
element, first child of its parent.
my $first = $css->select('div p:first-child');
#E:last-child
An E
element, last child of its parent.
my $last = $css->select('div p:last-child');
#E:first-of-type
An E
element, first sibling of its type.
my $first = $css->select('div p:first-of-type');
#E:last-of-type
An E
element, last sibling of its type.
my $last = $css->select('div p:last-of-type');
#E:only-child
An E
element, only child of its parent.
my $lonely = $css->select('div p:only-child');
#E:only-of-type
An E
element, only sibling of its type.
my $lonely = $css->select('div p:only-of-type');
#E:empty
An E
element that has no children (including text nodes).
my $empty = $css->select(':empty');
#E:any-link
Alias for "E:link". Note that this selector is EXPERIMENTAL and might change without warning! This selector is part of Selectors Level 4, which is still a work in progress.
#E:link
An E
element being the source anchor of a hyperlink of which the target is not yet visited (:link
) or already visited (:visited
). Note that Mojo::DOM::CSS is not stateful, therefore :any-link
, :link
and :visited
yield exactly the same results.
my $links = $css->select(':any-link');
my $links = $css->select(':link');
my $links = $css->select(':visited');
#E:visited
Alias for "E:link".
#E:scope
An E
element being a designated reference element. Note that this selector is EXPERIMENTAL and might change without warning!
my $scoped = $css->select('a:not(:scope > a)');
my $scoped = $css->select('div :scope p');
my $scoped = $css->select('~ p');
This selector is part of Selectors Level 4, which is still a work in progress.
#E:checked
A user interface element E
which is checked (for instance a radio-button or checkbox).
my $input = $css->select(':checked');
#E.warning
An E
element whose class is "warning".
my $warning = $css->select('div.warning');
#E#myid
An E
element with ID
equal to "myid".
my $foo = $css->select('div#foo');
#E:not(s1, s2)
An E
element that does not match either compound selector s1
or compound selector s2
. Note that support for compound selectors is EXPERIMENTAL and might change without warning!
my $others = $css->select('div p:not(:first-child, :last-child)');
Support for compound selectors was added as part of Selectors Level 4, which is still a work in progress.
#E:is(s1, s2)
An E
element that matches compound selector s1
and/or compound selector s2
. Note that this selector is EXPERIMENTAL and might change without warning!
my $headers = $css->select(':is(section, article, aside, nav) h1');
This selector is part of Selectors Level 4, which is still a work in progress.
#E:has(rs1, rs2)
An E
element, if either of the relative selectors rs1
or rs2
, when evaluated with E
as the :scope elements, match an element. Note that this selector is EXPERIMENTAL and might change without warning!
my $link = $css->select('a:has(> img)');
This selector is part of Selectors Level 4, which is still a work in progress. Also be aware that this feature is currently marked at-risk
, so there is a high chance that it will get removed completely.
#E:text(string_or_regex)
An E
element containing text content that substring matches string_or_regex
case-insensitively or that regex matches string_or_regex
. For regular expressions use the format :text(/.../)
. Note that this selector is EXPERIMENTAL and might change without warning!
# Substring match
my $login = $css->select(':text(Log in)');
# Regex match
my $login = $css->select(':text(/Log ?in/)');
# Regex match (case-insensitive)
my $login = $css->select(':text(/(?i:Log ?in)/)');
This is a custom selector for Mojo::DOM and not part of any spec.
#A|E
An E
element that belongs to the namespace alias A
from CSS Namespaces Module Level 3. Key/value pairs passed to selector methods are used to declare namespace aliases.
my $elem = $css->select('lq|elem', lq => 'http://example.com/q-markup');
Using an empty alias searches for an element that belongs to no namespace.
my $div = $c->select('|div');
#E F
An F
element descendant of an E
element.
my $headlines = $css->select('div h1');
#E > F
An F
element child of an E
element.
my $headlines = $css->select('html > body > div > h1');
#E + F
An F
element immediately preceded by an E
element.
my $second = $css->select('h1 + h2');
#E ~ F
An F
element preceded by an E
element.
my $second = $css->select('h1 ~ h2');
#E, F, G
Elements of type E
, F
and G
.
my $headlines = $css->select('h1, h2, h3');
#E[foo=bar][bar=baz]
An E
element whose attributes match all following attribute selectors.
my $links = $css->select('a[foo^=b][foo$=ar]');
#ATTRIBUTES
Mojo::DOM::CSS implements the following attributes.
#tree
my $tree = $css->tree;
$css = $css->tree(['root']);
Document Object Model. Note that this structure should only be used very carefully since it is very dynamic.
#METHODS
Mojo::DOM::CSS inherits all methods from Mojo::Base and implements the following new ones.
#matches
my $bool = $css->matches('head > title');
my $bool = $css->matches('svg|line', svg => 'http://www.w3.org/2000/svg');
Check if first node in "tree" matches the CSS selector. Trailing key/value pairs can be used to declare xml namespace aliases.
#select
my $results = $css->select('head > title');
my $results = $css->select('svg|line', svg => 'http://www.w3.org/2000/svg');
Run CSS selector against "tree". Trailing key/value pairs can be used to declare xml namespace aliases.
#select_one
my $result = $css->select_one('head > title');
my $result =
$css->select_one('svg|line', svg => 'http://www.w3.org/2000/svg');
Run CSS selector against "tree" and stop as soon as the first node matched. Trailing key/value pairs can be used to declare xml namespace aliases.
#DEBUGGING
You can set the MOJO_DOM_CSS_DEBUG
environment variable to get some advanced diagnostics information printed to STDERR
.
MOJO_DOM_CSS_DEBUG=1