SYNOPSIS
use Web::Query;
wq('http://www.w3.org/TR/html401/')
->find('div.head dt')
->each(sub {
my $i = shift;
printf("%d %s\n", $i+1, $_->text);
});
DESCRIPTION
Web::Query is a yet another scraping framework, have a jQuery like
interface.
Yes, I know Ingy's pQuery. But it's just a alpha quality. It doesn't
works. Web::Query built at top of the CPAN modules,
HTML::TreeBuilder::XPath, LWP::UserAgent, and HTML::Selector::XPath.
So, this module uses HTML::Selector::XPath and only supports the CSS 3
selector supported by that module. Web::Query doesn't support jQuery's
extended queries(yet?). If a selector is passed as a scalar ref, it'll
be taken as a straight XPath expression.
$wq( '
' )->find( 'p' ); # css selector
$wq( '' )->find( \'/div/p' ); # xpath selector
THIS LIBRARY IS UNDER DEVELOPMENT. ANY API MAY CHANGE WITHOUT NOTICE.
FUNCTIONS
wq($stuff)
This is a shortcut for Web::Query->new($stuff). This function is
exported by default.
METHODS
CONSTRUCTORS
my $q = Web::Query->new($stuff, \%options )
Create new instance of Web::Query. You can make the instance from
URL(http, https, file scheme), HTML in string, URL in string, URI
object, and instance of HTML::Element.
This method throw the exception on unknown $stuff.
This method returns undefined value on non-successful response with
URL.
Currently, the only two valid options are indent, which will be used
as the indentation string if the object is printed, and
no_space_compacting, which will prevent the compaction of whitespace
characters in text blocks.
my $q = Web::Query->new_from_element($element: HTML::Element)
Create new instance of Web::Query from instance of HTML::Element.
my $q = Web::Query->new_from_html($html: Str)
Create new instance of Web::Query from HTML.
my $q = Web::Query->new_from_url($url: Str)
Create new instance of Web::Query from URL.
If the response is not success(It means /^20[0-9]$/), this method
returns undefined value.
You can get a last result of response, use the $Web::Query::RESPONSE.
Here is a best practical code:
my $url = 'http://example.com/';
my $q = Web::Query->new_from_url($url)
or die "Cannot get a resource from $url: " . Web::Query->last_response()->status_line;
my $q = Web::Query->new_from_file($file_name: Str)
Create new instance of Web::Query from file name.
TRAVERSING
add
Returns a new object augmented with the new element(s).
add($html)
An HTML fragment to add to the set of matched elements.
add(@elements)
One or more @elements to add to the set of matched elements.
@elements that already are part of the set are not added a second
time.
my $group = $wq->find('#foo'); # collection has 1 element
$group = $group->add( '#bar', $wq ); # 2 elements
$group->add( '#foo', $wq ); # still 2 elements
add($wq)
An existing Web::Query object to add to the set of matched elements.
add($selector, $context)
$selector is a string representing a selector expression to find
additional elements to add to the set of matched elements.
$context is the point in the document at which the selector should
begin matching
contents
Get the immediate children of each element in the set of matched
elements, including text and comment nodes.
each
Visit each nodes. $i is a counter value, 0 origin. $elem is iteration
item. $_ is localized by $elem.
$q->each(sub { my ($i, $elem) = @_; ... })
end
Back to the before context like jQuery.
filter
Reduce the elements to those that pass the function's test.
$q->filter(sub { my ($i, $elem) = @_; ... })
find
Get the descendants of each element in the current set of matched
elements, filtered by a selector.
my $q2 = $q->find($selector); # $selector is a CSS3 selector.
NOTE If you want to match the element itself, use "filter".
INCOMPATIBLE CHANGE From v0.14 to v0.19 (inclusive) find() also matched
the element itself, which is not jQuery compatible. You can achieve
that result using filter(), add() and find():
my $wq = wq(''); # needed because we don't have a global document like jQuery does
print $wq->filter('.foo')->add($wq->find('.foo'))->as_html; # bar
first
Return the first matching element.
This method constructs a new Web::Query object from the first matching
element.
last
Return the last matching element.
This method constructs a new Web::Query object from the last matching
element.
not($selector)
Return all the elements not matching the $selector.
# $do_for_love will be every thing, except #that
my $do_for_love = $wq->find('thing')->not('#that');
and_back
Add the previous set of elements to the current one.
# get the h1 plus everything until the next h1
$wq->find('h1')->next_until('h1')->and_back;
map
Creates a new array with the results of calling a provided function on
every element.
$q->map(sub { my ($i, $elem) = @_; ... })
parent
Get the parent of each element in the current set of matched elements.
prev
Get the previous node of each element in the current set of matched
elements.
my $prev = $q->prev;
next
Get the next node of each element in the current set of matched
elements.
my $next = $q->next;
next_until( $selector )
Get all subsequent siblings, up to (but not including) the next node
matched $selector.
MANIPULATION
add_class
Adds the specified class(es) to each of the set of matched elements.
# add class 'foo' to elements
wq('
')->find('p')->add_class('foo');
toggle_class( @classes )
Toggles the given class or classes on each of the element. I.e., if the
element had the class, it'll be removed, and if it hadn't, it'll be
added.
Classes are toggled once, no matter how many times they appear in the
argument list.
$q->toggle_class( 'foo', 'foo', 'bar' );
# equivalent to
$q->toggle_class('foo')->toggle_class('bar');
# and not
$q->toggle_class('foo')->toggle_class('foo')->toggle_class('bar');
after
Insert content, specified by the parameter, after each element in the
set of matched elements.
wq('')->find('p')
->after('bar')
->end
->as_html; #
The content can be anything accepted by "new".
append
Insert content, specified by the parameter, to the end of each element
in the set of matched elements.
wq('')->append('foo
')->as_html; #
The content can be anything accepted by "new".
as_html
Return the elements associated with the object as strings. If called in
a scalar context, only return the string representation of the first
element.
attr
Get/set the attribute value in element.
In getter mode, it'll return either the values of the attribute for all
elements of the set, or only the first one depending of the calling
context.
my @values = $q->attr('style'); # style of all elements
my $first_value = $q->attr('style'); # style of first element
In setter mode, it'll set the attribute value for all elements, and
return back the original object for easy chaining.
$q->attr( 'alt' => 'a picture' )->find( ... );
id
Get/set the elements's id attribute.
In getter mode, it behaves just like attr().
In setter mode, it behaves like attr(), but with the following
exceptions.
If the attribute value is a scalar, it'll be only assigned to the first
element of the set (as ids are supposed to be unique), and the returned
object will only contain that first element.
my $first_element = $q->id('the_one');
It's possible to set the ids of all the elements by passing a sub to
id(). The sub is given the same arguments as for each(), and its return
value is taken to be the new id of the elements.
$q->id( sub { my $i = shift; 'foo_' . $i } );
name
Get/set the elements's 'name' attribute.
my $name = $q->name; # equivalent to $q->attr( 'name' );
$q->name( 'foo' ); # equivalent to $q->attr( name => 'foo' );
data
Get/set the elements's 'data-*name*' attributes.
my $data = $q->data('foo'); # equivalent to $q->attr( 'data-foo' );
$q->data( 'foo' => 'bar' ); # equivalent to $q->attr( 'data-foo' => 'bar' );
tagname
Get/Set the tag name of elements.
my $name = $q->tagname;
$q->tagname($new_name);
before
Insert content, specified by the parameter, before each element in the
set of matched elements.
wq('')->find('p')
->before('bar')
->end
->as_html; #
The content can be anything accepted by "new".
clone
Create a deep copy of the set of matched elements.
detach
Remove the set of matched elements from the DOM.
has_class
Determine whether any of the matched elements are assigned the given
class.
html
Get/Set the innerHTML.
my @html = $q->html();
my $html = $q->html(); # 1st matching element only
$q->html('foo
');
insert_before
Insert every element in the set of matched elements before the target.
insert_after
Insert every element in the set of matched elements after the target.
prepend
Insert content, specified by the parameter, to the beginning of each
element in the set of matched elements.
remove
Delete the elements associated with the object from the DOM.
# remove all