package XML::Loy;
use Mojo::ByteStream 'b';
use Mojo::Loader qw/load_class/;
use Carp qw/croak carp/;
use Scalar::Util qw/blessed weaken/;
use Mojo::Base 'Mojo::DOM';
our $VERSION = '0.45';
sub DESTROY;
# Todo:
# - Add ->clone
# (Maybe via JSON serialisation of ->tree or using Storable or Dumper)
#
# Maybe necessary: *AUTOLOAD = \&XML::Loy::AUTOLOAD;
#
# - sub try_further { };
# # usage:
# sub author {
# return $autor or $self->try_further;
# };
#
# - ALERT!
# Do not allow for namespace islands
# Search $obj->find('* *[xmlns]') and change prefixing
# After ->SUPER::new;
# Or:
# Do allow for namespace islands and check for the
# namespace to add instead of the package name before
# prefixing.
#
# - set() should really try to overwrite.
#
# - add() with -before => '' and -after => ''
# - maybe possible to save to element
# - Maybe with small changes a change to the object
# (encoding, xml etc.) can be done
#
# - closest() (jQuery)
our @CARP_NOT;
# Import routine, run when calling the class properly
sub import {
my $class = shift;
return unless my $flag = shift;
if ($flag =~ /^-?(?i:base|with)$/) {
# Allow for manipulating the symbol table
no strict 'refs';
no warnings 'once';
# The caller is the calling (inheriting) class
my $caller = caller;
push @{"${caller}::ISA"}, __PACKAGE__;
if (@_) {
# Get class variables
my %param = @_;
# Set class variables
foreach (qw/namespace prefix mime/) {
if (exists $param{$_}) {
${ "${caller}::" . uc $_ } = delete $param{$_};
};
};
# Set class hook
if (exists $param{on_init}) {
*{"${caller}::ON_INIT"} = delete $param{on_init};
};
};
};
# Make inheriting classes strict and modern
strict->import;
warnings->import;
utf8->import;
feature->import(':5.10');
};
# Return class variables
{
no strict 'refs';
sub _namespace { ${"${_[0]}::NAMESPACE"} || '' };
sub _prefix { ${"${_[0]}::PREFIX"} || '' };
sub mime {
${ (blessed $_[0] || $_[0]) . '::MIME'} || 'application/xml'
};
sub _on_init {
my $class = shift;
my $self = $class;
# Run object method
if (blessed $class) {
$class = blessed $class;
}
# Run class method
else {
$self = shift;
};
# Run init hook
if ($class->can('ON_INIT')) {
*{"${class}::ON_INIT"}->($self) ;
};
};
};
# Construct new XML::Loy object
sub new {
my $class = shift;
my $self;
# Create from parent class
# Empty constructor
unless ($_[0]) {
$self = $class->SUPER::new->xml(1);
}
# XML::Loy object
elsif (ref $_[0]) {
$self = $class->SUPER::new(@_)->xml(1);
}
# XML string
elsif (index($_[0],'<') >= 0 || index($_[0],' ') >= 0) {
$self = $class->SUPER::new->xml(1)->parse(@_);
}
# Create a new node
else {
my $name = shift;
my $att = ref( $_[0] ) eq 'HASH' ? shift : +{};
my ($text, $comment) = @_;
$att->{'xmlns:loy'} = 'http://sojolicio.us/ns/xml-loy';
# Transform special attributes
_special_attributes($att) if $att;
# Create root
my $tree = [
'root',
[ pi => 'xml version="1.0" encoding="UTF-8" standalone="yes"']
];
# Add comment if given
push(@$tree, [ comment => $comment ]) if $comment;
# Create Tag element
my $element = [ tag => $name, $att, $tree ];
# Add element
push(@$tree, $element);
# Add text if given
push(@$element, [ text => $text ]) if defined $text;
# Create root element by parent class
$self = $class->SUPER::new->xml(1);
# Add newly created tree
$self->tree($tree);
# The class is derived
if ($class ne __PACKAGE__) {
# Set namespace if given
if (my $ns = $class->_namespace) {
$att->{xmlns} = $ns;
};
};
};
# Start init hook
$self->_on_init;
# Return root node
return $self;
};
# Append a new child node to the XML Node
sub add {
my $self = shift;
# Store tag
my $tag = $_[0];
# If node is root, use first element
if (!$self->parent &&
ref($self->tree->[1]) &&
ref($self->tree->[1]) eq 'ARRAY' &&
$self->tree->[1]->[0] eq 'pi') {
$self = $self->at('*');
};
# Add element
my $element = $self->_add_clean(@_) or return;
my $tree = $element->tree;
# Prepend with no prefix
if (index($tag, '-') == 0) {
$tree->[1] = substr($tag, 1);
return $element;
};
# Element is no tag
return $element unless $tree->[0] eq 'tag';
# Prepend prefix if necessary
my $caller = caller;
my $class = ref $self;
# Caller and class are not the same
if ($caller ne $class && $caller->can('_prefix')) {
if ((my $prefix = $caller->_prefix) && $caller->_namespace) {
$element->tree->[1] = "${prefix}:$tag";
};
};
# Return element
return $element;
};
# Append a child only once to the XML node.
sub set {
my $self = shift;
my $tag;
# If node is root, use first element
if (!$self->parent && $self->tree->[1]->[0] eq 'pi') {
$self = $self->at('*');
};
# Get tag from document object
if (ref $_[0]) {
$tag = $_[0]->at('*')->tag;
}
# Get tag
else {
# Store tag
$tag = shift;
# No prefix
if (index($tag, '-') == 0) {
$tag = substr($tag, 1);
}
# Maybe prefix
else {
# Prepend prefix if necessary
my $caller = caller;
my $class = ref $self;
# Caller and class are not the same
if ($caller ne $class && $caller->can('_prefix')) {
if ((my $prefix = $caller->_prefix) && $caller->_namespace) {
$tag = "${prefix}:$tag";
};
};
};
};
my $att = $self->tree->[2];
# Introduce attribute 'once'
$att->{'loy:once'} //= '';
# Check if set to once
if (index($att->{'loy:once'}, "($tag)") >= 0) {
# Todo: Maybe escaping - check in extensions
$self->children("$tag")->map('remove');
}
# Set if not already set
else {
$att->{'loy:once'} .= "($tag)";
};
# Add a ref, not the tag
unshift(@_, $tag) unless blessed $_[0];
# Add element (Maybe prefixed)
return $self->_add_clean(@_);
};
# Children of the node
sub children {
my ($self, $type) = @_;
# This method is a modified version of
# the children method of Mojo::DOM
# It works as written in the documentation,
# but is also aware of namespace prefixes.
# If node is root, use first element
if (!$self->parent &&
ref($self->tree->[1]) &&
ref($self->tree->[1]) eq 'ARRAY' &&
$self->tree->[1]->[0] eq 'pi') {
$self = $self->at('*');
};
my @children;
my $xml = $self->xml;
my $tree = $self->tree;
my $type_l = $type ? length $type : 0;
for my $e (@$tree[($tree->[0] eq 'root' ? 1 : 4) .. $#$tree]) {
# Make sure child is the right type
next unless $e->[0] eq 'tag';
# Type is given
if (defined $type) {
# Type is already prefixed or element is not prefixed
if (index($type, ':') > 0 || index($e->[1], ':') < 0) {
next if $e->[1] ne $type;
}
# Check, if type is valid, and ignore prefixes, cause tag is prefixed
elsif (index($e->[1], ':') > 0) {
next if substr($e->[1], (index($e->[1], ':') + 1)) ne $type;
};
};
push(@children, $self->new->tree($e)->xml($xml));
}
# Create new Mojo::Collection
return Mojo::Collection->new( @children );
};
# Append a new child node to the XML Node
sub _add_clean {
my $self = shift;
# Node is a node object
if (ref $_[0]) {
# Serialize node
my $node = $self->SUPER::new->xml(1)->tree( shift->tree );
# Get root attributes
my $root_attr = $node->_root_element->[2];
# Push namespaces to new root
foreach ( grep( index($_, 'xmlns:') == 0, keys %$root_attr ) ) {
# Strip xmlns prefix
$_ = substr($_, 6);
# Add namespace
$self->namespace( $_ => delete $root_attr->{ "xmlns:$_" } );
};
# Delete namespace information, if already set
if (exists $root_attr->{xmlns}) {
# Namespace information can be deleted
if (my $ns = $self->namespace) {
delete $root_attr->{xmlns} if $root_attr->{xmlns} eq $ns;
};
};
# Get root of parent node
my $base_root_attr = $self->_root_element->[2];
# Copy extensions
if (exists $root_attr->{'loy:ext'}) {
my $ext = $base_root_attr->{'loy:ext'};
$base_root_attr->{'loy:ext'} =
join('; ', $ext, split(/;\s/, delete $root_attr->{'loy:ext'}));
};
# Delete pi from node
my $sec = $node->tree->[1];
if (ref $sec eq 'ARRAY' && $sec->[0] eq 'pi') {
splice( @{ $node->tree }, 1,1 );
};
# Append new node
$self->append_content($node);
# Return first child
return $self->children->[-1];
}
# Node is a string
else {
my $name = shift;
# Pretty sloppy check for valid names
return unless $name =~ m!^-?[^\s<>]+$!;
my $att = shift if ref( $_[0] ) eq 'HASH';
my ($text, $comment) = @_;
# Node content with text
my $string = "<$name";
if (defined $text) {
$string .= '>' . b($text)->trim->xml_escape . "</$name>";
}
# Empty element
else {
$string .= ' />';
};
# Append new node
$self->append_content( $string );
# Get first child
my $node = $self->children->[-1];
# Attributes were given
if ($att) {
# Transform special attributes
_special_attributes($att);
# Add attributes to node
$node->attr($att);
};
# Add comment
$node->comment($comment) if $comment;
return $node;
};
};
# Transform special attributes
sub _special_attributes {
my $att = shift;
foreach ( grep { index($_, '-') == 0 } keys %$att ) {
# Set special attribute
$att->{'loy:' . substr($_, 1) } = lc delete $att->{$_};
};
};
# Prepend a comment to the XML node
sub comment {
my $self = shift;
my $parent;
# If node is root, use first element
return $self unless $parent = $self->parent;
# Find previous sibling
my $previous;
# Find previous node
for my $e (@{$parent->tree}) {
last if $e eq $self->tree;
$previous = $e;
};
# Trim and encode comment text
my $comment_text = b( shift )->trim->xml_escape;
# Add to previous comment
if ($previous && $previous->[0] eq 'comment') {
$previous->[1] .= '; ' . $comment_text;
}
# Create new comment node
else {
$self->prepend("<!--$comment_text-->");
};
# Return node
return $self;
};
# Add extension to document
sub extension {
my $self = shift;
# Get root element
my $root = $self->_root_element;
# No root to associate extension to
unless ($root) {
carp 'There is no document to associate the extension with';
return;
};
# Get ext string
my @ext = split(/;\s/, $root->[2]->{'loy:ext'} || '');
return @ext unless $_[0];
# New Loader
# my $loader = Mojo::Loader->new;
# Try all given extension names
while (my $ext = shift( @_ )) {
next if grep { $ext eq $_ } @ext;
# Default 'XML::Loy::' prefix
if (index($ext, '-') == 0) {
$ext =~ s/^-/XML::Loy::/;
};
# Unable to load extension
if (my $e = load_class $ext) {
carp "Exception: $e" if ref $e;
carp qq{Unable to load extension "$ext"};
next;
};
# Add extension to extensions list
push(@ext, $ext);
# Start init hook
$ext->_on_init($self);
if ((my $n_ns = $ext->_namespace) &&
(my $n_pref = $ext->_prefix)) {
$root->[2]->{"xmlns:$n_pref"} = $n_ns;
};
};
# Save extension list as attribute
$root->[2]->{'loy:ext'} = join('; ', @ext);
return $self;
};
# Get or add namespace to root
sub namespace {
my $self = shift;
# Get namespace
unless ($_[0]) {
return $self->SUPER::namespace || undef;
};
my $ns = pop;
my $prefix = shift;
# Get root element
my $root = $self->_root_element;
# No warning, but not able to set
return unless $root;
# Save namespace as attribute
$root->[2]->{'xmlns' . ($prefix ? ":$prefix" : '')} = $ns;
return $prefix;
};
# As another object
sub as {
my $self = shift;
# Base object
my $base = shift;
# New Loader
# my $loader = Mojo::Loader->new;
# Default 'XML::Loy::' prefix
if (index($base, '-') == 0) {
for ($base) {
# Was Loy prefix
s/^-Loy$/XML::Loy/;
s/^-/XML::Loy::/;
};
};
# Unable to load extension
if (my $e = load_class $base) {
carp "Exception: $e" if ref $e;
carp qq{Unable to load base class "$e"};
return;
};
# Create new base document
my $xml = $base->new( $self->to_string );
# Start init hook
$xml->_on_init;
# Set base namespace
if ($base->_namespace) {
$xml->namespace( $base->_namespace );
};
# Delete extension information
$xml->find('*[loy\:ext]')->each(
sub {
delete $_->{attrs}->{'loy:ext'}
}
);
# Add extensions
$xml->extension( @_ );
# Return XML document
return $xml;
};
# Render as pretty xml
sub to_pretty_xml {
my $self = shift;
return _render_pretty( shift // 0, $self->tree);
};
# Render subtrees with pretty printing
sub _render_pretty {
my $i = shift; # Indentation
my $tree = shift;
my $e = $tree->[0];
# No element
croak('No element') and return unless $e;
# Element is tag
if ($e eq 'tag') {
my $subtree =
[
@{ $tree }[ 0 .. 2 ],
[
@{ $tree }[ 4 .. $#$tree ]
]
];
return _element($i, $subtree);
}
# Element is text
elsif ($e eq 'text') {
my $escaped = $tree->[1];
for ($escaped) {
next unless $_;
# Escape and trim whitespaces from both ends
$_ = b($_)->xml_escape->trim;
};
return $escaped;
}
# Element is comment
elsif ($e eq 'comment') {
# Padding for every line
my $p = ' ' x $i;
my $comment = join "\n$p ", split(/;\s+/, $tree->[1]);
return "\n" . (' ' x $i) . "<!-- $comment -->\n";
}
# Element is processing instruction
elsif ($e eq 'pi') {
return (' ' x $i) . '<?' . $tree->[1] . "?>\n";
}
# Element is root
elsif ($e eq 'root') {
my $content;
# Pretty print the content
$content .= _render_pretty( $i, $tree->[ $_ ] ) for 1 .. $#$tree;
return $content;
};
};
# Render element with pretty printing
sub _element {
my $i = shift;
my ($type, $qname, $attr, $child) = @{ shift() };
# Is the qname valid?
croak "$qname is no valid QName"
unless $qname =~ /^(?:[a-zA-Z_]+:)?[^\s]+$/;
# Start start tag
my $content = (' ' x $i) . "<$qname";
# Add attributes
$content .= _attr((' ' x $i). (' ' x ( length($qname) + 2)), $attr);
# Has the element a child?
if ($child->[0]) {
# Close start tag
$content .= '>';
# There is only a textual child - no indentation
if (!$child->[1] && ($child->[0] && $child->[0]->[0] eq 'text')) {
# Special content treatment
if (exists $attr->{'loy:type'}) {
# With base64 indentation
if ($attr->{'loy:type'} =~ /^armour(?::(\d+))?$/i) {
my $n = $1 || 60;
my $string = $child->[0]->[1];
# Delete whitespace
$string =~ tr{\t-\x0d }{}d;
# Introduce newlines after n characters
$content .= "\n" . (' ' x ($i + 1));
$content .= join "\n" . ( ' ' x ($i + 1) ), (unpack "(A$n)*", $string );
$content .= "\n" . (' ' x $i);
}
# No special treatment
else {
# Escape
$content .= b($child->[0]->[1])->trim->xml_escape;
};
}
# No special content treatment indentation
else {
# Escape
$content .= b($child->[0]->[1])->trim->xml_escape;
};
}
# Treat children special
elsif (exists $attr->{'loy:type'}) {
# Raw
if ($attr->{'loy:type'} eq 'raw') {
foreach (@$child) {
# Create new dom object
my $dom = __PACKAGE__->new;
$dom->xml(1);
# Print without prettifying
$content .= $dom->tree($_)->to_string;
};
}
# Todo:
elsif ($attr->{'loy:type'} eq 'escape') {
$content .= "\n";
foreach (@$child) {
# Create new dom object
my $dom = __PACKAGE__->new;
$dom->xml(1);
# Pretty print
my $string = $dom->tree($_)->to_pretty_xml($i + 1);
# Encode
$content .= b($string)->xml_escape;
};
# Correct Indent
$content .= ' ' x $i;
};
}
# There are a couple of children
else {
my $offset = 0;
# First element is unformatted textual
if (!exists $attr->{'loy:type'} &&
$child->[0] &&
$child->[0]->[0] eq 'text') {
# Append directly to the last tag
$content .= b($child->[0]->[1])->trim->xml_escape;
$offset = 1;
};
# Start on a new line
$content .= "\n";
# Loop through all child elements
foreach (@{$child}[ $offset .. $#$child ]) {
# Render next element
$content .= _render_pretty( $i + 1, $_ );
};
# Correct Indent
$content .= (' ' x $i);
};
# End Tag
$content .= "</$qname>\n";
}
# No child - close start element as empty tag
else {
$content .= " />\n";
};
# Return content
return $content;
};
# Render attributes with pretty printing
sub _attr {
my $indent_space = shift;
my %attr = %{$_[0]};
# Delete special and namespace attributes
my @special = grep {
$_ eq 'xmlns:loy' || index($_, 'loy:') == 0
} keys %attr;
# Delete special attributes
delete $attr{$_} foreach @special;
# Prepare attribute values
$_ = b($_)->xml_escape->quote foreach values %attr;
# Return indented attribute string
if (keys %attr) {
return ' ' .
join "\n$indent_space", map { "$_=" . $attr{$_} } sort keys %attr;
};
# Return nothing
return '';
};
# Get root element (not as an object)
sub _root_element {
my $self = shift;
# Todo: Optimize! Often called!
# Find root (Based on Mojo::DOM::root)
my $root = $self->tree or return;
my $tag;
# Root is root node
if ($root->[0] eq 'root') {
my $i = 1;
# Search for the first tag
$i++ while $root->[$i] && $root->[$i]->[0] ne 'tag';
# Tag found
$tag = $root->[$i];
}
# Root is a tag
else {
# Tag found
while ($root->[0] eq 'tag') {
$tag = $root;
last unless my $parent = $root->[3];
$root = $parent;
};
};
# Return root element
return $tag;
};
# Autoload for extensions
sub AUTOLOAD {
my $self = shift;
my @param = @_;
# Split parameter
my ($package, $method) = our $AUTOLOAD =~ /^([\w\:]+)\:\:(\w+)$/;
# Choose root element
my $root = $self->_root_element;
# Get extension array
my @ext = $self->extension;
{
no strict 'refs';
foreach (@ext) {
# Method does not exist in extension
next unless $_->can($method);
# Release method
return *{ "${_}::$method" }->($self, @param);
};
};
my $errstr = qq{Can't locate "${method}" in "$package"};
if (@ext) {
$errstr .= ' with extension' . (@ext > 1 ? 's' : '');
$errstr .= ' "' . join('", "', @ext) . '"';
};
carp $errstr and return;
};
1;
__END__
=pod
=encoding utf8
=head1 NAME
XML::Loy - Extensible XML Reader and Writer
=head1 SYNOPSIS
use XML::Loy;
# Create new document with root node
my $xml = XML::Loy->new('env');
# Add elements to the document
my $header = $xml->add('header');
# Nest elements
$header->add('greetings')->add(title => 'Hello!');
# Append elements with attributes and textual data
$xml->add(body => { date => 'today' })->add(p => "That's all!");
# Use CSS3 selectors for element traversal
$xml->at('title')->attr(style => 'color: red');
# Attach comments
$xml->at('greetings')->comment('My Greeting');
# Print with pretty indentation
print $xml->to_pretty_xml;
# <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
# <env>
# <header>
#
# <!-- My Greeting -->
# <greetings>
# <title style="color: red">Hello!</title>
# </greetings>
# </header>
# <body date="today">
# <p>That's all!</p>
# </body>
# </env>
=head1 DESCRIPTION
L<XML::Loy> allows for the simple creation
of small serialized XML documents with
various namespaces.
It focuses on simplicity and extensibility,
while giving you the full power of L<Mojo::DOM>.
=head1 METHODS
L<XML::Loy> inherits all explicit methods from
L<Mojo::DOM> and implements the following new ones.
=head2 new
my $xml = XML::Loy->new(<<'EOF');
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<entry>
<fun>Yeah!</fun>
<entry>
EOF
$xml = XML::Loy->new('Document');
$xml = XML::Loy->new(Document => { foo => 'bar' });
my $xml_new = $xml->new(Document => {id => 'new'} => 'My Content');
Constructs a new L<XML::Loy> document.
Accepts either all parameters supported by L<Mojo::DOM> or
all parameters supported by L<add|/add>.
=head2 add
my $xml = XML::Loy->new('Document');
# Add an empty element
$xml->add('Element');
# Add elements with attributes
my $elem = $xml->add(Element => { type => 'text/plain' });
# Add nested elements with textual content
$elem->add(Child => "I'm a child element");
# Add elements with attributes, textual content, and a comment
$xml->add(p => { id => 'id_4' }, 'Hello!', 'My Comment!');
# Add elements with rules for pretty printing
$xml->add(Data => { -type => 'armour' }, 'PdGzjvj..');
# Add XML::Loy objects
$elem = $xml->new(Element => 'Hello World!');
$xml->add($elem);
Adds a new element to a L<XML::Loy> document, either
as another L<XML::Loy> object or newly defined.
Returns the root node of the added L<XML::Loy>
document.
Parameters to define elements are a tag name,
followed by an optional hash reference
including all attributes of the XML element,
an optional textual content,
and an optional comment on the element
(if the comment should be introduced to an empty element,
text content has to be C<undef>).
For giving directives for rendering element content
with L<pretty printing|/to_pretty_xml>,
a special C<-type> attribute can be defined:
=over 2
=item
C<escape>
XML escape the content of the node.
my $xml = XML::Loy->new('feed');
my $html = $xml->add(html => { -type => 'escape' });
$html->add(h1 => { style => 'color: red' } => 'I start blogging!');
$html->add(p => 'What a great idea!')->comment('First post');
print $xml->to_pretty_xml;
# <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
# <feed>
# <html>
# <h1 style="color: red">I start blogging!</h1>
#
# <!-- First post -->
# <p>What a great idea!</p>
# </html>
# </feed>
=item
C<raw>
Treat children as raw data (no pretty printing).
my $plain = XML::Loy->new(<<'PLAIN');
<entry>There is <b>no</b> pretty printing</entry>
PLAIN
my $xml = XML::Loy->new('entry');
my $text = $xml->add(text => { -type => 'raw' });
$text->add($plain);
print $xml->to_pretty_xml;
# <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
# <entry>
# <text><entry>There is <b>no</b> pretty printing</entry>
# </text>
# </entry>
=item
C<armour:n>
Indent the content and automatically
introduce linebreaks after every
C<n>th character.
Intended for base64 encoded data.
Defaults to 60 characters line-width after indentation.
my $xml = XML::Loy->new('entry');
my $b64_data = <<'B64';
VGhpcyBpcyBqdXN0IGEgdGVzdCBzdHJpbmcgZm
9yIHRoZSBhcm1vdXIgdHlwZS4gSXQncyBwcmV0
dHkgbG9uZyBmb3IgZXhhbXBsZSBpc3N1ZXMu
B64
my $data = $xml->add(
data => { -type => 'armour:30' } => $b64_data
);
$data->comment('This is base64 data!');
print $xml->to_pretty_xml;
# <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
# <entry>
#
# <!-- This is base64 data! -->
# <data>
# VGhpcyBpcyBqdXN0IGEgdGVzdCBzdH
# JpbmcgZm9yIHRoZSBhcm1vdXIgdHlw
# ZS4gSXQncyBwcmV0dHkgbG9uZyBmb3
# IgZXhhbXBsZSBpc3N1ZXMu
# </data>
# </entry>
=back
=head2 set
my $xml = XML::Loy->new('Document');
$xml->set(Element => { id => 5 });
# Overwrite
$xml->set(Element => { id => 6 });
Adds a new element as a child to the node only once.
Accepts all parameters as defined in L<add|/add>.
If one or more elements with the same tag name are
already children of the requesting node,
the old elements will be deleted and
comments will be merged if possible.
=head2 comment
$node = $node->comment('Resource Descriptor');
Prepends a comment to the current node.
If a node already has a comment, comments will be merged.
=head2 extension
# Add extensions
my $xml = $xml->extension('Fun', 'XML::Loy::Atom', -HostMeta);
# Further additions
$xml->extension(-Atom::Threading);
my @extensions = $xml->extension;
Adds or returns an array of extensions.
When adding, returns the document.
When getting, returns the array of associated extensions.
The extensions are associated to the document, they are not associated
to the object. That means, you can't add extensions to documents
without a root node.
With this package the following extensions are bundled:
L<Atom|XML::Loy::Atom>,
L<Atom-Threading|XML::Loy::Atom::Threading>,
L<ActivityStreams|XML::Loy::ActivityStreams>,
L<GeoRSS|XML::Loy::GeoRSS>,
L<OStatus|XML::Loy::OStatus>,
L<XRD|XML::Loy::XRD>,
and L<HostMeta|XML::Loy::HostMeta>.
If an extension has a leading minus symbol, it is assumed
to be located in the C<XML::Loy> namespace, making C<XML::Loy::Atom>
and C<-Atom> equivalent.
See L<Extensions|/EXTENSIONS> for further information.
B<Note:> The return value of the extension method is experimental
and may change without warnings.
=head2 as
my $xml = XML::Loy->new('<XRD><Subject>akron</Subject></XRD>');
my $xrd = $xml->as(-XRD, -HostMeta);
$xrd->alias('acct:akron@sojolicio.us');
print $xrd->to_pretty_xml;
# <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0"
# xmlns:hm="http://host-meta.net/xrd/1.0"
# xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
# <Subject>akron</Subject>
# <Alias>acct:akron@sojolicio.us</Alias>
# </XRD>
Convert an L<XML::Loy> based object to another object.
Accepts the base class and optionally a list of extensions.
This only changes the namespace of the base class - extensions
will stay intact.
See L<Extensions|/EXTENSIONS> for further information.
B<Note:> This method is experimental and may change without warnings!
=head2 mime
print $xml->mime;
The mime type associated with the object class.
See L<Extensions|/EXTENSIONS> for further information.
=head2 namespace
my $xml = XML::Loy->new('doc');
$xml->namespace('http://sojolicio.us/ns/global');
$xml->namespace(fun => 'http://sojolicio.us/ns/fun');
$xml->add('fun:test' => { foo => 'bar' }, 'Works!');
print $xml->namespace;
print $xml->to_pretty_xml;
# <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
# <doc xmlns="http://sojolicio.us/global"
# xmlns:fun="http://sojolicio.us/fun">
# <fun:test foo="bar">Works!</fun:test>
# </doc>
Returns the namespace of the node or
adds namespace information to the node's root.
When adding, the first parameter gives the prefix, the second one
the namespace. The prefix parameter is optional.
Namespaces are always added to the document's root,
that means,
they have to be unique in the scope of the whole document.
=head2 to_pretty_xml
print $xml->to_pretty_xml;
print $xml->to_pretty_xml(2);
Returns a stringified, pretty printed XML document.
Optionally accepts a numerical parameter,
defining the start of indentation (defaults to C<0>).
=head1 EXTENSIONS
package Fun;
use XML::Loy with => (
prefix => 'fun',
namespace => 'http://sojolicio.us/ns/fun',
mime => 'application/fun+xml'
);
# Add new methods to the object
sub add_happy {
my $self = shift;
my $word = shift;
my $cool = $self->add('-Cool');
my $cry = uc($word) . '!!! \o/ ';
$cool->add(Happy => {foo => 'bar'}, $cry);
};
L<XML::Loy> allows for inheritance
and thus provides two ways of extending the functionality:
By using a derived class as a base class or by extending a
base class with the L<extension|extension> method.
With this package the following extensions are bundled:
L<Atom|XML::Loy::Atom>,
L<Atom-Threading|XML::Loy::Atom::Threading>,
L<ActivityStreams|XML::Loy::ActivityStreams>,
L<GeoRSS|XML::Loy::GeoRSS>,
L<OStatus|XML::Loy::OStatus>,
L<XRD|XML::Loy::XRD>,
and L<HostMeta|XML::Loy::HostMeta>.
For the purpose of extension, three attributes can be set when
L<XML::Loy> is used (introduced with the keyword C<with>).
=over 2
=item
C<namespace> - Namespace of the extension.
=item
C<prefix> - Preferred prefix to associate with the namespace.
=item
C<mime> - Mime type of the base document.
=back
You can use derived objects in your application as you
would do with any other object class.
package main;
use Fun;
my $obj = Fun->new('Fun');
$obj->add_happy('Yeah!');
print $obj->to_pretty_xml;
# <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
# <Fun xmlns="http://sojolicio.us/ns/fun">
# <Cool>
# <Happy foo="bar">YEAH!!!! \o/ </Happy>
# </Cool>
# </Fun>
The defined namespace is introduced as the document's
namespace. The prefix is not in use for derived classes.
Without any changes to the class, you can use this module as an
extension to another L<XML::Loy> based document as well.
use XML::Loy;
my $obj = XML::Loy->new('object');
# Use XML::Loy based class 'Fun'
$obj->extension('Fun');
# Use methods provided by the base class or any extension
$obj->add_happy('Yeah!');
# Print with pretty indentation
print $obj->to_pretty_xml;
# <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
# <object xmlns:fun="http://sojolicio.us/ns/fun">
# <Cool>
# <fun:Happy foo="bar">YEAH!!!! \o/ </fun:Happy>
# </Cool>
# </object>
The defined namespace of C<Fun> is introduced with the
prefix C<fun>. The prefix is prepended to all elements
added by the L<add|/add> and L<set|/set> methods in the extension class.
To prevent this prefixing, prepend the element name with
a C<-> (like with C<E<lt>-Cool /E<gt>> in the example
above).
Derived classes are always C<strict> and C<utf8>, use C<warnings>
and import all C<features> of Perl 5.10.
=head1 DEPENDENCIES
L<Mojolicious>, L<Test::Warn> (for testing).
=head1 CAVEATS
L<XML::Loy> focuses on the comfortable handling of small documents of
serialized data and the ease of extensibility.
It is - as well as the underlying parser - written in pure perl and
not intended to be the fastest thing out there
(although I believe there's plenty of space for optimization).
That said - it may not suit all your needs, but there are loads of excellent
XML libraries out there, you can give a try then.
Just to name a few:
For fast parsing of huge documents, try L<XML::Twig>.
For validation and the availability of lots of tools from the XML world,
try L<XML::LibXML>.
For simple deserialization,
try L<XML::Bare> and L<XML::Fast>.
For similar scope, but without dependencies aside the core,
try L<XML::MyXML>.
=head1 CONTRIBUTORS
L<Renée Bäcker|https://github.com/reneeb>
=head1 AVAILABILITY
https://github.com/Akron/XML-Loy
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2011-2016, L<Nils Diewald|http://nils-diewald.de/>.
This program is free software, you can redistribute it
and/or modify it under the same terms as Perl.
=cut