use v6;

class XML::Writer {

    method serialize($tree?, *%named) {
        my $t;
        my $err = "Please pass exactly one argument to XML::Writer.serialize";
        if defined($tree) {
            die $err unless +%named == 0;
            $t = $tree;
        } else {
            die $err unless +%named == 1;
            $t = %named.pairs.[0];
        }
        die 'The XML tree must have a single root node'
            unless 1 == $t.elems && $.is_element($t);
        $.visit($t.list);
    }

    method is_attribute($x) { $x ~~ Pair && $x.value !~~ Positional };
    method is_element($x)   { $x ~~ Pair && $x.value ~~ Positional };
    method is_text_node($x) { ($x ~~ Str) || ($x ~~ Numeric) };
    method is_node($x)      { $.is_element($x) || $.is_text_node($x) };

    method element($name, @attrs, @children) {
        @children
          ??  $.element_open($name, @attrs)
              ~ $.visit(@children)
              ~ $.element_close($name)
          !!  $.element_empty($name, @attrs);
    }

    method element_open($name, @attrs) {
        sprintf '<%s%s>', $name, $.element_attrs(@attrs);
    }

    method element_close($name) {
        "</$name>";
    }

    method element_empty($name, @attrs) {
        sprintf '<%s%s />', $name, $.element_attrs(@attrs);
    }

    method element_attrs(@attrs) {
        [~] @attrs.flatmap({ sprintf ' %s="%s"', .key, $.escape(.value) });
    }

    method escape($str) {
        my %charmap =
            '>' => '&gt;',
            '<' => '&lt;',
            '"' => '&quot;',
            '&' => '&amp;',
            ;
        $str.subst( rx/ <[<>&"]> /, -> $x { %charmap{~$x} }, :g);
    }

    method visit(@list) {
        my $result = '';
        my $last-newline-since = 0;
        for @list -> $node {
            if $.is_text_node($node) {
                $result ~= $.escape($node);
            }
            else {
                my ($name, $subtree) = $node.kv;
                my @attrs    = grep {$.is_attribute($_) }, $subtree.list;
                my @children = grep {$.is_node($_) },      $subtree.list;
                $result ~= $.element($name, @attrs, @children);
                if $result.chars - $last-newline-since > 70 {
                    $result ~= "\n";
                    $last-newline-since = $result.chars;
                }
            }
        }
        $result;
    }
}



NAME
XML::Writer - XML generation and handling


head

code

=begin code
use v6;
use XML::Writer;

my $svg = :svg[
    :width(200), :height(200),
    circle => [
        :cx(100), :cy(100), :r(50)
    ],
    text => [
        :x(10), :y(20), "hello"
    ]
];

say XML::Writer.serialize($svg);
=end code


XML::Writer is a Perl 6 class which outputs XML from a nested data structure
describing the DOM representation of an XML file.


TESTING
The testing plan of SVG::Tiny seems alluring. Haven't looked closer at it,
though.


BUGS
Likely several. If any of them bites you, please get in touch and we'll see
what we can do.


AUTHORS
Carl Mäsak (masak on CPAN githubperl6, cmasak on gmail.com)
significant contributions made by Daniel Schröer and Moritz Lenz.


root

README

React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>

=item1 B<Resources>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>

=end nested
=begin nested :!nested

=item1 B<Resoures>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>
    =item2 L<empty|#>

=end nested
=end React


=begin React :component<CookieConsent> :id<CookieConsent> :buttonCaption("Got it!")
=para
This website uses cookies for analytics.
=end React


Writer

NAME XML::Writer - XML generation and handling

SYNOPSIS

DESCRIPTION

METHODS

serialize($hierarchy)

TESTING The testing plan of SVG::Tiny seems alluring. Haven't looked closer at it, though.

BUGS Likely several. If any of them bites you, please get in touch and we'll see what we can do.

AUTHORS Carl Mäsak (masak on CPAN github #perl6, cmasak on gmail.com) significant contributions made by Daniel Schröer and Moritz Lenz.