Question

下面的程序给了我奇怪的输出，我无法解释：

use strict;
use warnings;
use XML::Twig;

my $xml = 
q{<block>
    <foo>bar baz</foo>
</block>};

my $twig = XML::Twig->new(
        TwigHandlers => {foo => \&foo, block => \&block},
    );

print "after parse: " . $twig->parse($xml)->sprint;


sub foo {
    my ( $twig, $foo ) = @_;

    my $text = $foo->sprint("don't print outside element");
    my $newSummary = XML::Twig::Elt->parse( '<p><i>' . $text . '</i></p>' );
    $newSummary->paste( 'before', $foo);
    my $parent = $foo->parent;
    # $foo->delete;
    print "foo: " . $parent->sprint . "\n\n";
}

sub block {
    my ($twig, $block) = @_;
    print "block: " . $block->sprint . "\n\n";
}

它打印以下内容：

foo: <block><p><i>bar baz</i></p><foo>bar baz</foo></block>

block: <block><p><i>bar baz</i></p><foo>bar baz</foo></block>

after parse: <block><foo>bar baz</foo></block>

所以我正在修改foo处理程序内部的树枝，更改是为了block处理程序来查看它，但是当处理完成后，更改就会消失。这里发生了什么？如何在枝条的整个生命周期内改变我的变化？

Answer 1

你没有归还任何东西。删除子例程中的print语句，您将获得以下输出：

after parse: <block><p><i>bar baz</i></p><foo>bar baz</foo></block>

XML :: Twig更改已删除

1 个答案: