如何使用Perl的XML :: Twig向子元素添加属性? [英] How can I add an attribute to a child element using Perl's XML::Twig?

问题描述

我有一个像这样的XML字符串:

I have an XML string like this:

<DATA>
   <CHILD_DATA ATVAL="value1"/>
   <CHILD_DATA />
</DATA>

我想要的最终输出是:

<DATA>
   <CHILD_DATA ATVAL="value1"/>
   <CHILD_DATA ATVAL="value2"/>
</DATA>

我的树枝$t在<DATA>.现在，我想向第二个<CHILD_DATA />添加一个属性.该属性为ATVAL="value2".我尝试了以下方法:

My twig $t is at <DATA>. Now I want to add an attribute to the second <CHILD_DATA />. The attribute is ATVAL="value2". I tried the following:

$t->last_child('CHILD_DATA')->set_att{"ATVAL","value2"};

这不起作用.此代码有什么问题?还有另一种方法吗?

This didn't work. What's wrong with this code? Is there another way to do this?

推荐答案

正如乔恩向您暗示的那样，您在发布的代码中存在语法错误.您应该已经看到编译错误，例如:

As Jon hinted to you, you have a syntax error in the code you posted. You should have seen a compile error like:

测试行18-> set_att {"附近的

语法错误 由于编译错误，program.pl的执行中止了.

syntax error at test line 18, near "->set_att{" Execution of program.pl aborted due to compilation errors.

但是，您可能已在答案中输入了代码，以使代码与您的实际操作不符.始终将实际代码放入您的问题中，而不是重新键入它，并始终在可能的情况下发布完整的程序.当您发布程序时，我不必从头开始调试我认为您可能正在做的事情. :)

However, you might have typed the code into your answer so that code doesn't match what you are actually doing. Always put the actual code into your question rather than re-typing it, and always post a full program when you can. When you post your program, I don't have to start from scratch to debug what I think you might be doing. :)

这是一个满足您需求的程序:

Here's a program that does what you want:

#!/usr/bin/perl

use XML::Twig;

my $xml = <<'XML';
<DATA>
   <CHILD_DATA ATVAL="value1"/>
   <CHILD_DATA />
</DATA>
XML

my $twig= XML::Twig->new( keep_spaces => 1 );

    $twig->parse( $xml );

    $t = $twig->root;

    $t->last_child('CHILD_DATA')->set_att("ATVAL" => "value2");

$twig->flush;

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