perl xml::sax 解析

Question

您好，我有一个 xml 如下:

<employees>
    <employee>
        <firstname>John</firstname>
        <lastname>Doe</lastname>
                  <age>gg</age>
        <department>Operations</department>
        <amount Ccy="EUR">100</amount>
        <joinDate> 12/12/2011 </joinDate>    
    </employee>
     <employee>
        <firstname>John1111</firstname>
        <lastname>Doe1111</lastname>
               <age>gg</age>
        <department>Operations</department>
        <amount Ccy="EUR">200</amount>
        <joinDate> 12/13/2011 </joinDate>    
    </employee>
</employees>

我想使用 xml::sax 解析它。所以我覆盖了 start_element 和 end_element 以及字符方法。我必须处理两种我不确定如何处理的情况。 1) 如果 joinDate 为 null，则将 joinDate 作为 sysdate。 2) 将金额相加并得到一个值作为 totalAmount。如何在 perl 中使用 XML::SAX 模块来做到这一点。

请告诉我我需要覆盖哪个方法才能执行此操作，一小段代码会有所帮助。

谢谢，斯里坎特

Answer 1

这很简单:

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
use XML::SAX::ParserFactory;
use XML::SAX::PurePerl;
use Date::Calc 'Today';

my $today = sprintf("%02d/%02d/%4d", (Today())[1,2,0]);

# Alternatively if you can't use Date::Calc:
# my @localtime = localtime;
# my $today = sprintf("%02d/%02d/%4d", $localtime[4]+1, $localtime[2], $localtime[5]+1900);

my (@joindates, $total_amount, $buffer);

my $factory = new XML::SAX::ParserFactory;
my $handler = new XML::SAX::PurePerl;
my $parser = $factory->parser(
                  Handler => $handler,
                  Methods => {
                      characters => sub {
                          $buffer = shift->{Data};
                          $buffer =~ s/^\s+|\s+$//g;
                      },
                      end_element => sub {
                          return unless shift->{LocalName} =~ /^(amount|joinDate)$/;
                          push @joindates, $buffer || $today if $1 eq 'joinDate';
                          $total_amount += $buffer if $1 eq 'amount';
                      }
                  }
                  );
$parser->parse_uri("sample.xml");

print "Total amount: $total_amount\n";
printf("Join dates:\n%s\n", join("\n", @joindates));

输出:

Total amount: 300
Join dates:
12/12/2011
12/13/2012