Question

在一些讨厌的嵌套表上使用Web :: Scrape，没有CSS样式。必须学习XPATH，然后绊倒。

更新：修复了一些XPATH问题，现在只剩下一个关于属性的问题了

#!perl
use warnings;
use Web::Scraper;
use Data::Dumper;

my $html = do { local $/; <DATA> };
my $scraper = scraper {
    # Wrong! The 'tbody' element does not exist.
    # process ".//[@id='cfg-surface-detail']/center/table/tbody/tr/td[2]/select",
    # I used Chrome to get the XPath, and it inserts tbody elements when rendering bad HTML
    # also, I changed the start of the XPATH from './/' to '//*'
    # which I think means "relative to anywhere" or something.
    process "//*[@id='cfg-surface-detail']/center/table/tr/td[2]/select",
        'sensorType[]' => 'TEXT';
};

my $res = $scraper->scrape($html);
print Dumper($res);

__DATA__
<html><head><title>...</title></head>
<body>
    <form action="/foo" method=post id=cfg-surface-detail name=cfg-surface-detail>
        <center>
        <table bgcolor="#FFFFFF">
            <tr><td>Sensor Type</td><td>
            <select name="cfg-sensor-type"  >
                <option value="1 Fred's Sensor" selected>Fred's Sensor
                <option value="2 Other">Other Sensor
            </select>
            </td></tr>
        </table>
        </center>
    </form>
</body>
</html>

此现在输出：

$VAR1 = {
      'sensorType' => [
                        'Fred\'s Sensor Other Sensor '
                      ]
    };

所以我越来越近了。现在，我如何指定具有<option>属性的selected？

更新：已解决。 Xpath是//*[@id="cfg-surface-detail"]/center/table/tr/td[2]/select/option[@selected]

这有助于：http://www.w3schools.com/xpath/xpath_syntax.asp

Answer 1

#!perl
use warnings;
use Web::Scraper;
use Data::Dumper;

my $html = do { local $/; <DATA> };
my $scraper = scraper {
      process '#cfg-surface-detail//select',
        'sensorType[]' => 'TEXT';
};

my $res = $scraper->scrape($html);
print Dumper($res);

__DATA__
<html><head><title>...</title></head>
<body>
    <form action="/foo" method=post id=cfg-surface-detail name=cfg-surface-detail>
        <center>
        <table bgcolor="#FFFFFF">
            <tr><td>Sensor Type</td><td>
            <select name="cfg-sensor-type"  >
                <option value="1 Fred's Sensor" selected>Fred's Sensor
                <option value="2 Other">Other Sensor
            </select>
            </td></tr>
        </table>
        </center>
    </form>
</body>
</html>

Answer 2

如果是我，我会选择css。所选选项的Css解决方案是：

'select[name="cfg-sensor-type"] option[selected]'

Answer 3

答案有点来自之前的两个答案：

$scraper = scraper {
    process '//select[@name="cfg-sensor-type"]/option[@selected]', 'SensorType' => 'TEXT';
};

Web :: Scrape with Xpath返回太多行

3 个答案: