有两天我收到了使用DOM文件而不是正则表达式的建议
我仍然不知道如何正确使用查询
在下面的链接是会议“TERRITÓRIOEAMBIENTE”,我想获得下面4行的内容
https://cidades.ibge.gov.br/brasil/sp/sao-paulo/panorama
$html = file_get_contents( 'https://cidades.ibge.gov.br/brasil/sp/sao-paulo/panorama' );
$document = new DOMDocument();
$document->loadHTML(mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'));
$domxpath = new DOMXPath($document);
$paragraphs = $domxpath->query('
//th[*[
contains(text(), "TERRITÓRIO E AMBIENTE")
]
]
/following-sibling::tr[
position() = 12
]'
);
我把12个<tr>
的数量,因为这是源代码中出现的,但我不知道我是否正确地执行此查询,这对我来说是出现这些错误
Warning: DOMDocument::loadHTML(): Tag app invalid in Entity, line: 25
Warning: DOMDocument::loadHTML(): Misplaced DOCTYPE declaration in Entity, line: 25
Warning: DOMDocument::loadHTML(): htmlParseStartTag: misplaced <html> tag in Entity, line: 25
谢谢
您的代码中存在几个问题。
@$document->loadHTML($html);
//th[contains(text(), "Território e Ambiente")]/parent::tr/following-sibling::tr[1]/td[3]
得到一个包含文本th
的Território e Ambiente
元素,然后获取父tr
标签,然后转到下一个tr
兄弟,最后得到第三个td
元素(其中值为)。仍然非常脆弱,但要密切注意网站的变化,它不太可能改变。
所以现在你需要重复那个XPath查询3次,更改第n个tr
兄弟(添加两个,因为每个中间都有一个空元素)。它最终看起来像这样:
$document = new DOMDocument();
@$document->loadHTML($html);
$domxpath = new DOMXPath($document);
$paragraphs = $domxpath->query('//th[contains(text(), "Território e Ambiente")]/parent::tr/following-sibling::tr[1]/td[3]');
echo "First: ".preg_replace('/\s+/', ' ', $paragraphs[0]->nodeValue);
echo "<br>";
$paragraphs = $domxpath->query('//th[contains(text(), "Território e Ambiente")]/parent::tr/following-sibling::tr[3]/td[3]');
echo "Second: ".preg_replace('/\s+/', ' ', $paragraphs[0]->nodeValue);
echo "<br>";
$paragraphs = $domxpath->query('//th[contains(text(), "Território e Ambiente")]/parent::tr/following-sibling::tr[5]/td[3]');
echo "Third: ".preg_replace('/\s+/', ' ', $paragraphs[0]->nodeValue);
echo "<br>";
$paragraphs = $domxpath->query('//th[contains(text(), "Território e Ambiente")]/parent::tr/following-sibling::tr[7]/td[3]');
echo "Fourth: ".preg_replace('/\s+/', ' ', $paragraphs[0]->nodeValue);
第一:1.521,110平方公里 第二名:92.6% 第三名:74,8% 第四名:50,3%
注意使用preg_replace()
来摆脱丰富的空白。
使用更多的XPath魔法我们可以让它只使用一个查询:
//th[contains(text(), "Território e Ambiente")]/parent::tr/following-sibling::tr[position() mod 2 = 1]/td[3]
与其他人一样工作,但不是获得特定的tr
兄弟元素,而是获得其他所有元素。
$paragraphs = $domxpath->query('//th[contains(text(), "Território e Ambiente")]/parent::tr/following-sibling::tr[position() mod 2 = 1]/td[3]');
foreach ($paragraphs as $i => $p) {
echo ($i + 1)." value: ".preg_replace('/\s+/', ' ', $p->nodeValue);
echo "<br>";
}