使用XPath将无序列表HTML标记转换为多维数组

霞舞

发布时间：2025-08-12 18:08:01

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来源于php中文网

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使用xpath将无序列表html标记转换为多维数组

本文介绍了如何使用PHP的DOMDocument和DOMXPath类，结合XPath表达式，将包含状态信息的HTML无序列表转换为结构化的多维数组，并最终输出为JSON格式。重点在于使用XPath准确提取所需数据，并处理HTML中的空白字符，确保数据的准确性和可读性。

使用XPath解析HTML无序列表并转换为多维数组

在Web开发中，经常需要从HTML文档中提取数据。当数据以特定结构（例如无序列表）呈现时，使用XPath可以方便地定位和提取所需的信息。本教程将演示如何使用PHP的DOMDocument和DOMXPath类，将HTML无序列表转换为多维数组，并最终输出为JSON格式。

1. 加载HTML并创建DOMXPath对象

首先，需要将HTML字符串加载到DOMDocument对象中，并创建一个DOMXPath对象，以便使用XPath表达式查询DOM树。为了去除HTML中可能存在的空白字符，提高数据提取的准确性，可以使用自定义的loadHTML_noemptywhitespace函数。

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function loadHTML_noemptywhitespace(string $html, int $extra_flags = 0, int $exclude_flags = 0): \DOMDocument
{
    $flags = LIBXML_HTML_NODEFDTD | LIBXML_NOBLANKS | LIBXML_NONET;
    $flags = ($flags & ~ $exclude_flags) | $extra_flags;

    $domd = new \DOMDocument();
    $domd->preserveWhiteSpace = false;
    @$domd->loadHTML('' . $html, $flags);
    $removeAnnoyingWhitespaceTextNodes = function (\DOMNode $node) use (&$removeAnnoyingWhitespaceTextNodes): void {
        if ($node->hasChildNodes()) {
            // 递归处理子节点
            for ($i = $node->childNodes->length - 1; $i >= 0; --$i) {
                $removeAnnoyingWhitespaceTextNodes($node->childNodes->item($i));
            }
        }
        if ($node->nodeType === XML_TEXT_NODE && !$node->hasChildNodes() && !$node->hasAttributes() && ! strlen(trim($node->textContent))) {
            // 移除空白文本节点
            $node->parentNode->removeChild($node);
        }
    };
    $removeAnnoyingWhitespaceTextNodes($domd);
    return $domd;
}

$html = '


Status: Objeto em trânsito - por favor aguarde
Data  : 24/10/2021 | Hora: 12:04           
Origem: Unidade de Tratamento - Jaboatao Dos Guararapes / PE
Destino: Agência dos Correios - Cuitegi / PB



Status: Objeto em trânsito - por favor aguarde
Data  : 19/10/2021 | Hora: 00:03           
Origem: Unidade de Logística Integrada - Curitiba / PR
Destino: Unidade de Tratamento - Recife / PE



Status: Fiscalização aduaneira finalizada
Data  : 18/10/2021 | Hora: 23:35
Local: Unidade Operacional - Curitiba / PR



Status: Objeto recebido pelos Correios do Brasil
Data  : 16/10/2021 | Hora: 11:45
Local: Unidade de Logística Integrada - Curitiba / PR



Status: Objeto postado
Data  : 14/10/2021 | Hora: 20:30
Local: País -  / 


';

$domd=loadHTML_noemptywhitespace($html);
$xp=new DOMXPath($domd);

2. 使用XPath查询UL元素

使用XPath表达式//div[contains(@class,'singlepost')]/ul选择所有包含singlepost类的div元素下的ul元素。

$extracted=[];
foreach($xp->query("//div[contains(@class,'singlepost')]/ul") as $ul){
    $ulData=[];
    // ...
}

3. 提取LI元素中的数据

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在每个ul元素中，使用XPath表达式./li选择所有的li元素。然后，使用explode函数将每个li元素的文本内容按冒号分隔，提取键值对，并将其存储到$ulData数组中。

foreach($xp->query("./li", $ul) as $li){
    $data = explode(":",$li->nodeValue, 2);
    $uldata[trim($data[0])] = trim($data[1]);
}
$extracted[]=$uldata;

4. 将结果转换为JSON格式

最后，使用json_encode_pretty函数将提取的数据转换为JSON格式，并输出。json_encode_pretty函数可以格式化JSON输出，使其更易于阅读。

function json_encode_pretty($data, int $extra_flags = 0, int $exclude_flags = 0): string
{
    // prettiest flags for: 7.3.9
    $flags = JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | (defined("JSON_UNESCAPED_LINE_TERMINATORS") ? JSON_UNESCAPED_LINE_TERMINATORS : 0) | JSON_PRESERVE_ZERO_FRACTION | (defined("JSON_THROW_ON_ERROR") ? JSON_THROW_ON_ERROR : 0);
    $flags = ($flags | $extra_flags) & ~ $exclude_flags;
    return (json_encode($data, $flags));
}

echo json_encode_pretty($extracted);

完整代码示例

preserveWhiteSpace = false;
    @$domd->loadHTML('' . $html, $flags);
    $removeAnnoyingWhitespaceTextNodes = function (\DOMNode $node) use (&$removeAnnoyingWhitespaceTextNodes): void {
        if ($node->hasChildNodes()) {
            // Warning: it's important to do it backwards; if you do it forwards, the index for DOMNodeList might become invalidated;
            // that's why i don't use foreach() - don't change it (unless you know what you're doing, ofc)
            for ($i = $node->childNodes->length - 1; $i >= 0; --$i) {
                $removeAnnoyingWhitespaceTextNodes($node->childNodes->item($i));
            }
        }
        if ($node->nodeType === XML_TEXT_NODE && !$node->hasChildNodes() && !$node->hasAttributes() && ! strlen(trim($node->textContent))) {
            //echo "Removing annoying POS";
            // var_dump($node);
            $node->parentNode->removeChild($node);
        } //elseif ($node instanceof DOMText) { echo "not removed"; var_dump($node, $node->hasChildNodes(), $node->hasAttributes(), trim($node->textContent)); }
    };
    $removeAnnoyingWhitespaceTextNodes($domd);
    return $domd;
}

$html = '


Status: Objeto em trânsito - por favor aguarde
Data  : 24/10/2021 | Hora: 12:04           
Origem: Unidade de Tratamento - Jaboatao Dos Guararapes / PE
Destino: Agência dos Correios - Cuitegi / PB



Status: Objeto em trânsito - por favor aguarde
Data  : 19/10/2021 | Hora: 00:03           
Origem: Unidade de Logística Integrada - Curitiba / PR
Destino: Unidade de Tratamento - Recife / PE



Status: Fiscalização aduaneira finalizada
Data  : 18/10/2021 | Hora: 23:35
Local: Unidade Operacional - Curitiba / PR



Status: Objeto recebido pelos Correios do Brasil
Data  : 16/10/2021 | Hora: 11:45
Local: Unidade de Logística Integrada - Curitiba / PR



Status: Objeto postado
Data  : 14/10/2021 | Hora: 20:30
Local: País -  / 


';

$domd=loadHTML_noemptywhitespace($html);
$xp=new DOMXPath($domd);
$extracted=[];
foreach($xp->query("//div[contains(@class,'singlepost')]/ul") as $ul){
    $ulData=[];
    foreach($xp->query("./li", $ul) as $li){
        $data = explode(":",$li->nodeValue, 2);
        $uldata[trim($data[0])] = trim($data[1]);
    }
    $extracted[]=$uldata;
}
echo json_encode_pretty($extracted);

?>