如何在PHP中解析XML并提取posList值到数组？

我对XML并不熟悉，一直尝试将XML文件中的数据解析到PHP数组中，但进展不大。目前已实现提取predefinedLocationReference的id和名称，但缺少提取posList值并添加到数组的方法。

XML内容 #

<ns2:messageContainer xmlns="datex2.eu/schema/3/common" xmlns:ns2="datex2.eu/schema/3/messageContainer" xmlns:ns3="datex2.eu/schema/3/exchangeInformation" xmlns:ns4="datex2.eu/schema/3/informationManagement" xmlns:ns5="datex2.eu/schema/3/dataDictionaryExtension" xmlns:ns6="datex2.eu/schema/3/cctvExtension" xmlns:ns7="datex2.eu/schema/3/locationReferencing" xmlns:ns8="datex2.eu/schema/3/alertCLocationCodeTableExtension" xmlns:ns9="datex2.eu/schema/3/extension" xmlns:ns10="datex2.eu/schema/3/roadTrafficData" xmlns:ns11="datex2.eu/schema/3/vms" xmlns:ns12="datex2.eu/schema/3/situation" modelBaseVersion="3">
    <ns2:payload xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="ns7:PredefinedLocationsPublication" lang="no" modelBaseVersion="3">
        <publicationTime>2023-01-25T13:56:15.615+01:00</publicationTime>
        <publicationCreator>
            <country>no</country>
            <nationalIdentifier>NPRA</nationalIdentifier>
        </publicationCreator>
        <ns7:headerInformation>
            <confidentiality>noRestriction</confidentiality>
            <informationStatus>real</informationStatus>
        </ns7:headerInformation>

        <ns7:predefinedLocationReference xsi:type="ns7:PredefinedLocation" id="100356" version="1">
            <ns7:predefinedLocationName>
                <values>
                    <value lang="no">Eikås - Åsanevegen</value>
                </values>
            </ns7:predefinedLocationName>
            <ns7:location xsi:type="ns7:LinearLocation">
                <ns7:gmlLineString srsName="http://www.opengis.net/gml/srs/epsg.xml#32633">
                    <ns7:posList>-27946 6743813</ns7:posList>
                </ns7:gmlLineString>
            </ns7:location>
        </ns7:predefinedLocationReference>
        <ns7:predefinedLocationReference xsi:type="ns7:PredefinedLocation" id="100361" version="1">
            <ns7:predefinedLocationName>
                <values>
                    <value lang="no">Ammerud - Bjerke</value>
                </values>
            </ns7:predefinedLocationName>
            <ns7:location xsi:type="ns7:LinearLocation">
                <ns7:gmlLineString srsName="http://www.opengis.net/gml/srs/epsg.xml#32633">
                    <ns7:posList>269553 6653843</ns7:posList>
                </ns7:gmlLineString>
            </ns7:location>
        </ns7:predefinedLocationReference>
    </ns2:payload>
    <ns2:exchangeInformation modelBaseVersion="3">
        <ns3:exchangeContext>
            <ns3:codedExchangeProtocol>snapshotPull</ns3:codedExchangeProtocol>
            <ns3:exchangeSpecificationVersion>3</ns3:exchangeSpecificationVersion>
            <ns3:supplierOrCisRequester>
                <ns3:internationalIdentifier>
                    <country>no</country>
                    <nationalIdentifier>NPRA</nationalIdentifier>
                </ns3:internationalIdentifier>
            </ns3:supplierOrCisRequester>
        </ns3:exchangeContext>
        <ns3:dynamicInformation>
            <ns3:exchangeStatus>undefined</ns3:exchangeStatus>
            <ns3:messageGenerationTimestamp>2023-01-25T13:56:15.615+01:00</ns3:messageGenerationTimestamp>
        </ns3:dynamicInformation>
    </ns2:exchangeInformation>
</ns2:messageContainer>

现有PHP代码 #

$xml = simplexml_load_string($response->raw_body, "SimpleXMLElement", LIBXML_NOCDATA, 'ns2', true);

$xml->registerXPathNamespace('ns7','http://datex2.eu/schema/3/locationReferencing');

$count = 0;
foreach($xml->xpath('//ns7:predefinedLocationReference') as $event) {

    $return[$count]['id'] = intval($event->attributes()->id);
    $predefinedLocationName = $event->xpath('ns7:predefinedLocationName');
    foreach ($predefinedLocationName[0]->values as $locVal) {
        $return[$count]['name'] = strval($locVal->value);
    }

    $count++;
}

当前输出结果 #

[
    {
        "id": 100356,
        "name": "Eikås - Åsanevegen"
    },
    {
        "id": 100361,
        "name": "Ammerud - Bjerke"
    }
]

解决方案 #

在现有循环中添加提取posList的逻辑，利用已注册的命名空间通过XPath定位节点，提取文本值后可直接存入数组，或拆分坐标为子数组：

$xml = simplexml_load_string($response->raw_body, "SimpleXMLElement", LIBXML_NOCDATA, 'ns2', true);

$xml->registerXPathNamespace('ns7','http://datex2.eu/schema/3/locationReferencing');

$return = [];
foreach($xml->xpath('//ns7:predefinedLocationReference') as $event) {
    $item = [];
    // 提取ID
    $item['id'] = intval($event->attributes()->id);
    
    // 提取名称
    $predefinedLocationName = $event->xpath('ns7:predefinedLocationName');
    if (!empty($predefinedLocationName)) {
        $item['name'] = strval($predefinedLocationName[0]->values->value);
    }
    
    // 提取posList值
    $posListNodes = $event->xpath('ns7:location/ns7:gmlLineString/ns7:posList');
    if (!empty($posListNodes)) {
        $posValue = trim(strval($posListNodes[0]));
        // 可选1：直接存储字符串
        // $item['posList'] = $posValue;
        // 可选2：拆分为坐标数组
        $item['posList'] = explode(' ', $posValue);
    }
    
    $return[] = $item;
}

修改后输出结果 #

[
    {
        "id": 100356,
        "name": "Eikås - Åsanevegen",
        "posList": ["-27946", "6743813"]
    },
    {
        "id": 100361,
        "name": "Ammerud - Bjerke",
        "posList": ["269553", "6653843"]
    }
]

内容的提问来源于stack exchange，提问作者JIMJA