使用PHP從XML中具有相同父級的另一個子級的值中獲取子級的值

Question

我有以下XML文檔：

<response>
    <message>
        <badgeid>13</badgeid>
        <level>4672</level>
        <completion_time>1518626787</completion_time>
        <xp>4922</xp>
        <scarcity>9717</scarcity>
    </message>
    <message>
        <badgeid>25</badgeid>
        <level>1</level>
        <completion_time>1480166791</completion_time>
        <xp>25</xp>
        <scarcity>3761041</scarcity>
    </message>
    <message>
        <badgeid>21</badgeid>
        <level>1</level>
        <completion_time>1467581153</completion_time>
        <xp>100</xp>
        <scarcity>16650345</scarcity>
    </message>
</response>

我正在嘗試使用PHP創建一個程序，該程序返回某個“徽章”（總是唯一的）的“稀缺性”。

所以我的問題是：當我從用戶收到的唯一輸入是唯一的badgeid時，如何獲得<scarcity></scarcity>的值？ 概括地說：如何從同一個父母的另一個孩子的價值中獲得一個孩子的價值？

Answer 1

您還可以使用xpath表達式並將$badgeid用作參數：

$expression = "/response/message[./badgeid='$badgeid']";

然后，您可以使用SimpleXMLElement或DOMDocument 。

$data = <<<DATA
<response>
    <message>
        <badgeid>13</badgeid>
        <level>4672</level>
        <completion_time>1518626787</completion_time>
        <xp>4922</xp>
        <scarcity>9717</scarcity>
    </message>
    <message>
        <badgeid>25</badgeid>
        <level>1</level>
        <completion_time>1480166791</completion_time>
        <xp>25</xp>
        <scarcity>3761041</scarcity>
    </message>
    <message>
        <badgeid>21</badgeid>
        <level>1</level>
        <completion_time>1467581153</completion_time>
        <xp>100</xp>
        <scarcity>16650345</scarcity>
    </message>
</response>
DATA;

$badgeid = 25;
$xml = simplexml_load_string($data);
$expression = "/response/message[./badgeid='$badgeid']";
$items = $xml->xpath($expression);

if (count($items) === 1) {
    echo $items[0]->scarcity;
}

$doc = new DOMDocument();
$doc->loadXML($data);
$xpath = new DOMXpath($doc);
$res = $xpath->query($expression);

if ($res->length === 1) {
    echo $res->item(0)->getElementsByTagName("scarcity")->item(0)->nodeValue;
}

演示

Answer 2

你可以使用simplexml_load_string()為一個XML字符串，或simplexml_load_file()如果它是一個XML文件。 然后，您可以遍歷$xml->message並檢查$message->badgeid是否是您想要的項目：

$xmlstr = '<response>
    <message>
        <badgeid>13</badgeid>
        <level>4672</level>
        <completion_time>1518626787</completion_time>
        <xp>4922</xp>
        <scarcity>9717</scarcity>
    </message>
    <message>
        <badgeid>25</badgeid>
        <level>1</level>
        <completion_time>1480166791</completion_time>
        <xp>25</xp>
        <scarcity>3761041</scarcity>
    </message>
    <message>
        <badgeid>21</badgeid>
        <level>1</level>
        <completion_time>1467581153</completion_time>
        <xp>100</xp>
        <scarcity>16650345</scarcity>
    </message>
</response>';

$badgeid = 21 ; // The value you want to search
$xml = simplexml_load_string($xmlstr);
$scarcity = null ;
foreach ($xml->message as $message) {
    if ((string)$message->badgeid == $badgeid) {
        $scarcity = (string)$message->scarcity ;
        break ;
    }
}

// use $scarcity if set.
if (isset($scarcity)) {
    // do stuff
    echo $scarcity ; // 16650345
}