PHP XPath 查询 XML？答案

【问题标题】：PHP XPath Query XML?PHP XPath 查询 XML？
【发布时间】：2015-04-05 21:46:42
【问题描述】：

我尝试制作一个可以在 XML 文档中搜索特定鱼的 PHP 文件。这是我写的：

$FISH_NAME = $_POST["fish_name"];
$LOCATION = $_POST["location"];
$STATUS = $_POST["status"];
$EDIBLE = $_POST["edible"];
$SCS_NAME = $_POST["scs_name"];
$COLOR = $_POST["color"];
$FEATURE = $_POST["feature"];


$varsPassed = array(
    $FISH_NAME => "NAME", 
    $LOCATION => "@LOCATION", 
    $STATUS => "STATUS", 
    $EDIBLE => "EDIBLE", 
    $SCS_NAME => "SCS-NAME", 
    $COLOR => "COLORS/COLOR", 
    $FEATURE => "FEATURES/FEATURE"
);

$conditional = "";

function addToCond($varPassed, $tagName) {
    if (!empty($varPassed)) {
        if(!empty($conditional)) {
            $conditional .= " and {$tagName} = '{$varPassed}'";
        }
        else {
            $conditional = "{$tagName} = '{$varPassed}'";
        }
    }
}

foreach($varsPassed as $current_feature => $current_tag_name) {
    addToCond($current_feature, $current_tag_Name);
    echo "{$current_feature}: {$current_tag_name}\n";
}

$query = "/FISHDICT/FISH[@LOCATION = 'REEF']";
echo $query;

$dom = new DOMDocument();
$dom->load('server/fish.xml');
$xpath = new DOMXpath($dom);
$value = $xpath->evaluate($query);
foreach($value as $item) {
    echo "found:  {$item->nodeValue}\n\n";
}

但它不起作用。我在网页上得到了回应：

神仙鱼：名称：特征/特征 /FISHDICT/FISH[@LOCATION = 'REEF']

有人知道为什么它不循环遍历每个 post 变量吗？

XML：

    <FISH location="REEF">
    <NAME>Angelfish</NAME>
    <COLORS>
        <COLOR> Blue </COLOR>
        <COLOR> Green </COLOR>
    </COLORS>
    <FEATURES> 
        <FEATURE> Round head </FEATURE>
        <FEATURE> Crown on head </FEATURE>
        <FEATURE> Tall tail fin </FEATURE>
    </FEATURES>
    <TAGS> 
        <TAG> REEF-FISH </TAG>
        <TAG> MULTICOLORED </TAG>
    </TAGS>
    <STATUS> ENDANGERED </STATUS>
    <DESCRIPTION> This fish is found in reefs and is common throughout Bermuda...</DESCRIPTION>
    <FISHINGLEGAL> FALSE </FISHINGLEGAL> 
    <DIET> 
        <DIETITEM> Algae </DIETITEM>
        <DIETITEM> Sea Plants </DIETITEM>
    </DIET>
    <EDIBLE> FALSE </EDIBLE> 
    <SCS-NAME> Holacanthus ciliaris </SCS-NAME>
</FISH>

【问题讨论】：

当我输入静态值时，您的脚本适用于我。您确定您的 POST 名称正确吗？也不确定您是否希望将来使用$conditional，但当前代码中不会有任何内容。

标签： php xml xpath

【解决方案1】：

从您的输出中，$varsPassed 数组显然不包含您所期望的。要调试，我会在文件顶部执行 print_r($_POST); 以查看帖子值是否符合您的预期。然后可能是 print_r($varsPassed); 在您创建该数组以确保它按预期填充之后。

顺便说一句，您的函数addToCond() 正在尝试将值附加到不在函数范围内的变量$conditional。您应该将函数更改为在调用代码中返回一个附加到 $conditional 的值，或者通过引用 $conditional 将其传递给函数。

【讨论】：