使用php中的simplexml，使用来自子元素的数据来选择其他元素中的数据 - using data from child element to select data in other element using simplexml in php

using data from child element to select data in other element using simplexml in php

因此，我在php中使用simplexml将xml文件中的元素显示到网页上。当在某个特定元素中选择一个完整列表的子元素时，这可以很好地工作。然而，问题是，我需要在一个元素中选择一些规则，并显示附加在另一个元素的这些特定规则上的数据。

为了澄清，这是我的xml文件的简化版本（它包含了我需要的一切）：

<report>
    <profile_info>  
    <rules>
        <rule id="RUL1">
            <display_name>
            XMP does not have CreateDate entry in the XMP Basic Schema
            </display_name>
            <display_comment>
            This entry of the predefined XMP Basic Schema defines the date and time when the document has been created. It is required by some PDF-based ISO standards.
            </display_comment>
        </rule>
        <rule id="RUL133">
            <display_name>
            XMP does not have a VersionID entry in the XMP Media Management Schema
            </display_name>
            <display_comment>
            The VersionID in the XMP Media Management Schema (xmpMM) is the version identifier for respective resource. This entry is required by some PDF-based ISO standards for file identification.
            </display_comment>
        </rule>
        <rule id="RUL169">
            <display_name>
            Page does not have TrimBox or ArtBox
            </display_name>
            <display_comment>
            Either ArtBox or TrimBox should be defined for pages in a PDF file that are used in prepress. PDF/X ISO standards require the presence of one of these boxes.
            </display_comment>
        </rule>
    </rules>
</profile_info>

<results>
    <hits rule_id="RUL169" severity="Error">
    </hits>
    <hits rule_id="RUL133" severity="Error">
    </hits>
</results>
</report>

到目前为止，我已经能够在php中使用simplexml用display_name和display_comment来回显整个规则列表。

然而，这不是我想要的。我希望能够只显示实际给出错误的规则的子元素，如根元素"results"中所示。

总结一下我的问题：取<results>中出现错误的规则的id，并使用它们来显示另一个根元素<rules>中显示的display_name和display_comment。

这是我迄今为止所拥有的php代码，列出了整个有效的规则列表，如果这有任何帮助的话。（这是有效的，但这不是我想要的btw）

<?php
    if(file_exists('../uploads/reports/report.xml')){
    $xml = simplexml_load_file('../uploads/reports/report.xml');
    } 
    else{
    exit('Could not load the file ...');
    }
foreach ($xml->profile_info as $profile_info){
    foreach ($profile_info->rules as $rules){
        foreach ($rules->rule as $rule){
                echo '<div id="name">'.$rule->display_name.'</div>'.'<div id="comment">'.$rule
                    ->display_comment.'</div>';
?>

提前感谢！

使用SimpleXMLElement::xpath和array_map函数的解决方案：

$xml = simplexml_load_file('../uploads/reports/report.xml');
...
$hits = $xml->xpath("results/hits/@rule_id");
$ruleIds = array_map(function($v){    // getting search path for each needed rule
    return "profile_info/rules/rule[@id='". (string)$v. "']"; 
}, $hits);
foreach ($xml->xpath(implode(" | ", $ruleIds)) as $rule) {
    echo '<div id="name">'. $rule->display_name .'</div>'.
         '<div id="comment">'. $rule->display_comment .'</div>';
}

"视图源"输出：

        <div id="name">
        XMP does not have a VersionID entry in the XMP Media Management Schema
        </div><div id="comment">
        The VersionID in the XMP Media Management Schema (xmpMM) is the version identifier for respective resource. This entry is required by some PDF-based ISO standards for file identification.
        </div><div id="name">
        Page does not have TrimBox or ArtBox
        </div><div id="comment">
        Either ArtBox or TrimBox should be defined for pages in a PDF file that are used in prepress. PDF/X ISO standards require the presence of one of these boxes.
        </div>