在节点值上运行PHP函数然后输出XML？

Question

I have an XML that im getting from file_get_contents. It contains a bunch of values including encrypted ones which are inside <strStringValue>. I have a function that will decrypt them, i tried to use this code but it just printed out the values inside strStringValue:

    <?php
if (!isset($HTTP_RAW_POST_DATA)) {
    $HTTP_RAW_POST_DATA = file_get_contents("php://input"); 
    $doc = new DOMDocument();
    $doc->loadXML($HTTP_RAW_POST_DATA);
    $stringvalue = $doc->getElementsByTagName('strStringValue');
    foreach ($stringvalue as $strstringvalue) {
             echo $strstringvalue->nodeValue, PHP_EOL;
    }

    include("Decrypt1.php");
    $in = "$strstringvalue";

    $HTTP_RAW_POST_DATA2=Decrypt1($in);
    echo("$HTTP_RAW_POST_DATA2");
    }
?>

Here is an example of what the XML looks like:

Encrypted

<string>
<Id>1</Id>
<strStringCaption>file-commision</strStringCaption>
<strStringValue enc="0">2734sad87asd78asdt8a7d6874slwe9832t</strStringValue>
</string>
<string>
<Id>2</Id>
<strStringCaption>file-shop</strStringCaption>
<strStringValue enc="0">78sd7asgd87adg87g873g78dad</strStringValue>
</string>

Decrypted

<string>
<Id>1</Id>
<strStringCaption>file-commision</strStringCaption>
<strStringValue enc="0">commisions.txt</strStringValue>
</string>
<string>
<Id>2</Id>
<strStringCaption>file-shop</strStringCaption>
<strStringValue enc="0">shoplist.xml</strStringValue>
</string>
<string>
<string>

Answer 1

You could do it via XSL(T) and XSLTProcessor::registerPHPFunctions

(sorry for the tons and tons of boilerplate code)

<?php
echo "
------- src -------
";
$xml = getDocData();
echo $xml;

echo "
------- process #1 (encrypt) -------
";
$xml = process($xml);
echo $xml;

echo "
------- process #2 (decrypt) -------
";
$xml = process($xml);
echo $xml;

function myEncrypt($plain) { 
    // just a demo, not even pretending to do proper encryption
    return 'sosecret:'.strrev($plain);
}

function myDecrypt($encrypted) {
    $prefix = 'sosecret:';
    $cbPrefix = strlen($prefix);
    if ( 0===strncmp($encrypted, $prefix, $cbPrefix) ) {
        return strrev(substr($encrypted, $cbPrefix));
    }
    return 'error';
}

function process($xml) {
    $processor = getXSLT(getStyleData());
    $doc = getDocument($xml);
    return $processor->transformToXML($doc);
}

function getXSLT($xml) {
    $doc = getDocument($xml);
    $proc = new XSLTProcessor();
    $proc->registerPHPFunctions( array('myEncrypt', 'myDecrypt'));
    $proc->importStyleSheet($doc);
    return $proc;
}

function getDocument($xml) {
    $doc = new DOMDocument;
    $doc->loadxml($xml);
    return $doc;
}


function getDocData() {
    return <<< EOX
<doc>   
    <string>
        <Id>1</Id>
        <strStringCaption>file-commision</strStringCaption>
        <strStringValue enc="0">commisions.txt</strStringValue>
    </string>
    <string>
        <Id>2</Id>
        <strStringCaption>file-shop</strStringCaption>
        <strStringValue enc="0">shoplist.xml</strStringValue>
    </string>
</doc>
EOX;
}

function getStyleData() {
    return <<< EOX
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:php="http://php.net/xsl">
<xsl:output method="xml"/>
    <xsl:template match="strStringValue[@enc='0']">
        <strStringValue enc="1">
            <xsl:value-of select="php:function('myEncrypt',string(.))"/>
        </strStringValue>
    </xsl:template>
    <xsl:template match="strStringValue[@enc='1']">
        <strStringValue enc="0">
            <xsl:value-of select="php:function('myDecrypt',string(.))"/>
        </strStringValue>
    </xsl:template>
    <xsl:template match="@*|node()">
      <xsl:copy>
        <xsl:apply-templates select="@*|node()"/>
      </xsl:copy>
    </xsl:template>
</xsl:stylesheet>
EOX;
}

prints

------- src -------
<doc>   
    <string>
        <Id>1</Id>
        <strStringCaption>file-commision</strStringCaption>
        <strStringValue enc="0">commisions.txt</strStringValue>
    </string>
    <string>
        <Id>2</Id>
        <strStringCaption>file-shop</strStringCaption>
        <strStringValue enc="0">shoplist.xml</strStringValue>
    </string>
</doc>
------- process #1 (encrypt) -------
<?xml version="1.0"?>
<doc>   
    <string>
        <Id>1</Id>
        <strStringCaption>file-commision</strStringCaption>
        <strStringValue xmlns:php="http://php.net/xsl" enc="1">sosecret:txt.snoisimmoc</strStringValue>
    </string>
    <string>
        <Id>2</Id>
        <strStringCaption>file-shop</strStringCaption>
        <strStringValue xmlns:php="http://php.net/xsl" enc="1">sosecret:lmx.tsilpohs</strStringValue>
    </string>
</doc>

------- process #2 (decrypt) -------
<?xml version="1.0"?>
<doc>   
    <string>
        <Id>1</Id>
        <strStringCaption>file-commision</strStringCaption>
        <strStringValue xmlns:php="http://php.net/xsl" enc="0">commisions.txt</strStringValue>
    </string>
    <string>
        <Id>2</Id>
        <strStringCaption>file-shop</strStringCaption>
        <strStringValue xmlns:php="http://php.net/xsl" enc="0">shoplist.xml</strStringValue>
    </string>
</doc>

but how to get rid of the @!#§! xmlns:php="http://php.net/xsl" attribute is beyond my capabilities right now.

<xsl:template match="@*|node()"> is a basic "copy-it-all template". It matches almost anything that has no "better" match and just copies the source node as-is to the target.

<xsl:template match="strStringValue[@enc='0']"> is the template that matches the strStringValue elements that are not encrypted and "replaces" it in the target with the encrypted version via myEncrypt($plain).

<xsl:template match="strStringValue[@enc='1']"> does the reverse thing via myDecrypt($encrypted).