Compare and filter two xml files in php

Question

I want to compare two xml files in PHP (actually filter one by the second), one xml file contains for example "interfaces" data another contains interfaces(rule.xml) but with less elements just what i want exactly, and want to get filtered data which is in both of xmls.

First xml:

`<?xml version="1.0" encoding="UTF-8"?>
<data>
  <interfaces>
    <interface>
        <name><!-- type: string --></name>
        <type><!-- type: string --></type>
        <mtu><!-- type: int32 --></mtu>
    <interface>
</interfaces>
</data>`

Second xml :

`<?xml version="1.0" encoding="UTF-8"?>
<data>
  <interfaces>
    <interface>
      <name>interfacename</name>
      <type>gigaeth</type>
      <mtu>1500</mtu>
      <counters>
        <inBytes>17800</inBytes>
        <inPackets>156000</inPackets>
        <inErrors>850</inErrors>
      </counters>
    </interface>
  </interfaces>
</data>`

So the result that i want is :

`<?xml version="1.0" encoding="UTF-8"?>
<data>
  <interfaces>
    <interface>
      <name>interfacename</name>
      <type>gigaeth</type>
      <mtu>1500</mtu>
   </interface>
  </interfaces>
</data>`

I really don't understand what you are trying to achieve here. You want the data from the second xml, but with less elements ? (skipping the `counters` tag?) Please elaborate if possible. — Niek van der Steen, May 29 '15 at 10:00
yes that what i want to filter the second one by the first xml and just keep similar tags. — Junior12, May 29 '15 at 10:07

splash58 · Accepted Answer · 2015-05-30T20:09:39.603

2

Using simplexml to recursively walk both xml trees synchronously. At leaf node of the first xml check that the same node presents in the second one and change the value

$xml1 = new SimpleXMLElement($str1);
$xml2 = new SimpleXMLElement($str2);

function set(&$xml, $xml2) {
    foreach($xml as $key => $xmlpos) {
        if (isset($xml2->$key))
          if($xmlpos->count()) set($xmlpos, $xml2->$key);
          else  $xml->$key =  $xml2->$key;
    }
}

set($xml1, $xml2);
echo $xml1->saveXML();

edited May 30 '15 at 20:09

answered May 29 '15 at 14:49

splash58

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just a question about how to get the function working with a pre-generated xml1 and xml2 ? in a other meaning, i already have the two xml files. how can i call them ? – Junior12 Jun 04 '15 at 09:59
does `set($xml1, $xml2);` is not what you ask? – splash58 Jun 04 '15 at 10:05
smthg like : set('../../file1.xml', '../../file2.xml') – Junior12 Jun 04 '15 at 11:42
no. try so `$xml1 = new SimpleXMLElement($url1,,true);` must work but i never used. – splash58 Jun 04 '15 at 12:22

Compare and filter two xml files in php

1 Answers1