属性为的XML更改值

Question

With PHP I want to change the value in the node where attribute is something I specify. The XML file:

<?xml version='1.0' standalone='yes'?>
<days>
<Maandag id="1">0</Maandag>
<Dinsdag     id="2">0</Dinsdag>
<Woensdag    id="3">0</Woensdag>
<Donderdag   id="4">0</Donderdag>
<Vrijdag     id="5">0</Vrijdag>
<Zaterdag    id="6">0</Zaterdag>
<Zonday  id="0">0</Zonday>  
</days>

For example: Today is Monday so jddayofweek(0) = 1 Then the value of the node with id=1 needs to change, so in the end we get:

<?xml version='1.0' standalone='yes'?>
<days>
<Maandag id="1">3</Maandag>
<Dinsdag     id="2">0</Dinsdag>
<Woensdag    id="3">0</Woensdag>
<Donderdag   id="4">0</Donderdag>
<Vrijdag     id="5">0</Vrijdag>
<Zaterdag    id="6">0</Zaterdag>
<Zonday  id="0">0</Zonday>  
</days>

How do I do this in PHP?

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Answer 1

I'd recommend simpleXML, because it is - well - simple:

$xml = simplexml_load_string($x); // assume XML in $x
$id = 1; 

$day = $xml->xpath("*[@id=`$id`]")[0];
$day[0] = 5;

see the result:

echo $xml->asXML();

Comments:

• the xpath-expression will select the day by $id and give back an array of SimpleXML-elements.
• select the 1st element (index [0]) and store it in $day (requires PHP >= 5.4)

see it working: https://eval.in/388827

Thinking further

If you make that XML, add clarity and flexibility by making it like this:

<days>
    <day name="Maandag" id="1">0</day>
    <day name="Dinsdag" id="2">0</day>
    <etc />
</days>