Filtering XML file by ID - php

Question

Hello I have a problem when I am trying to parse an XML file
I am trying to display only one song content using id for example
mysongs.php?id=0
It's supposed to show "I left my heart on Europa" song
and if mysongs.php?id=1
It's supposed to show "Oh Ganymede" song
I want use ID instead of the songs numbers
My problem is when I am using [$id] instead of the number [0] didn't work
echo $mysongs->song[$id]->title;
Please how can I fix my problem
This is my XML file content songs.xml
<album>
<song dateplayed="2011-07-24 19:40:26">
<title>I left my heart on Europa</title>
<artist>Ship of Nomads</artist>
</song>
<song dateplayed="2011-07-24 19:27:42">
<title>Oh Ganymede</title>
<artist>Beefachanga</artist>
</song>
</album>
My PHP Code below
<?php
$id = $_GET['id'];
$mysongs = simplexml_load_file('songs.xml');
echo $mysongs->song[0]->title;
?>

Answer 1

It's probably a type issue.
Try to echo the type of your id, unless you parse it somewhere it will be a string:
<?php
$id = $_GET['id'];
echo gettype($id);
Then, when you do $mysongs->song[$id], it's not an equivalent of $mysongs->song[0] but of $mysongs->song['0'] which is not the same index.
So, to have the expected output, you should cast it to int before using it as an index. For that, you can use either a cast ($id = (int) $_GET['id'];) or if it is not available in your PHP version intval ($id = intval($_GET['id']);
Then the final result would look like to...
<?php
$id = (int) $_GET['id'];
$mysongs = simplexml_load_file('songs.xml');
echo $mysongs->song[$id]->title;

Answer 2

You will need to set id as part of the column parameter within the xml files
Try code below
<album>
<song dateplayed="2011-07-24 19:40:26">
<id>1</id>
<title>I left my heart on Europa</title>
<artist>Ship of Nomads</artist>
</song>
<song dateplayed="2011-07-24 19:27:42">
<id>2</id>
<title>Oh Ganymede</title>
<artist>Beefachanga</artist>
</song>
</album>
You can obtain the result using two method below
1.) Using Direct Elements Method
The following example gets the node value of the and element in the first and second elements in the ".xml" file:
<?php
$id = $_GET['id'];
$mysongs = simplexml_load_file('songs.xml')or die("Error: Cannot create object");
//get the first record
echo $mysongs->song[0]->id;
echo $mysongs->song[0]->title;
//get the second record
echo $mysongs->song[1]->id;
echo $mysongs->song[1]->title;
?>
2.) using Element looping method
<?php
$mysongs=simplexml_load_file("songs.xml") or die("Error: Cannot create object");
foreach($mysongs->children() as $song_album) {
echo $song_album->id . ", ";
echo $song_album->title . ", ";
echo $song_album->artist . "<br>";
}
?>