Question

i have an xml file which contains around 60 books which i need to put into ascending order from the borrowedcount using php so far my code shows all the books but will not sort? any help would be really appriecated

PHP

<?php


$xmlassignDoc = new DOMDocument();
$xmlassignDoc->load("books.xml");


$books = $xmlBookDoc->getElementsByTagName("item");

foreach($books as $list)
{
    $course = $list->getElementsByTagName("course");
    $course = $course->item(0)->nodeValue;


//HERE is where the GET function will be
    if ($course == "CC150")
    {

    print_r($array);
        $id = $list->getAttribute("id");
        echo "<b>Book ID: </b> $id <br>";

         $title = $list->getElementsByTagName("title");
         $title = $title->item(0)->nodeValue;
         echo "<b>Title: </b> $title <br>";

         $isbn = $list->getElementsByTagName("isbn");
         $isbn = $isbn->item(0)->nodeValue;
         echo "<b>ISBN: </b> $isbn <br>";

         $borrowed = $list->getElementsByTagName("borrowedcount");
         $borrowed = $borrowed->item(0)->nodeValue;
         echo "<b>Borrowed Count: </b> $borrowed <br>";
         echo "<br>";
    } 
}
//print $xmlBookDoc->saveXML();
?>

xml file

<?xml version="1.0" encoding="utf-8"?>
<bookcollection>
<items>
  <item id="51390">
     <title>Management of systems development /</title>
     <isbn>0091653215</isbn>
     <url>http://library.hud.ac.uk/catlink/bib/51390</url>
     <borrowedcount>45</borrowedcount>
     <courses>
        <course>CC140</course>
        <course>CC210</course>
     </courses>
  </item>
  <item id="483">
     <title>Database systems management and design /</title>
     <isbn>0877091153</isbn>
     <url>http://library.hud.ac.uk/catlink/bib/483</url>
     <borrowedcount>28</borrowedcount>
     <courses>
        <course>CC140</course>
     </courses>
  </item>
  <item id="585842">
     <title>E-learning skills /</title>
     <isbn>0230573126</isbn>
     <url>http://library.hud.ac.uk/catlink/bib/585842</url>
     <borrowedcount>5</borrowedcount>
     <courses>
        <course>CC157</course>
     </courses>
  </item>

Answer 1

My solution:

$books = array();

$xml = simplexml_load_file('books.xml'); 

foreach($xml->items->item as $item) {
    $books[] = array(
                     'id'             => (string)$item->attributes()->id,
                     'title'          => (string)$item->title,
                     'isbn'           => (string)$item->isbn,
                     'course'         => (string)$item->courses->course[0],
                     'borrowed_count' => intval($item->borrowedcount)
                    );
}


array_sort_by_column($books, 'borrowed_count');

var_dump($books);

And the sorting function:

function array_sort_by_column(&$array, $column, $direction = SORT_ASC) {
    $reference_array = array();

    foreach($array as $key => $row) {
        $reference_array[$key] = $row[$column];
    }

    array_multisort($reference_array, $direction, $array);
}