PHP: Read and extract data from an XML file

PHP File Handling: Exercise-16 with Solution

Write a PHP program that reads an XML file and extracts specific data from it.

books.xml

<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications 
      with XML.</description>
   </book>
   <book id="bk102">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies, 
      an evil sorceress, and her own childhood to become queen 
      of the world.</description>
   </book>
   <book id="bk103">
      <author>Corets, Eva</author>
      <title>Maeve Ascendant</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-11-17</publish_date>
      <description>After the collapse of a nanotechnology 
      society in England, the young survivors lay the 
      foundation for a new society.</description>
   </book>
   <book id="bk104">
      <author>Corets, Eva</author>
      <title>Oberon's Legacy</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2001-03-10</publish_date>
      <description>In post-apocalypse England, the mysterious 
      agent known only as Oberon helps to create a new life 
      for the inhabitants of London. Sequel to Maeve 
      Ascendant.</description>
   </book>
   <book id="bk105">
      <author>Corets, Eva</author>
      <title>The Sundered Grail</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2001-09-10</publish_date>
      <description>The two daughters of Maeve, half-sisters, 
      battle one another for control of England. Sequel to 
      Oberon's Legacy.</description>
   </book>
</catalog>

Sample Solution:

PHP Code :

<?php
$filename = "i:/books.xml";
$desiredAuthor = "Ralls, Kim";
echo "Search for the author: " . $desiredAuthor;
try {
    $xml = simplexml_load_file($filename);

    // Iterate over book elements and extract specific data based on condition
    foreach ($xml->book as $book) {
        $author = $book->author;

        if ($author == $desiredAuthor) {
            $title = $book->title;
            $price = $book->price;
            $genre = $book->genre;

            // Display the extracted data
            echo "</br>Title: " . $title . "\n";
            echo "</br>Genre: " . $genre . "\n";
            echo "</br>Price: " . $price . "\n";
        }
    }
} catch (Exception $e) {
    echo "An error occurred: " . $e->getMessage();
}
?>

Sample Output:

Search for the author: Ralls, Kim
Title: Midnight Rain
Genre: Fantasy
Price: 5.95

Explanation:

In the above exercise -

• The $filename variable holds the name of the XML file we want to read and extract data from.
• Inside the try block, we use the simplexml_load_file() function to load the XML file and parse it into a SimpleXMLElement object.
• In the event that there is an error loading the file or parsing the XML, we throw an exception with the error message "An error occurred."
• We then extract specific data from the XML using object notation (->) and the XML element names.
• Finally, we display the extracted data using the echo statement.

Flowchart:

PHP Code Editor:

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