XML DOM & nested elements

[tgavin]

I'm trying to nest multiple elements in my XML output using the PHP5 DOM.

I want to get this, but can't get a nested element to work. Is what I'm trying to do illegal?

<items>
	<books>
		<writers>
			<author>
				<name></name>
				<title></title>
				<publisher></publisher>
			</author>
			<author>
				<name></name>
				<title></title>
				<publisher></publisher>
			</author>
		</writers>
	</books>
</items>

<?php
$books = array();
$books [] = array(
'title' => 'PHP Hacks',
'name' => 'Jack Herrington',
'publisher' => "O'Reilly"
);
$books [] = array(
'title' => 'Podcasting Hacks',
'name' => 'Jack Herrington',
'publisher' => "O'Reilly"
);

$doc = new DOMDocument();
$doc->formatOutput = true;

$r = $doc->createElement("items");
$doc->appendChild( $r );

foreach($books as $book) {
  $b = $doc->createElement( "books" );
  
  // nested element
    $b = $doc->createElement( "writers" );
    
    $b = $doc->createElement( "author" );
  
  $name = $doc->createElement( "name" );
  $name->appendChild($doc->createTextNode( $book['name'] ));
  $b->appendChild( $name );
  
  $title = $doc->createElement( "title" );
  $title->appendChild($doc->createTextNode( $book['title'] ));
  $b->appendChild( $title );
  
  $publisher = $doc->createElement( "publisher" );
  $publisher->appendChild($doc->createTextNode( $book['publisher'] ));
  $b->appendChild( $publisher );
  
  $r->appendChild( $b );
}

echo $doc->saveXML();
?>

[Mittineague]

I tried your code and get

<?xml version="1.0"?>
<items>
  <author>
    <name>Jack Herrington</name>
    <title>PHP Hacks</title>
    <publisher>O'Reilly</publisher>
  </author>
  <author>
    <name>Jack Herrington</name>
    <title>Podcasting Hacks</title>
    <publisher>O'Reilly</publisher>
  </author>
</items>

So "books" and "writers" are missing. Maybe they need to be appended?

[tgavin]

So "books" and "writers" are missing. Maybe they need to be appended?

That's the problem. How do I get those in there?

[bhanson]

Read your code like English, you have a grammatical error in your formatting.

Your foreach loop basically reads "foreach author", yet you're trying to include <writers> & <books> inside of it, but should instead encapsulate it.

You can append <books> to the end of <item>, and <writers> to the end of <books> and then run your loop to append <author> on the end of <writers>.

Here's your code, modified to show you what you're doing wrong:

<?php
$books = array();
$books [] = array(
'title' => 'PHP Hacks',
'name' => 'Jack Herrington',
'publisher' => "O'Reilly"
);
$books [] = array(
'title' => 'Podcasting Hacks',
'name' => 'Jack Herrington',
'publisher' => "O'Reilly"
);

$doc = new DOMDocument();
$doc->formatOutput = true;

$r = $doc->createElement("items");
$doc->appendChild( $r );


/** CHANGE */
$foo = $doc->createElement('foo');
$r->appendChild($foo);


foreach($books as $book) {
  // SNIP, this doesn't make sense, and you're overriding the variable anyway

  $b = $doc->createElement( "author" );
  
  $name = $doc->createElement( "name" );
  $name->appendChild($doc->createTextNode( $book['name'] ));
  $b->appendChild( $name );
  
  $title = $doc->createElement( "title" );
  $title->appendChild($doc->createTextNode( $book['title'] ));
  $b->appendChild( $title );
  
  $publisher = $doc->createElement( "publisher" );
  $publisher->appendChild($doc->createTextNode( $book['publisher'] ));
  $b->appendChild( $publisher );
  
  $foo->appendChild( $b ); // You were appending directly on the end of items...
}

echo $doc->saveXML();

[tgavin]

Thank you! That got me straightened out. It's confusing at first, but one you finally catch on it's pretty easy