Several ways to write and read XML in PHP

  • 2020-05-27 04:29:10
  • OfStack

1. Generate and read XML files using DOM
Example 1:
 
<?php 
//Creates XML string and XML document using the DOM 
$dom = new DomDocument('1.0'); 
//add root - <books> 
$books = $dom->appendChild($dom->createElement_x_x ('books')); 
//add <book> element to <books> 
$book = $books->appendChild($dom->createElement_x_x ('book')); 
//add <title> element to <book> 
$title = $book->appendChild($dom->createElement_x_x ('title')); 
//add <title> text node element to <title> 
$title->appendChild($dom->createTextNode('Great American Novel')); 
//generate xml 
$dom->formatOutput = true; // set the formatOutput attribute of domDocument to true 
//save XML as string or file 
$test1 = $dom->saveXML(); // put string in test1 
$dom -> save('test1.xml'); // save as file 
?> 

Example 2:
 
$aa = "111"; 
$xmlstr = <<<XML 
<?xml version='1.0'?> 
<document> 
<title>{$aa}</title> 
<from>Joe</from> 
<to>Jane</to> 
<body> 
I know that's the answer -- but what's the question? 
</body> 
</document> 
XML; 
$dom = new domDocument; 
$dom->loadXML($xmlstr); 
$test1 = $dom->saveXML(); 
$dom->save('test1.xml'); 


Example 3:
test1.xml:
 
<?xml version="1.0"?> 
<books> 
<book> 
<author>Jack Herrington</author> 
<title>PHP Hacks</title> 
<publisher>O'Reilly</publisher> 
</book> 
<book> 
<author>Jack Herrington</author> 
<title>Podcasting Hacks</title> 
<publisher>O'Reilly</publisher> 
</book> 
</books> 


example.php:
 
$doc = new DOMDocument(); 
$doc->load('test1.xml'); 
$books = $doc->getElementsByTagName("book"); 
foreach($books as $book){ 
$authors = $book->getElementsByTagName("author"); 
$author = $authors->item(0)->nodeValue; 
$publishers = $book->getElementsByTagName( "publisher" ); 
$publisher = $publishers->item(0)->nodeValue; 
$titles = $book->getElementsByTagName( "title" ); 
$title = $titles->item(0)->nodeValue; 
echo "$title - $author - $publisher\n"; 
} 


2. Generate and read xml files using simple
Example 1:
 
<? 
$xmlstr = <<<XML 
<?xml version='1.0' standalone='yes'?> 
<books> 
<book> 
<title>Great American Novel</title> 
<characters> 
<character> 
<name>Cliff</name> 
<desc>really great guy</desc> 
</character> 
<character> 
<name>Lovely Woman</name> 
<desc>matchless beauty</desc> 
</character> 
<character> 
<name>Loyal Dog</name> 
<desc>sleepy</desc> 
</character> 
</characters> 
<plot> 
Cliff meets Lovely Woman. Loyal Dog sleeps, but wakes up to bark 
at mailman. 
</plot> 
<success type='bestseller'>4</success> 
<success type='bookclubs'>9</success> 
</book> 
</books> 
XML; 

// Extract node content  
$xml = new SimpleXMLElement($xmlstr); 
foreach ($xml->book[0]->success as $success) { 
switch((string) $success['type']) { // Get attributes as element indices 
case 'bestseller': 
echo $success. ' months on bestseller list<br>'; 
break; 
case 'bookclubs': 
echo $success. ' bookclub listings'; 
break; 
} 
} 

// Modify the text node content  
$xml = new SimpleXMLElement($xmlstr); 
$xml->book[0]->characters->character[0]->name = 'Big Cliff'; 
echo $xml->asXML(); 

// Add a text node for the child element  
$xml = new SimpleXMLElement($xmlstr); 
$character = $xml->book[0]->characters->addChild('character'); 
$character->addChild('name', 'Yellow Cat'); 
$character->addChild('desc', 'aloof'); 
$success = $xml->book[0]->addChild('success', '2'); 
$success->addAttribute('type', 'reprints'); 
echo $xml->asXML(); 

?> 


Example 2:
 
if (file_exists('test1.xml')) { // read xml file  
$xml = simplexml_load_file('test1.xml'); 
var_dump(xml); 
} else { 
exit('Failed to open test1.xml.'); 
} 


3.DOM and simple interoperate
DOM imports simpleXML:
 
<?php 
$sxe = simplexml_load_string('<books><book><title>Great American 
Novel</title></book></books>'); 
if ($sxe === false) { 
echo 'Error while parsing the document'; 
exit; 
} 
$dom_sxe = dom_import_simplexml($sxe); 
if (!$dom_sxe) { 
echo 'Error while converting XML'; 
exit; 
} 
$dom = new DOMDocument('1.0'); 
$dom_sxe = $dom->importNode($dom_sxe, true); 
$dom_sxe = $dom->appendChild($dom_sxe); 
$test2 = $dom->saveXML(); // put string in test2 
$dom -> save('test2.xml'); // save as file 
?> 


simpleXML import DOM:
 
<?php 
$dom = new domDocument; 
$dom->loadXML('<books><book><title>Great American 
Novel</title></book></books>'); 
if (!$dom) { 
echo 'Error while parsing the document'; 
exit; 
} 
$s = simplexml_import_dom($dom); 
echo $s->book[0]->title; // Great American Novel 
?> 

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