SimpleXML
- Введение
- Installing/Configuring
- Предопределенные константы
- Примеры
- SimpleXML Функции
- SimpleXMLElement->addAttribute() — Adds an attribute to the SimpleXML element
- SimpleXMLElement->addChild() — Adds a child element to the XML node
- SimpleXMLElement->asXML() — Return a well-formed XML string based on SimpleXML element
- SimpleXMLElement->attributes() — Identifies an element's attributes
- SimpleXMLElement->children() — Finds children of given node
- SimpleXMLElement->__construct() — Creates a new SimpleXMLElement object
- SimpleXMLElement->getDocNamespaces() — Returns namespaces declared in document
- SimpleXMLElement->getName() — Gets the name of the XML element
- SimpleXMLElement->getNamespaces() — Returns namespaces used in document
- SimpleXMLElement->registerXPathNamespace() — Creates a prefix/ns context for the next XPath query
- SimpleXMLElement->xpath() — Runs XPath query on XML data
- simplexml_import_dom — Get a SimpleXMLElement object from a DOM node.
- simplexml_load_file — Interprets an XML file into an object
- simplexml_load_string — Interprets a string of XML into an object
Коментарии
Here are two quick and dirty functions that use SimpleXML to detect if a feed xml is RSS or ATOM:
<?php
function is_rss($feedxml) {
@$feed = new SimpleXMLElement($feedxml);
if ($feed->channel->item) {
return true;
} else {
return false;
}
}
function is_atom($feedxml) {
@$feed = new SimpleXMLElement($feedxml);
if ($feed->entry) {
return true;
} else {
return false;
}
}
?>
The functions take in the full text feed (retrieved via cURL, for example) and return a true or a false based on the result.
Storing SimpleXMLElement values in $_SESSION does not work. Saving the results as an object or individual elements of the object will result in the dreaded "Warning: session_start() [function.session-start]: Node no longer exists" error.
For example, this does not work:
$xml = new SimpleXMLElement($page);
$country = $xml->Response->Placemark->AddressDetails->Country->CountryNameCode;
$_SESSION['country'] = $country;
This will work:
$_SESSION['country'] = (string) $country;
To add to what others have said, you can't directly put a $_GET or $_POST value into a variable then into an attribute using SimpleXML. You must first convert it to an integer.
This will NOT work
<?php
$page_id = $_GET['id'];
echo $xml->page[$page_id]
?>
You will get something like:
Notice: Trying to get property of non-object in /Applications/MAMP/htdocs/mysite/index.php on line 10
However, this WILL work and is much simpler then using (string) or other methods.
<?php
$page_id = intval($_GET['id']);
echo $xml->page[$page_id]
?>
I had a problem with simplexml reading nodes from an xml file. It always return an SimpleXML-Object but not the text inside the node.
Example:
<?xml version="1.0" encoding="UTF-8"?>
<Test>
<Id>123</Id>
</Test>
Reading this xml into a variable called $xml and then doing the following
<?php
$myId = $xml->Id;
?>
Did not return 123 in $myId, but instead I got a SimpleXMLElement Object.
The solution is simple, when you know it. Use explicit string conversion.
<?php
$myId = (string)$xml->Id;
?>
while using simple xml and get double or float int value from xml object for using math operations (+ * - / ) some errors happens on the operation, this is because of simple xml returns everythings to objects.
exmple;
<?php
$name = "somestring";
$size = 11.45;
$xml = '
<xml>
<name>somestring</name>
<size>11.45</size>
</xml>';
$xmlget = simplexml_load_string($xml)
echo $xml->size*2; // 20 its false
// ($xml->size is an object (int)11 and (45) )
// this is true
echo $size*2; // 22.90
echo (float)$size*2; // 22.90
?>
dynamic sql in php using xml:
test.xml:
<?xml version="1.0" encoding="UTF-8"?>
<sql>
<statement>
SELECT * FROM USERS
<call criteria="byId">WHERE id = %d</call>
<call criteria="byUsername">WHERE username = "%s"</call>;
</statement>
</sql>
index.php:
<?php
function callMe($param) {
$search = array('byUsername' => 'dynsql');
if (isset($search[$param[1]])) {
return sprintf($param[2], $search[$param[1]]);
}
return "";
}
$xml = simplexml_load_file("test.xml");
$string = $xml->statement->asXML();
$string = preg_replace_callback('/<call criteria="(\w+)">(.*?)<\/call>/', 'callMe', $string);
$node = simplexml_load_string($string);
echo $node;
?>
obviously, this example can be improved [in your own code.]
If you tried to load an XML file with this, but the CDATA parts were not loaded for some reason, is because you should do it this way:
$xml = simplexml_load_file($this->filename, 'SimpleXMLElement', LIBXML_NOCDATA);
This converts CDATA to String in the returning object.
Here's a quick way to dump the nodeValues from SimpleXML into an array using the path to each nodeValue as key. The paths are compatible with e.g. DOMXPath. I use this when I need to update values externally (i.e. in code that doesn't know about the underlying xml). Then I use DOMXPath to find the node containing the original value and update it.
<?php
function XMLToArrayFlat($xml, &$return, $path='', $root=false)
{
$children = array();
if ($xml instanceof SimpleXMLElement) {
$children = $xml->children();
if ($root){ // we're at root
$path .= '/'.$xml->getName();
}
}
if ( count($children) == 0 ){
$return[$path] = (string)$xml;
return;
}
$seen=array();
foreach ($children as $child => $value) {
$childname = ($child instanceof SimpleXMLElement)?$child->getName():$child;
if ( !isset($seen[$childname])){
$seen[$childname]=0;
}
$seen[$childname]++;
XMLToArrayFlat($value, $return, $path.'/'.$child.'['.$seen[$childname].']');
}
}
?>
Use like this:
<?php
$xml = simplexml_load_string(...some xml string...);
$xmlarray = array(); // this will hold the flattened data
XMLToArrayFlat($xml, $xmlarray, '', true);
?>
You can also pull multiple files in one array:
<?php
foreach($files as $file){
$xml = simplexml_load_file($file);
XMLToArrayFlat($xml, $xmlarray, $file.':', true);
}
?>
The respective filename/path is thus prefixed to each key.
Here's a function I came up with to convert an associative array to XML. Works for multidimensional arrays as well.
<?php
function assocArrayToXML($root_element_name,$ar)
{
$xml = new SimpleXMLElement("<?xml version=\"1.0\"?><{$root_element_name}></{$root_element_name}>");
$f = create_function('$f,$c,$a','
foreach($a as $k=>$v) {
if(is_array($v)) {
$ch=$c->addChild($k);
$f($f,$ch,$v);
} else {
$c->addChild($k,$v);
}
}');
$f($f,$xml,$ar);
return $xml->asXML();
}
?>
The BIGGEST differece between an XML and a PHP array is that in an XML file, the name of elements can be the same even if they are siblings, eg. "<pa><ch /><ch /><ch /></pa>", while in an PHP array, the key of which must be different.
I think the array structure developed by svdmeer can fit for XML, and fits well.
here is an example array converted from an xml file:
array(
"@tag"=>"name",
"@attr"=>array(
"id"=>"1","class"=>"2")
"@text"=>"some text",
)
or if it has childrens, that can be:
array(
"@tag"=>"name",
"@attr"=>array(
"id"=>"1","class"=>"2")
"@items"=>array(
0=>array(
"@tag"=>"name","@text"=>"some text"
)
)
Also, I wrote a function that can change that array back to XML.
<?php
function array2XML($arr,$root) {
$xml = new SimpleXMLElement("<?xml version=\"1.0\" encoding=\"utf-8\" ?><{$root}></{$root}>");
$f = create_function('$f,$c,$a','
foreach($a as $v) {
if(isset($v["@text"])) {
$ch = $c->addChild($v["@tag"],$v["@text"]);
} else {
$ch = $c->addChild($v["@tag"]);
if(isset($v["@items"])) {
$f($f,$ch,$v["@items"]);
}
}
if(isset($v["@attr"])) {
foreach($v["@attr"] as $attr => $val) {
$ch->addAttribute($attr,$val);
}
}
}');
$f($f,$xml,$arr);
return $xml->asXML();
}
?>
Three line xml2array:
<?php
$xml = simplexml_load_string($xmlstring);
$json = json_encode($xml);
$array = json_decode($json,TRUE);
?>
Ta da!
Here is a recursive function that will convert a given SimpleXMLElement object into an array, preserving namespaces and attributes.
<?php
function xmlObjToArr($obj) {
$namespace = $obj->getDocNamespaces(true);
$namespace[NULL] = NULL;
$children = array();
$attributes = array();
$name = strtolower((string)$obj->getName());
$text = trim((string)$obj);
if( strlen($text) <= 0 ) {
$text = NULL;
}
// get info for all namespaces
if(is_object($obj)) {
foreach( $namespace as $ns=>$nsUrl ) {
// atributes
$objAttributes = $obj->attributes($ns, true);
foreach( $objAttributes as $attributeName => $attributeValue ) {
$attribName = strtolower(trim((string)$attributeName));
$attribVal = trim((string)$attributeValue);
if (!empty($ns)) {
$attribName = $ns . ':' . $attribName;
}
$attributes[$attribName] = $attribVal;
}
// children
$objChildren = $obj->children($ns, true);
foreach( $objChildren as $childName=>$child ) {
$childName = strtolower((string)$childName);
if( !empty($ns) ) {
$childName = $ns.':'.$childName;
}
$children[$childName][] = xmlObjToArr($child);
}
}
}
return array(
'name'=>$name,
'text'=>$text,
'attributes'=>$attributes,
'children'=>$children
);
}
?>
Simple means simple. If you know the structure and just want the value of a tag:
<?php
$xml = simplexml_load_file($xmlfile);
print $xml->City->Street->Address->HouseColor;
?>
Warning, numbers can come out as strings, empty elements like <HouseColor></HouseColor> come out as array(0)
Wrapper XMLReader class, for simple SAX-reading huge xml:
https://github.com/dkrnl/SimpleXMLReader
Usage example: http://github.com/dkrnl/SimpleXMLReader/blob/master/examples/example1.php
<?php
/**
* Simple XML Reader
*
* @license Public Domain
* @author Dmitry Pyatkov(aka dkrnl) <dkrnl@yandex.ru>
* @url http://github.com/dkrnl/SimpleXMLReader
*/
class SimpleXMLReader extends XMLReader
{
/**
* Callbacks
*
* @var array
*/
protected $callback = array();
/**
* Add node callback
*
* @param string $name
* @param callback $callback
* @param integer $nodeType
* @return SimpleXMLReader
*/
public function registerCallback($name, $callback, $nodeType = XMLREADER::ELEMENT)
{
if (isset($this->callback[$nodeType][$name])) {
throw new Exception("Already exists callback $name($nodeType).");
}
if (!is_callable($callback)) {
throw new Exception("Already exists parser callback $name($nodeType).");
}
$this->callback[$nodeType][$name] = $callback;
return $this;
}
/**
* Remove node callback
*
* @param string $name
* @param integer $nodeType
* @return SimpleXMLReader
*/
public function unRegisterCallback($name, $nodeType = XMLREADER::ELEMENT)
{
if (!isset($this->callback[$nodeType][$name])) {
throw new Exception("Unknow parser callback $name($nodeType).");
}
unset($this->callback[$nodeType][$name]);
return $this;
}
/**
* Run parser
*
* @return void
*/
public function parse()
{
if (empty($this->callback)) {
throw new Exception("Empty parser callback.");
}
$continue = true;
while ($continue && $this->read()) {
if (isset($this->callback[$this->nodeType][$this->name])) {
$continue = call_user_func($this->callback[$this->nodeType][$this->name], $this);
}
}
}
/**
* Run XPath query on current node
*
* @param string $path
* @param string $version
* @param string $encoding
* @return array(SimpleXMLElement)
*/
public function expandXpath($path, $version = "1.0", $encoding = "UTF-8")
{
return $this->expandSimpleXml($version, $encoding)->xpath($path);
}
/**
* Expand current node to string
*
* @param string $version
* @param string $encoding
* @return SimpleXMLElement
*/
public function expandString($version = "1.0", $encoding = "UTF-8")
{
return $this->expandSimpleXml($version, $encoding)->asXML();
}
/**
* Expand current node to SimpleXMLElement
*
* @param string $version
* @param string $encoding
* @param string $className
* @return SimpleXMLElement
*/
public function expandSimpleXml($version = "1.0", $encoding = "UTF-8", $className = null)
{
$element = $this->expand();
$document = new DomDocument($version, $encoding);
$node = $document->importNode($element, true);
$document->appendChild($node);
return simplexml_import_dom($node, $className);
}
/**
* Expand current node to DomDocument
*
* @param string $version
* @param string $encoding
* @return DomDocument
*/
public function expandDomDocument($version = "1.0", $encoding = "UTF-8")
{
$element = $this->expand();
$document = new DomDocument($version, $encoding);
$node = $document->importNode($element, true);
$document->appendChild($node);
return $document;
}
}
?>
Two lines xml2array:
<?php
$xml = simplexml_load_string($xmlstring);
$array = (array) $xml;
?>