IT. Expert System.

PHP

Basic SimpleXML usage


Basic SimpleXML usage

Many examples in this reference require an XML string. Instead of repeating this string in every example, we put it into a file which we include in each example. This included file is shown in the following example section. Alternatively, you could create an XML document and read it with simplexml_load_file().

Example #1 Include file example.php with XML string

<?php
$xmlstr 
= <<<XML
<?xml version='1.0' standalone='yes'?>
<movies>
 <movie>
  <title>PHP: Behind the Parser</title>
  <characters>
   <character>
    <name>Ms. Coder</name>
    <actor>Onlivia Actora</actor>
   </character>
   <character>
    <name>Mr. Coder</name>
    <actor>El Act&#211;r</actor>
   </character>
  </characters>
  <plot>
   So, this language. It's like, a programming language. Or is it a
   scripting language? All is revealed in this thrilling horror spoof
   of a documentary.
  </plot>
  <great-lines>
   <line>PHP solves all my web problems</line>
  </great-lines>
  <rating type="thumbs">7</rating>
  <rating type="stars">5</rating>
 </movie>
</movies>
XML;
?>

The simplicity of SimpleXML appears most clearly when one extracts a string or number from a basic XML document.

Example #2 Getting <plot>

<?php
include 'example.php';

$movies = new SimpleXMLElement($xmlstr);

echo 
$movies->movie[0]->plot;
?>

The above example will output:

  So, this language. It's like, a programming language. Or is it a scripting language? All is revealed in this thrilling horror spoof of a documentary. 

Accessing elements within an XML document that contain characters not permitted under PHP's naming convention (e.g. the hyphen) can be accomplished by encapsulating the element name within braces and the apostrophe.

Example #3 Getting <line>

<?php
include 'example.php';

$movies = new SimpleXMLElement($xmlstr);

echo 
$movies->movie->{'great-lines'}->line;
?>

The above example will output:

 PHP solves all my web problems 

Example #4 Accessing non-unique elements in SimpleXML

When multiple instances of an element exist as children of a single parent element, normal iteration techniques apply.

<?php
include 'example.php';

$movies = new SimpleXMLElement($xmlstr);

/* For each <character> node, we echo a separate <name>. */
foreach ($movies->movie->characters->character as $character) {
   echo 
$character->name' played by '$character->actorPHP_EOL;
}

?>

The above example will output:

 Ms. Coder played by Onlivia Actora Mr. Coder played by El ActÓr 

Note:

Properties ($movies->movie in previous example) are not arrays. They are iterable and accessible objects.

Example #5 Using attributes

So far, we have only covered the work of reading element names and their values. SimpleXML can also access element attributes. Access attributes of an element just as you would elements of an array.

<?php
include 'example.php';

$movies = new SimpleXMLElement($xmlstr);

/* Access the <rating> nodes of the first movie.
 * Output the rating scale, too. */
foreach ($movies->movie[0]->rating as $rating) {
    switch((string) 
$rating['type']) { // Get attributes as element indices
    
case 'thumbs':
        echo 
$rating' thumbs up';
        break;
    case 
'stars':
        echo 
$rating' stars';
        break;
    }
}
?>

The above example will output:

 7 thumbs up5 stars 

Example #6 Comparing Elements and Attributes with Text

To compare an element or attribute with a string or pass it into a function that requires a string, you must cast it to a string using (string). Otherwise, PHP treats the element as an object.

<?php
include 'example.php';

$movies = new SimpleXMLElement($xmlstr);

if ((string) 
$movies->movie->title == 'PHP: Behind the Parser') {
    print 
'My favorite movie.';
}

echo 
htmlentities((string) $movies->movie->title);
?>

The above example will output:

 My favorite movie.PHP: Behind the Parser 

Example #7 Comparing Two Elements

Two SimpleXMLElements are considered different even if they point to the same element since PHP 5.2.0.

<?php
include 'example.php';

$movies1 = new SimpleXMLElement($xmlstr);
$movies2 = new SimpleXMLElement($xmlstr);
var_dump($movies1 == $movies2); // false since PHP 5.2.0
?>

The above example will output:

 bool(false) 

Example #8 Using XPath

SimpleXML includes built-in XPath support. To find all <character> elements:

<?php
include 'example.php';

$movies = new SimpleXMLElement($xmlstr);

foreach (
$movies->xpath('//character') as $character) {
    echo 
$character->name'played by '$character->actorPHP_EOL;
}
?>

'//' serves as a wildcard. To specify absolute paths, omit one of the slashes.

The above example will output:

 Ms. Coder played by Onlivia Actora Mr. Coder played by El ActÓr 

Example #9 Setting values

Data in SimpleXML doesn't have to be constant. The object allows for manipulation of all of its elements.

<?php
include 'example.php';
$movies = new SimpleXMLElement($xmlstr);

$movies->movie[0]->characters->character[0]->name 'Miss Coder';

echo 
$movies->asXML();
?>

The above example will output:

 <?xml version="1.0" standalone="yes"?> <movies> <movie> <title>PHP: Behind the Parser</title> <characters> <character>  <name>Miss Coder</name>  <actor>Onlivia Actora</actor> </character> <character>  <name>Mr. Coder</name>  <actor>El Act&#xD3;r</actor> </character> </characters> <plot> So, this language. It's like, a programming language. Or is it a scripting language? All is revealed in this thrilling horror spoof of a documentary. </plot> <great-lines> <line>PHP solves all my web problems</line> </great-lines> <rating type="thumbs">7</rating> <rating type="stars">5</rating> </movie> </movies> 

Example #10 Adding elements and attributes

Since PHP 5.1.3, SimpleXML has had the ability to easily add children and attributes.

<?php
include 'example.php';
$movies = new SimpleXMLElement($xmlstr);

$character $movies->movie[0]->characters->addChild('character');
$character->addChild('name''Mr. Parser');
$character->addChild('actor''John Doe');

$rating $movies->movie[0]->addChild('rating''PG');
$rating->addAttribute('type''mpaa');

echo 
$movies->asXML();
?>

The above example will output:

 <?xml version="1.0" standalone="yes"?> <movies> <movie> <title>PHP: Behind the Parser</title> <characters> <character>  <name>Ms. Coder</name>  <actor>Onlivia Actora</actor> </character> <character>  <name>Mr. Coder</name>  <actor>El Act&#xD3;r</actor> </character> <character><name>Mr. Parser</name><actor>John Doe</actor></character></characters> <plot> So, this language. It's like, a programming language. Or is it a scripting language? All is revealed in this thrilling horror spoof of a documentary. </plot> <great-lines> <line>PHP solves all my web problems</line> </great-lines> <rating type="thumbs">7</rating> <rating type="stars">5</rating> <rating type="mpaa">PG</rating></movie> </movies> 

Example #11 DOM Interoperability

PHP has a mechanism to convert XML nodes between SimpleXML and DOM formats. This example shows how one might change a DOM element to SimpleXML.

<?php
$dom 
= new DOMDocument;
$dom->loadXML('<books><book><title>blah</title></book></books>');
if (!
$dom) {
    echo 
'Error while parsing the document';
    exit;
}

$books simplexml_import_dom($dom);

echo 
$books->book[0]->title;
?>

The above example will output:

 blah 



Content

Android Reference

Java basics

Java Enterprise Edition (EE)

Java Standard Edition (SE)

SQL

HTML

PHP

CSS

Java Script

MYSQL

JQUERY

VBS

REGEX

C

C++

C#

Design patterns

RFC (standard status)

RFC (proposed standard status)

RFC (draft standard status)

RFC (informational status)

RFC (experimental status)

RFC (best current practice status)

RFC (historic status)

RFC (unknown status)

IT dictionary

License.
All information of this service is derived from the free sources and is provided solely in the form of quotations. This service provides information and interfaces solely for the familiarization (not ownership) and under the "as is" condition.
Copyright 2016 © ELTASK.COM. All rights reserved.
Site is optimized for mobile devices.
Downloads: 360 / 96392414. Delta: 0.04659 с