Here is one more sample chapter from my book. It explains reading, writing and editing XML files with PHP and jQuery. Below are the chapter contents.

• Loading XML from files and strings using SimpleXML
• Accessing elements and attributes using SimpleXML
• Searching elements using XPath
• Reading an XML using DOM extension
• Creating an XML using DOM extension
• Modifying an XML using DOM extension
• Parsing XML with jQuery

To read the full chapter follow this link - https://www.packtpub.com/article/working-with-xml-documents

You can also read the chapter on using JSON with PHP and jQuery.

Yes that’s right and it is called PHP jQuery Cookbook.  As the name suggests, it’s about creating rich internet applications using 2 of my favorite technologies – PHP and jQuery.

I love coding web apps and helping others find solutions. Perhaps that is the reason I agreed to write when the wonderful people at Packt Publishing contacted me. (Also, a book on resume isn’t that bad either )

Another reason is I love Open source. It is a lovely philosophy and I am a strong believer in it. Having learnt so much from the Open source community since I started coding, I have always wanted to return something back. Nothing could have been better then this. And did I mention, Packt pays direct royalty to a project if they sell a book written on the same.

Long story short, the book is cookbook with around 65 recipes covering PHP, jQuery, MySql and some API’s (Flickr, Youtube).

Structure wise, it has 10 chapters in all.

• Handling Events
• Combining PHP and jQuery
• Working with XML documents
• Working with JSON
• Working with Forms
• Adding Visual effects to forms
• Creating cool Navigation Menus
• Data binding with PHP and jQuery
• Enhancing your site with PHP and jQuery
• Appendix – FireBug

The book is available now will be available by 14th December Christmas this year or January next year. You can have a look in detail about what it is all about on Packt Website. Order a copy in case you find it interesting

In this tutorial you will learn how to create XML documents using PHP’s DOMDocument class.

First things first.There are 3 things that you should always keep in mind about XML. In short, XML has 3 main components.

1. Elements, which we also call nodes. e.g.

2. Attributes e.g

   Here type is an attribute.

3. Data/text nodes

   Johnson

   Here “first” and “Johnson” are text nodes.

Hope this is clear. Now, we will create the following XML from our code.

<?xml version="1.0" encoding="utf-8"?>

100 grams
43
3.2 grams

Recently, I have become too much conscious(obsessed!!!) about calories, fat and protein. Hence this XML. Never mind, let us jump to code now.

First of all we will create an empty xml doxument. Then we will append nodes to it as required.

    $objXML = new DOMDocument('1.0','utf-8');    

This is constructor of DOMDocument class which defines an XML document. It will create an empty xml document. 1.0 is version and utf-8 is encoding of resulting xml. Second parameter is optional.

Total 4 functions will be used to create the xml.

1. createElement: used to create xml nodes.
2. createAttribute: used to create attributes of a node.
3. createTextNode: used to create text nodes or createCDATASection if you want cdata sections instead of text nodes.
4. appendChild: this will append above mentioned elements to xml.

First, let us create our root node fruit with attribute name=apple.

$fruit = $objXML->createElement("fruit");
$objXML->appendChild($fruit);
$fruitName = $objXML->createAttribute("name");
$fruitName->appendChild($objXML->createTextNode("Apple"));
$fruit->appendChild($fruitName);

Line 1 creates an element named fruit. Line 2 appends fruit to xml document. Line 3 creates an attribute called name. Line 4 sets the value of attribute name to “Apple” and finally line 5 appends this attribute to fruit element.

To see this xml write the following.

echo $objXML->saveXML(); 

This will create following xml:

Looks good. XML with an empty node fruit has been created(If xml is not visible in your browser, view the source of page). Now all we have to do is create elements weight, calories, protein, fat and append them to parent node fruit. Lets do it.

//create element weight
$weight = $objXML->createElement("weight");

//append text to it by creating a text node inside it
//you can use createCDATASection if you need it
$weight->appendChild($objXML->createTextNode("100 grams"));

//append newly created weight node to fruit node
$fruit->appendChild($weight);

Comments aboveare self explanatory. Now repeat the same procedure to create remaining nodes.

//create element calories
$calories = $objXML->createElement("calories");

//append text to it by creating a text node inside it
$calories->appendChild($objXML->createTextNode("43"));

//append newly created calories node to fruit node
$fruit->appendChild($calories);

//create element protein
$protein = $objXML->createElement("protein");

//append text to it by creating a text node inside it
$protein->appendChild($objXML->createTextNode("3.2 grams"));

//append newly created calories node to fruit node
$fruit->appendChild($protein);

Note: Weight, calories and protein nodes are identical. Above is only an example. However, in real world scenes, you should create a function to avoid duplication of code.

All done. Only thing thing remaining is saving this XML. There are 2 ways to do this.

 echo $objXML->saveXML(); 

will return a string containing created xml.

 $objXML->save('someName.xml'); 

will save the xml to someName.xml file.

Resulting xml will be

<?xml version="1.0" encoding="utf-8"?>

100 grams
43
3.2 grams

This is it for now. Complete source code is available at this link. If you are thinking why we wrote 16 lines of code to generate a 5 line xml, think again. In next post I will show you how can you create large xmls (say of 500 lines ) with 25 lines of code.
Do let me know if you have any queries.

Applies to:  simplexml_load_string and simplexml_load_file

Problem : SimpleXML does not parse text inside CDATA tags in an XML.

Consider the XML below:

$str = '';
$str.='some text goes here';
$str.='';

To parse it we use following syntax:

$xml = simplexml_load_string($str);

On printing it outputs:

SimpleXMLElement Object
(
    [childNode] => some text goes here
)

Thats OK. Now the same xml but this time the text is enclosed in CDATA tags.

$str = '';
$str.='';
$str.=''

On printing this gives following output:

SimpleXMLElement Object
(
    [childNode] => SimpleXMLElement Object
        (
        )

)

Yes its empty. This is because SimpleXML does not parse CDATA tags. All data enclosed within CDATA is ignored by SimpleXML parser.

Solution: Set the 3rd parameter to LIBXML_NOCDATA while parsing.

simplexml_load_string(simplexml_load_file too) actually takes 3 parameters.

• The string to parse
• Optional parameter – to return an object of class specified in this parameter. (By default it returns a SimpleXMLElement Object)
• Also optional – libxml parameters can be specified as options. This option provides the solution to our CDATA problem

Provide the 3rd parameter LIBXML_NOCDATA and SimpleXML will consider CDATA nodes as text nodes and will parse them.

$xml = simplexml_load_string($str,'SimpleXMLElement', LIBXML_NOCDATA);

This will output as desired:

SimpleXMLElement Object
(
    [childNode] => some text goes here
)

Please note that using the third parameter requires PHP >=5.1 compiled with libxml.

I will be publishing a new post shortly on how to use SimpleXML to parse xml and extract data.