This is a plugin designed to make JAXB possible and easy in PHP.
JAXB is a Java Architecture for XML Binding. As you can guess, it is native to the Java language. It is an alternative method for parsing XML documents from other techniques like DOM or SAX. There are two key steps in JAXB:
1. Creating classes from an XML Schema
2. Instantiating those classes using data from XML
By passing in the file path to an XML Schema, our JAXB plugin will read through the schema and pick out all the element definitions which have child elements. These are the XML elements which we will want to create into objects. Any SimpleTypes we can ignore. After that, it's a simple matter of creating a class file with the element's name, and assigning it attributes for every child element. Luckily PHP is a loosly-typed language, so we don't have to worry about data types. fist pound.
Running the parseSchema method on a schema file will create a bunch of class files and stick them in the classes directory. If the classes directory doesn't exist, it will make one for you. The naming convention for class files is (using a class called 'Name' as an example) Name.class.php.
Next, we pass into the plugin the file path to an XML document using the unmarshal function. The plugin will then read through the XML file, creating objects and setting attributes when necessary. This plugin includes both XML attributes and child nodes as class properties. If the class property originated as an XML attribute, it will have an underscore before its name.
Example:
<Company ID="2342" Name="Apple, Inc.">
<Street>1 Infinite Loop</Street>
<City>Cuppertino</City>
<State>California</State>
<Leader>Tim Cook</Leader>
</Company>
Will produce the following object:
class Company
{
private $_ID = "2342";
private $_Name = "Apple, Inc.";
private $Street = "1 Infinite Loop";
private $City = "Cuppertino";
private $State = "California";
private $Leader = "Tim Cook";
}
The script will also produce appropriate accessors and mutators, for instance setName and getID for the above example. I also added in a hasAttribute method which uses the property_exists PHP method, returning a boolean. Since the accessors and mutators ignore the underscore, you don't have to worry about it. It would just be used for reading in and out XML data, and if you wanted to modify the class file yourself. That's what's awesome about this technique, it creates iterable objects which you can modify and fine tune yourself.
## Note:
Since there is no way of checking if a property has an underscore after you unmarshal the data, use the `hasAttribute` method. This returns back `true` if the attribute exists and has an underscore, `false` if it doesn't exist or does not have an underscore.
The output from reading in an XML file is one large object, with nested objects within it representing the XML document tree.
Once you are done playing with your new object, use the marshal function to turn it back into XML. The marshal function takes in:
1. The object you want to transform
2. [Optional] The filename to save the outputted XML. This is optional because if you do not pass one in, JAXB will write over the last file you read in. If you did not previously read in any files, the function will fail and return `false`.
- JAXB.class.php -- converts a schema into class files, converts an XML document into an object, converts an object into an XML document.
- classes -- folder holds all the outputted class files
- sample.xml -- test input xml document
- sample.xsd -- test input schema
- test.php -- our main script