Sample PHP classes generator

Given the following format of XML :

<?xml version="1.0" encoding="utf-8"?>
<classes>
    <class id="Name_Of_The_Class">
        <parent>
            <class id="Name_Of_The_Parent_Class"/>
        </parent>
    </class>
</classes>

Where:

The tag classes contains of collection of one or more class tags.

The attribute id of the class is the name of this class.

The parent tag is optional. If present it must contain the class tag with the attribute id defining the name of the parent class.

Our goal is to create an application capable of generating PHP code from such a XML definition. Therefore we need to create a piece of code which can be used for several use cases around this XML to PHP transformation.

Use Case 1

Create a PHP program (to be launched from the command line) which takes as input the name of a XML file, reads the specified file and outputs the number of classes defined in the XML file.

When running your program against the provided sample1.xml file, the expected result is: 4.

Use Case 2

Create a PHP program (to be launched from the command line) which takes as input a XML file, reads the specified file and outputs a PHP file containing a valid PHP declaration of all the classes defined in the given XML file.

Run your program against the provided sample1.xml and check that the result is a valid PHP file.

Example:

For example, the following XML:

<?xml version="1.0" encoding="utf-8"?>
<classes>
    <class id="MyClass1"/>
    <class id="MyClass2">
        <parent>
            <class id="MyClass1"/>
        </parent>
    </class>
</classes>

Must produce the following PHP:

<?php
class MyClass1
{
}
class MyClass2 extends MyClass1
{
}

Evaluation

On top of the actual result when running the code, the quality of the code (clarity, maintainability, testability...) is very important for this exercice.