Phing

The other day I needed to copy a Drupal project from my source folder to another folder, so rather than manually copy the files I decided to create a Phing script that would do it for me in one go. This Phing script will export your Drupal project into another directory, change the database credentials and create zip and tar files of the project. The first thing to do is create a properties, here is the contents of that file.

When you run a phing script it will print things out to the console. These messages are either system messages (eg. BUILD STARTED) or echo messages that you have put into your build.xml file. All of this output is controlled and created by a logger file. The default logger is called (unsurprisingly) DefaultLogger and will be used as a default. There are a few different types of logger available, all of which can be found in the listener folder in your PEAR\phing directory.

To select a different logger script to be used just use the -logger flag in your phing call. To specify the DefaultLogger use the following:

phing -logger phing.listener.DefaultLogger

To specify an XML logger that will create an XML document of the phing events that occurred in the current working directory use the XmlLogger logger.

PHPUnit is a powerful unit testing framework written in and for PHP. Rather than testing everything as a whole the idea behind PHPUnit is to test that everything works as it is expected to work before it is integrated into the rest of the program. In this way problems are found earlier rather than later and this makes fixing them a lot easier. With tests written for every small component of the program it is then possible to test the whole thing by running all of the tests at once. It is also possible to automate PHPUnit so that everything about a program is tested before it is built. If any tests fail then the build is stopped.

The best way to install PHPUnit is to use the PEAR installer. To install PHPUnit you first need to add the correct channel so that PEAR can find PHPUnit easily. You do this by typing the following into the command line.

PHPUnit is a unit testing framework, written in PHP, and which is used to test PHP code. You can integrate the testing that PHPUnit does into Phing. You might want to use Phing to create a nightly build that contains the latest version of your program. The last thing you want is Phing to create a nightly build that is riddled with errors.

The way around this is to use PHPUnit to test our code whilst we are running Phing. If any tests fail then Phing will not finish the build.

Create a target at the top of your build.xml file and make sure it is run first. Then add the following code to the target, This will use PHPUnit to test your code.

Building your projects into directories is nice, but distributing these projects is difficult if you have to build the compressed files yourself. Phing has the ability to create zip and tar files using simple commands.

The most convenient way of using the tar and zip commands is by using a fileset. But rather than use the fileset that was used to copy the files into the build directory it is best to create a separate fileset that is used to compress the contents of the build directory.

After following the last post on deleting files and directories in Phing you might now be wondering if you can create things as well. The answer is yes.

To create a directory with Phing you need to use the mkdir element. The dir attribute is used to give the name of the directory to be created. The following example will create a directory called myProject_build in the current working directory (ie. where you are running phing from).

<mkdir dir="myProject_build" />

That is about as complicated as the mkdir element gets, although you can also pass a parameter to the dir attribute.

Although using Phing is mainly about copying files, you might also need to delete directories and files using the delete element. Remember that the default behavior of copy command copies files only if the source files are different from the destination files. A prudent approach might be to delete the build directory and then recreate it, ready for Phing to copy files into.

To delete a directory you need to use the dir attribute of the delete element, the delete element also accepts the file attribute to delete specific files. The following target will delete the directory myProject_build.

<target name="prepare">
<delete dir="myProject_build" />
</target>

The delete element can also accept a fileset element, which will delete multiple files. the following code will delete any php file from the myProject_build folder and from a sub folder called app.

The FilterChain element is where the power of Phing really comes into its own. This element will allow you to change the contents of the files of a fileset. This can range from a simple stripping of comments, to replacing values and numerous other filters.

One of the simplest thing that can be done with filterset is to strip all comments from the files in question. Take the following PHP file with two comments.

<?php
/**
 *
 * This is a comment
 *
 *
 **/
echo 'Hello World!';
 
// another comment.

These comments can be stripped out of the file by using the stripphpcomments element. This is added to the copy element in the following way.

Aside from assigning and using your own properties Phing also comes with a set of built in properties that can be used to find out all sorts of information regarding the system that Phing is run on.

As an example, let's say you wanted to found out the operating system that phing is being run on. In this case you would use the variable host.os, which on a Windows XP system would print out WINNT.

There are a lot of different properties available, so I have included the table from the phing website at the bottom of this post as a reference. However, there is one special variable called env that needs further explanation. The env variable references any environment variables that have been set. For example, if you set an environment variable using the following shell command (on UNIX based systems only).

export TESTVAR=mytestvar

You can now reference this in your build.xml file by using the following.

Phing allows you to set up certain parameters that can be used throughout the rest of the script. These might be used to define a non standard build directory, or to store database connection details that can be written to the connection file during the build.

Properties are defined using the property element, which you should place at the top of your build.xml file in order to make it easy for other developers to see what is going on. The following example defines a property and the uses the main target to print the property out.

<?xml version="1.0"?>
<!-- build xml -->
<project name="myProject" default="main">
 <property name="property1" value="value1" />
 
 <target name="main">
  <echo>property1: ${property1}</echo>
 </target>
</project>

Running this build.xml file will product the following result.