An Intro to Phing

What is Phing

Phing is a build system for php projects, like Ant is for java. Moreover phing is based on Apache Ant. Like any traditional build systems you can do a lot of things with Phing. Phing uses XML build files similar to ant build files. Phing is useful in cases where you have to write custom scripts for testing, packaging and deploying your application code. Phing provides a number of built in tasks or operational modules, and it also allows you to add custom tasks as per your need.

In short Phing provides the following features:

• Simple XML buildfiles
• Rich set of provided tasks
• Easily extendable via PHP classes
• Platform-independent: works on UNIX, Windows, MacOSX
• No required external dependencies

How Phing Works

Phing uses XML buildfiles, these buildfiles contain a description of the things to do. A buildfile contains one or more targets. These targets contain the actual commands to execute or perform (e.g. create a directory, delete a directory, copy a file from one directory to another, create a archive file etc.). In order to use Phing, you need to write a buildfile first and then you need to run phing, specifying the target in your buildfile that you want to execute.

$ phing [-f buildfile.xml] [target]

If name of a buildfile is not given, then Phing will search for a file name build.xml in the directory from where the Phing command is run. You can also define default target in your buildfile. In that case you can skip the target also while executing the phing command.

Installation

Phing requires PHP version 5.2 or above compiled with --with-libxml2 at minimum. For advanced usage of Phing you may need other libararies and softwares. For a detailed list of dependencies you can visit this page.

The easiest way to install phing is by using the PEAR installer. Just run the following commands from the command line:
$ pear channel-discover pear.phing.info
$ pear install phing/phing

A sample Phing build file:

Given below is a small simple build file that I used for one of my projects. I have added comments before each line or section to explain what is that doing.

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

<!-- project is the root element, a buildfile shoud start with project tag after the document prolog  -->
<!-- name : name of the project -->
<!-- basedir : the base project directory -->
<!-- default : the default target to build if phing is executed without specifying any target -->

<project name="applyservice" basedir="." default="main">

    <!-- define some project properties like package name, build directory and source directory -->
    <property name="package"  value="${phing.project.name}" override="true" />
    <property name="builddir" value="./build/" override="true" />
    <property name="srcdir"   value="${project.basedir}" override="true" />

    <!-- You can define set of all files to include/exclude in the build, give fileset an id for later reference -->
    <fileset dir="${srcdir}" id="allfiles">
        <include name="**/*.php" />
        <include name="**/*.yml" />
        <exclude name="**/*.log" >
    </fileset>

    <!-- Target: prepare, this will create a build directory if not already there -->
    <target name="prepare" description="initial setup">
        <echo msg="Creating build directory....." />
        <mkdir dir="./build" />
    </target>

    <!-- Target: main, Its our default target as defined in project tag -->
    <!-- A target can depend on other targets. You can define dependencies using depends attribute -->
    <!-- Our main target is dependent on prepare target to complete first -->
    <!-- You can define multiple targets in depends attribute using a comma separated list like A, B, C -->

    <target name="main" description="main target" depends="prepare">
        <echo msg="Copying files to build directory..." />
        <!-- copy all source files from the fileset defined above to the build directory -->
        <copy todir="${builddir}">
            <fileset refid="allfiles" />
        </copy>
       
        <!-- create a archive file of all the files in build directory using gzip compression -->
        <echo msg="Creating archive from build..." />
        <tar destfile="./build/build.tar.gz" compression="gzip">
            <fileset dir="./build">
                <include name="**" />
            </fileset>
        </tar>

        <echo msg="Build completed successfully........" />
    </target>

    <!-- Traget: rebuild, this target is for rebuilding, its first deletes previously build files and creates a new one by calling main target. -->
    <target name="rebuild" description="rebuilds this package">
    <echo msg="Deleting old build directory........" />
        <delete dir="${builddir}" />
        <phingcall target="main" />
    </target>
</project>

For a detailed list of all available options. Please go through the Phing User Guide.