What is phpDocumentor? What can it do?

phpDocumentor is a tool written in PHP designed to create complete documentation directly from both PHP code and external documentation. The truth is, PHP source code is so lucid, it can practically serve as its own documentation. phpDocumentor taps into this fact by parsing out all kinds of logical structures already found in PHP, such as files, classes, functions, define constants, global variables, and class variables/methods and organizes them into a traditional manual format. In addition, new with version 1.3.0, source code elements introduced in PHP 5 (class constants, interfaces, and others) can also be parsed, if phpDocumentor is run through PHP 5. Output can be created for remote web browsing, print, and integration into IDE help systems through converters for HTML, PDF, and CHM (windows help files).

phpDocumentor generates manual-format documentation by reading it from special PHP comments called DocBlocks. DocBlocks are where you as the author of a software project should document helpful information that can be used by others (or your future self) to determine how to use and extend your PHP package.

Although the ability to add succinct documentation in the source code is essential, it cannot replace the importance of verbose documentation that is not in the source code, such as a user manual, or tutorials such as the one you are reading now. If the text you see here were placed in the source code for phpDocumentor, it would serve little useful purpose, clutter up the code, and be difficult to locate. However, the ability to hyperlink between documentation in the source code and external documentation is essential. External documentation for function foo must be able to reference the generated in-code documentation, and with phpDocumentor this is finally possible. To learn more, read about phpDocumentor Tutorials.

Installation

There are two official installation methods for phpDocumentor. The first is through downloading and extracting one of the available archives downloadable through pear.php.net and sourceforge.net, and the other is through the PEAR installer. There is planning for a Phing task and for distribution through other new and promising installation frameworks like the ZZ/OSS installer. However, only the two official installation methods are supported by phpDocumentor's developers.

Download from Pear.Php.net or Sourceforge.net

To install phpDocumentor from a .zip or tarball downloaded directly from pear.php.net or sourceforge.net, first determine whether you will be using phpDocumentor's web or command-line interface (see the Basic usage of phpDocumentor tool section for help in making this decision).

If you wish to use the command-line interface, unzip the archive into any directory, say /home/myuser/phpdoc or C:\Program Files\phpdoc, and add that directory to your path statement. To use, run the "phpdoc" command. In windows, you will need to edit the phpdoc.bat file, and change the first line to the path of the CLI version of PHP (usually C:\php4\cli\php.exe by default).

To use the web interface, you must have a web server such as Apache installed, and must have a working PHP sapi for that webserver. To test, save the code below as phpinfo.php in your document root and browse to http://localhost/phpinfo.php

phpinfo.php:

1. <?php
2. phpinfo();
3. ?>

If you see a beautiful purple display of PHP information, then your PHP setup is working. To use phpDocumentor's web interface, simply unzip the archive into a subdirectory of your document root (such as phpdoc) and browse to that location (http://localhost/phpdoc).

Installation through PEAR

To install phpDocumentor through PEAR, you must first have a working installation of PEAR. Instructions for properly installing PEAR are located at the official PEAR website, http://pear.php.net. phpDocumentor developers do not support installation issues with PEAR, instead seek help from PEAR developers.

Installing phpDocumentor for use on the command-line is simple. Simply run:

$ pear install PhpDocumentor
    

To install phpDocumentor to use the web interface, you must first change one of PEAR's configuration variables, data_dir, to be a sub-directory of your web server's document root. The simplest way to do this is through PEAR's command-line interface with the command:

$ pear config-set data_dir /path/to/document_root/pear
    

Configuring this value through the web interface is also simple. Click on the configuration icon in the left-hand frame, and type in the path in the data_dir text box.

Once this configuration is complete, simply install phpDocumentor as described in the second paragraph above, and you can then browse to http://localhost/pear/PhpDocumentor to have access to the web interface. Once this configuration step has been taken, there is never any need to change, and you can easily upgrade to future phpDocumentor versions by using pear's upgrade command.

How to document your code for use with phpDocumentor

Documenting your code projects is straightforward and intuitive for the most part. Before you begin, you may wish to download the sample documentation project and try running phpDocumentor on them as you read along, found at Source code for sample1.php, Source code for sample2.php, Source code for sample3.php or found bundled in the tutorials/ directory of your phpDocumentor distribution. Before parsing, copy the examples to another directory.

First of all, run phpDocumentor on the blank file sample1.php. If you are using the command-line interface, run this command from the tutorials/sample directory:

$ phpdoc -o HTML:frames:earthli -f sample1.php -t docs
    

If you are using the web interface, click the "Files" tab, and type in the full path to tutorials/sample/sample1.php. Then click the "Output" tab and type in the full path to tutorials/sample/docs, and finally click the "Create" button in the lower right-hand corner.

With a web browser, open the newly created tutorials/sample/docs/index.html file and you will see the rich array of information that phpDocumentor can parse from the source code even without any documentation comments. Inheritance information, polymorphism and constants are all recognized automatically. Note that the only element that is not automatically documented is the global variable - to do this, you must use a phpDocumentor DocBlock as described in the next section of this quickstart manual. Also note that although the include_once specifies a file within the include_path, phpDocumentor will not automatically parse sample2.php, you must manually specify the files or directories to parse.

If you're feeling adventurous, experiment with the parse options available and parse the sample files a few times to see how they affect the documentation output. To find out options in the command-line interface, type

$ phpdoc -h
   

Documenting your PHP source code with comments

Now open sample2.php. This is the same code content as sample1.php, but it contains a full array of phpDocumentor DocBlock comments. Note that every DocBlock comment is a C-style comment with two leading asterisks (*), like so:

1. /**
2.  *
3.  */

All other comments are ignored by the documentation parser. Note that although most of the documentation is plain English, there are a few "@" characters floating around the source code. This symbol is used to pass a special command to the parser, and is called a tag. If the symbol is at the beginning of a line, it is a standard tag, and if it is enclosed in {curly brackets}, it is an inline tag. You can read more about tags at phpDocumentor tags and phpDocumentor Inline tags.

1. /**
2.  * {@inlinetag} 
3.  * this is @not a standardtag - must begin a line.
4.  * this is a valid {@inlinetag} also
5.  * @standardtag
6.  */

Documenting global variables

Notice this code from sample2.php:

1. /**
2.  * Special global variable declaration DocBlock
3.  * @global integer $GLOBALS['_myvar'] 
4.  * @name $_myvar
5.  */ 
6. $GLOBALS['_myvar'] = 6;

In this segment, we can see the two important tags used for documenting global variables. The @global tag is used to tell the parser how to find a global variable declaration. Without this tag, no documentation would be generated for $_myvar. The @global tag can take many forms - be sure to specify the type and global name, with no description, or the parser will generate a warning and fail to document the variable.

Now, parse sample3.php and observe the generated documentation. The @name tag is used to tell the parser how the global variable would be referenced by a global statement in a function.

1. /**
2.  * @global integer this is a function-based @global tag,
3.  *          because the variable name is missing
4.  */
5. function someFunction()
6. {
7.     global $_myvar;
8. }

The @global tag here will associate the information with the declared global statements in the function body in the same order of their declaration.

Page-level DocBlock warnings

The single most commonly asked question about using phpDocumentor involves warnings about Page-level DocBlocks. This section will answer any questions about this warning once and for all.

phpDocumentor organizes procedural elements and classes into special groupings called packages. In earlier versions of phpDocumentor, if package was not specified explicitly using the @package tag, the program would make an educated guess as to which package a source element belongs to.

Over time, it became apparent that in many cases, source elements were incorrectly grouped into a package due to the guesswork phpDocumentor uses. Finally, the decision was made to require an explicit @package tag, and to raise a warning any time this tag was missing from a top-level source element.

The greatest confusion comes from the documenting of files. phpDocumentor documents all source elements by reading the DocBlock that immediately precedes the element, like so:

1. <?php
2. /**
3.  * Documents the class following
4.  * @package SomePackage
5.  */
6. class SomeClass {
7. }
8. ?>

phpDocumentor also can document the contents of a file. But how can a DocBlock immediately precede the file that contains it? The easy answer is to assume the first DocBlock in a file documents the file that contains it, and this works well, but can be deceptive:

1. <?php
2. /**
3.  * Documents the class following or the file?
4.  * @package SomePackage
5.  */
6. class SomeClass {
7. }
8. ?>

The same example shows the ambiguity - does this DocBlock document the class, or the file? To resolve this ambiguity, phpDocumentor uses a simple algorithm to make its decision.

1. If the first DocBlock in a file contains a @package tag, it documents the file unless it precedes a class declaration
   
2. If the first DocBlock in a file precedes another DocBlock, it documents the file
   

1. <?php
2. /**
3.  * This is a file-level DocBlock
4.  * 
5.  * A warning will be raised, saying that to document the define, use
6.  * another DocBlock
7.  * @package SomePackage
8.  */
9. define('foo', 'bar');
10. ?>

1. <?php
2. /**
3.  * This is a not a file-level DocBlock
4.  * 
5.  * A warning will be raised, saying that no file-level DocBlock is present
6.  * and this DocBlock will attach to the define statement
7.  */
8. define('foo', 'bar');
9. ?>

1. <?php
2. /**
3.  * This is a not a file-level DocBlock
4.  * 
5.  * A warning will be raised, saying that no file-level DocBlock is present
6.  * and this DocBlock will attach to the class statement
7.  */
8. class foo {}
9. ?>

1. <?php
2. /**
3.  * This is a not a file-level DocBlock, because it precedes a class declaration
4.  * 
5.  * A warning will be raised, saying that no file-level DocBlock is present
6.  * and this DocBlock will attach to the class statement
7.  * @package SomePackage
8.  */
9. class foo {}
10. ?>

1. <?php
2. /**
3.  * This is a file-level DocBlock
4.  * 
5.  * A warning will be raised saying that the package was assumed to be
6.  * SomePackage
7.  */
8. /**
9.  * This is a normal class-level DocBlock
10.  * 
11.  * this DocBlock will attach to the class statement
12.  * @package SomePackage
13.  */
14. class foo {}
15. ?>

1. <?php
2. /**
3.  * This is a file-level DocBlock
4.  * 
5.  * A warning will be raised saying that the package was assumed to be
6.  * SomePackage because no @package tag was used
7.  */
8. /**
9.  * This is a not a file-level DocBlock, because it precedes a class declaration
10.  * 
11.  * A warning will be raised, saying that no file-level DocBlock is present
12.  * and this DocBlock will attach to the class statement
13.  * @package SomePackage
14.  */
15. class foo {}
16. ?>

1. <?php
2. /**
3.  * This is a file-level DocBlock
4.  * 
5.  * No warning will be raised.  This is the recommended usage
6.  * @package SomePackage
7.  */
8. /**
9.  * This is a not a file-level DocBlock, because it precedes a class declaration
10.  * 
11.  * This is also the recommended usage
12.  * @package SomePackage
13.  */
14. class foo {}
15. ?>

Writing external documentation and linking to source code documentation

Although documentation parsed directly from source code is tremendously useful, it cannot stand on its own. In addition, truly useful in-code documentation must be succinct enough so that the code is not completely obscured by the documentation. External documentation is a must for a complete documentation solution. However, external documentation must be able to link to API source documentation to be useful. With a constantly changing API documentation, it is very easy for external documentation to become out of date. In addition, external documentation must be in a format that can be converted into other formats such as HTML, PDF and XML.

phpDocumentor provides a simple and elegant solution to all of these problems. External documentation in DocBook format can be easily converted to other formats. Using inline tags, phpDocumentor can generate a consistent manual in many different formats by combining the output from parsing the source and parsing external documentation. The words you read at this moment are in a DocBook-based file located in tutorials/phpDocumentor/phpDocumentor.quickstart.pkg

1. <refentry id="{@id}">
2.  <refnamediv>
3.   <refname>Simple Tutorial</refname>
4.   <refpurpose>The simplest Tutorial Possible</refpurpose>
5.  </refnamediv>
6.  <refsynopsisdiv>
7.   <author>
8.    Gregory Beaver
9.    <authorblurb>
10.     {@link mailto:cellog@php.net cellog@php.net}
11.    </authorblurb>
12.   </author>
13.  </refsynopsisdiv>
14.  <refsect1 id="{@id intro}">
15.   <para>Hello World</para>
16.  </refsect1>
17. </refentry>

Basic usage of phpDocumentor tool

Now that phpDocumentor is installed, how can you use it to document a project? First, you must understand how phpDocumentor divides your code into packages and subpackages. If you haven't already, now would be a good time to read the How to document your code for use with phpDocumentor section of this quickstart.

Command-line tool, phpdoc

docbuilder, the phpDocumentor web interface