DocBlox ... use to generate API documentation in PHP

Using DocBlox

Until a few years ago, there were basically two tools you could use to generate API documentation in PHP: phpDocumentor and Doxygen. phpDocumentor was long considered the standard, with Doxygen getting notice when more advanced features such as inheritance diagrams are required. However, phpDocumentor is practically unsupported at this time (though a small group of developers is working on a new version), and Doxygen has never had PHP as its primary concern. As such, a number of new projects are starting to emerge as replacements.

One of these is DocBlox. I am well aware there are several others -- and indeed, I've tried several of them. This post is not here to debate the merits or demerits of this or other solutions; the intention is to introduce you to DocBlox so that you can evaluate it yourself.

Getting DocBlox

DocBlox can be installed in a variety of ways:

• You can checkout the project via GitHub.
• You can download a snapshot.
• You can download a release.
• You can use use the PEAR installer.

I personally prefer using the PEAR installer, as it's as simple as this:

prompt> pear channel-discover pear.michelf.com
prompt> pear channel-discover pear.docblox-project.org
prompt> pear install -a docblox/DocBlox-beta

The first channel-discover is to grab a third-party package optionally used in the rendering process to convert Markdown in the descriptions to HTML. And don't let the "beta" status fool you -- this project is quite stable at this point; the author, Mike van Riel, is simply being conservative as he rounds out features.

If you are checking out the project via Git or a snapshot, you simply need to expand the archive and make a note of its location -- when I've used this method in the past, I usually create a symlink to the bin/docblox.php script in my path:

prompt> ln -s path/to/docblox/bin/docblox.php ~/bin/docblox

Using DocBlox

Once you have installed DocBlox, how do you use it? It's really quite easy:

prompt> cd some/project/of/yours/
prompt> mkdir -p documentation/api/
prompt> docblox run -d path/to/source/ -t documentation/api/

At this point, DocBlox will merrily scan your source located in path/to/source, and build API documentation using its default HTML templates for you in documentation/api. Once complete, you can point your browser at documentation/api/index.html and start browsing your API documentation.

Using DocBlox to identify missing docblocks

While running, you may see some notices in your output stream, like the following:

2011-08-02T16:08:34-05:00 ERR (3): No DocBlock was found for Property $request in file Mvc/Route/RegexRoute.php on line 16

This output is invaluable for identifying places you've omitted docblocks in your code. You can capture this information pretty easily using tee:

prompt> docblox run -d path/to/source/ -t documentation/api/ 2>&1 | tee -a docblox.log

I recommend doing this whenever running DocBlox, going through the output, and adding docblocks wherever you encounter these errors.

(You can do similarly using tools such as PHP_CodeSniffer. More tools is never a bad thing, though.)

If you want to disable the verbosity, however, you can, by passing either the -q or --quiet options.

Class Diagrams

DocBlox will try and generate class diagrams by default. In order to do this, you need to have GraphViz installed somewhere on your path. The results are pretty cool, however -- you can zoom in and out of the diagram, and click on classes to get to the related API documentation.

(The class diagram is typically linked from the top of each page.)

Specifying an alternate title

By default, DocBlox uses its own logo and name as the title of the documentation and in the "header" line of the output. You can change this using the --title switch:

prompt> docblox run -d path/to/source/ -t documentation/api/ --title \"My Awesome API Docs\"

Using alternate templates

While the default template of DocBlox is reasonable, one of its initial selling points to me was the fact that you could conceivably create new templates. In order to test this out, and also iron out some of the kinks, Mike wrote templates for a few PHP OSS projects, including Zend Framework and Agavi. Templates need to be in a location DocBlox can find them -- in DocBlox/data/themes under your PEAR install, or simply data/themes if you installed a release tarball. Invoking a theme is as easy as using the --template argument:

prompt> docblox run -d path/to/source/ -t documentation/api/ --title \"My Awesome API Docs\" --template zend

Try out each of the provided themes to see which you might like best -- and perhaps try your hand at writing a theme. Each given theme is simply an XML file and a small set of XSL stylesheets, and optionally CSS and images to use with the generated markup.

Iterative documentation

When you generate documentation, DocBlox actually creates a SQLite database in which to store the information it learns while parsing your code base. This allows it to be very, very fast both when parsing (it can free information from memory once it's done analyzing a class or file) as well as when transforming into output (as it can iteratively query the database for structures).

What does this mean for you?

Well, first, if you want to try out new templates, it won't need to re-parse your source code -- it simply generates the new output from the already parsed definitions. This can be very useful particularly when creating new templates. Generation is oftentimes instantaneous for small projects.

Second, it means that you can build the full documentation once, and only periodically update it (which you can do using the --force option). This is particularly useful for build processes.

Configuration

One problem with any rich CLI tool is that you often get a proliferation of options, and remembering them between invocations can be hard (particularly if you only run the tool during releases). DocBlox allows you to create a configuration file, docblox.xml, in your project. The format is relatively simple; the (mostly) equivalent to the above options I've used is as below:

<?xml version=\"1.0\" encoding=\"UTF-8\" ?>                                     
<docblox>
    <parser>
        <target>documentation/api</target>
    </parser>
    <transformer>
        <target>documentation/api</target>
    </transformer>
    <files>
        <directory>path/to/source</directory>
    </files>
    <transformations>
        <template>
            <name>zend</name>
        </template>
    </transformations>
</docblox>

You can't specify the title in the configuration, but often that will be template-driven, anyways.

DocBlox will then look for this file in the current directory and simply use it, allowing you to invoke it as follows:

prompt> docblox run

Or you can specify the configuration file yourself:

prompt> docblos run -c config.xml

(Side note: on the release current as of when I write, 0.12.2, I have not successfully been able to specify the template name.)

Search

If you look carefully at the generated output, you'll notice a search box. By default, this doesn't work... because it points to a PHP script! When installed on a server capable of serving PHP, however, it can be used to help find classes, methods, and more. As an example, you can search the Zend Framework 1.11 API documentation.

Conclusions

Hopefully this tutorial will get you started investigating DocBlox. I've been quite happy with what I've seen so far of the project, and gladly recommend it. There are other alternatives, however, and I also suggest you try those out; Liip recently published a comparison of features, and that article can be used as a starting point for your own investigations.

(Disclosure : Mike van Riel, he's developed DocBlox).