Here is a short tutorial about my discovery of the new YAML parsing library that comes with symfony 1.1. As you may know, YAML files are a place symfony developers spend time writing configuration, it is very important they have a good tool to manipulate data and debug files.

They include code showing how to pull in a sample file, access the properties inside of it and how to take a multi-dimensional PHP array and push it back out (automagically) into a new YAML formatted file.

If you use YAML in PHP, then you had until recently the choice between the C based PECL extension syck or the horrible spyc PHP based implementation. With syck it has the issue that it only supports the core standard and not stuff like merge-key, which is a very very useful extension to the core YAML standard.

He also points out another implementation that the Symfony framework has created - one built around regular expressions (slower, but a "more correct" version).

I've been going through all those open source projects and cutting the dead weight. [...] One of the victims of this review has been Zend_Yaml. Earlier this morning I found an odd comment on the Zend_Translate_Yaml proposal by Thomas Weidner that he was erasing his proposal on the basis that there had been no progress on Zend_Yaml.

He's removed the proposal from the Zend Framework proposal pages after receiving an email noting that the package would not comply fully to the YAML 1.1 specification and couldn't be included. With the introduction of the Syck extension into PECL, it could support it but Padraic opted to just tell the ZF group about this functionality rather than working on the build himself.

YAML, or YAML Ain't Markup Language, is a "human friendly data serialization standard". It's essentially a very basic format for storing data, and uses far less syntax than standard PHP. [...] It's almost like English; it's as basic as you want. Of course, that's not to say it doesn't support complex structures - this example demonstrates the power of the format.

He also points out the spyc extension that makes working with the files in PHP a breeze.

This is the package's first stable release. Chuck Hagenbuch started the library as an adaptation of Spyc around six months ago. Since then, he and I have been quietly using and improving it. Along the way, we fixed many issues, added support for pecl/syck, and wrote a test suite with PHPUnit.

You can find the latest download of the package over on the Horde PEAR channel and you can find out more about the YAML (YAML Ain't Markup Language) spec over on the Yaml.org website.

Besides PHP itself, the most popular config file formats for PHP applications are INI and XML files. [...] YAML is a relatively new format that has been pioneered by the Ruby and Rails communities. It blends the best aspects of XML and INI, giving us a format with the flexibility of XML and the ease-of-use of INI.

He compares the YAML support - Ruby's built-in support and PHP's functionality via either the Spyc library/Syck extension or through a PEAR package from the Horde functionality. Quick code snippets are provided for each.

Today we will talk about migrations, yaml files and CakePHP and in particular I'll introduce you to the latest shell I've written for CakePHP: YAMMY! I've written YAMMY! a couple of weeks ago, but I just found the time to release it today. Anyway lets get into more details!

The author, Daniel Vecchiato, first explains what migrations are and how they relate to database tables (like revision control - sort of). A previous project made it possible to do migrations in CakePHP, but it lacked what he calls the "right food" to get it working as well as it could. That's where YAMMY! comes in - by answering a few simple questions, you can set up a YAML record of your database tables and make it simple to integrate into your application's development process.

I've just released syck for php 0.9.2 (a parser and emitter of YAML documents. If you don't know anything about YAML and why it is good: check my previous posts on the subject). A lot of new and tasty features.

Updates he mentions include:

• stability and consistency fixes
• enhancements with object-serialization and unserialization
• loading of objects more class names

I have always disliked creating configuration data by reading from various formats into global arrays, so I needed to build or borrow a configuration class for my own projects that I could standardize on.

He discusses the base he worked from - a class based on the Zend_Config package in the Zend Framework, using his own sort of caching scheme. He's also included the code to see it in action (including the code download).

If you've ever encountered the same need, or if you're just curious about the YAML format and how it can be used with PHP, then today is your lucky day. Over the next few pages, I'm going to give you a crash course in YAML and in PHP's ext/syck extension, showing you how it can be used to efficiently translate data structures from PHP to YAML, and vice-versa. Come on in, and let's get started!

The tutorial starts with an example of a YAML file before getting into the application portion. He shows how to grab the Syck extension, install it, create a simple YAML file and create a configuration file (and parser) for a simple form application.