This book is about Symfony YAML, a PHP library part of the Symfony Components project. Its official website is at http://components.symfony-project.org/yaml/.
SIDEBAR About the Symfony Components
Symfony Components are standalone PHP classes that can be easily used in any PHP project. Most of the time, they have been developed as part of the Symfony framework, and decoupled from the main framework later on. You don’t need to use the Symfony MVC framework to use the components.
Symfony YAML is a PHP library that parses YAML strings and converts them to PHP arrays. It can also converts PHP arrays to YAML strings.
YAML, YAML Ain’t Markup Language, is a human friendly data serialization standard for all programming languages. YAML is a great format for your configuration files. YAML files are as expressive as XML files and as readable as INI files.
There is only one archive to download, and you are ready to go. No configuration, No installation. Drop the files in a directory and start using it today in your projects.
Released under the MIT license, you are free to do whatever you want, even in a commercial environment. You are also encouraged to contribute.
Symfony YAML was initially released as part of the symfony framework, one of the most popular PHP web framework. It is also embedded in other popular projects like PHPUnit or Doctrine.
Symfony YAML is fully documented, with a dedicated online book, and of course a full API documentation.
One of the goal of Symfony YAML is to find the right balance between speed and features. It supports just the needed feature to handle configuration files.
The library is fully unit-tested. With more than 400 unit tests, the library is stable and is already used in large projects.
It sports a real parser and is able to parse a large subset of the YAML specification, for all your configuration needs. It also means that the parser is pretty robust, easy to understand, and simple enough to extend.
Whenever you have a syntax problem with your YAML files, the library outputs a helpful message with the filename and the line number where the problem occurred. It eases the debugging a lot.
It is also able to dump PHP arrays to YAML with object support, and inline level configuration for pretty outputs.
It supports most of the YAML built-in types like dates, integers, octals, booleans, and much more…
Full support for references, aliases, and full merge key. Don’t repeat yourself by referencing common configuration bits.
YAML files are dynamic. By embedding PHP code inside a YAML file, you have even more power for your configuration files.
Symfony YAML can be installed by downloading the source code as a tar archive or a zip one.
To stay up-to-date, you can also use the official Subversion repository.
If you are a Git user, there is an official mirror, which is updated every 10 minutes.
If you prefer to install the component globally on your machine, you can use the symfony PEAR channel server.
Support questions and enhancements can be discussed on the mailing-list.
If you find a bug, you can create a ticket at the symfony trac under the YAML component.
The Symfony YAML component is licensed under the MIT license:
Copyright (c) 2008-2009 Fabien Potencier
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.