phpaddiction » axial

PHP Application Configuration with YAML

Doug Hill — Thu, 22 Nov 2007 12:00:30 +0000

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.

I wanted the following functionality.

Use the YAML format
Minimize load time by caching configuration data
Use object notation instead of array access notation.

I discovered various configuration classes but none of them quite had everything I was looking for so I put together the best code and ideas (for my purposes) that I found to create the Axial_Configuration class.

The Base

During my search for a configuration class I discovered the Zend_Config class which is a perfect fit as far as my object notation requirements. However Zend_Config lacks a YAML implementation and has no cache functionality. I decided to base my class on the Zend_Config ideas to achieve the object notation functionality and added on YAML and cache support.

The YAML format

If you are unfamiliar with the YAML format you probably want to read the following. I won't go into the specifics as they are covered in depth elsewhere.

I discovered YAML while doing some research into various PHP configuration formats a while back and immediately clicked with it. I found two YAML parsers for PHP Spyc a simple php yaml class and the Syck extension. Most of my development is done with shared hosting in mind so the Syck extension isn't an option for now.

Make it Faster

Since loading and parsing YAML in PHP is not the fastest operation I would love to use the Syck extension but in order to ensure compatibility in a variety of environments I implemented a caching scheme using var_export() and the magic method __set_state(). Testing shows a load time decrease of about 30x to 50x for cached data.

Try it out

I know there are dozens of other configuration classes out there but hey "variety is the spice of life. — William Cowper. I don't have much in documentation for it but here is a little bit of code to show you basic usage.

//create an instance that is read only and cached in the current directory.
//you will need to make sure that the directory is writeable.
$config = new Axial_Configuration_Yaml('config.yaml',true,'./');
echo 'File: '.$config->file . '.
';
echo 'Purpose: '.$config->purpose . '.
';
echo 'Data: '.print_r($config->data->toArray(),true) . '.
';

Requirements

PHP 5.1+

You can download the code and try it out. Let me know if you find it useful ¦ or not.

Url Routing with PHP – Part One

Doug Hill — Tue, 27 Mar 2007 17:38:07 +0000

Most PHP frameworks use some variation of the front controller pattern to centralize common code and logic. There are advantages and disadvantages to this. I am going to ignore those for now. In fact the first part of this series will explore a simple procedural URL routing method that contains many of the disadvantages. In later articles we will build upon this basis and address the disadvantages.

Requirements

PHP
Apache with mod_rewrite enabled.

Redirecting with mod_rewrite

This article doesn't discuss mod_rewrite and the .htaccess in detail, the following .htaccess file is sufficient for the needs of our simple front controller. The .htaccess file should be placed in the same directory as the front controller script. All requests will be sent to index.php while requests for a file or directory that does exist will bypass the mod_rewrite rules and be served directly by the web server.

file: .htaccess

Options +FollowSymLinks
IndexIgnore */*
# Turn on the RewriteEngine
RewriteEngine On
# Rules
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php

The Entry Point

I chose a simple format for the incoming URL, a command followed by its parameters separated by forward slashes "/".

For example:
www.example.com/command/parameter1/parameter2/

$requestURI = explode('/', $_SERVER['REQUEST_URI']);

in this example $requestURI would contain.

Array ( [0] => [1] => command [2] => parameter1 [3] => parameter2 [4] => )

This works fine except in the case where the front controller is not in the root directory.

For example:
www.example.com/myapps/app1/command/parameter1/parameter2/

in this case $requestURI would contain.

Array ( [0] => [1] => myapps [2] => app1 [3] => command [4] => parameter1 [5] => parameter2 [6] => )

To filter out the path to the front controller we will need to use the $_SERVER['SCRIPT_NAME'] variable.

$requestURI = explode('/', $_SERVER['REQUEST_URI']);
$scriptName = explode('/',$_SERVER['SCRIPT_NAME']);

In the above example $scriptName would contain.

Array ( [0] => [1] => myapps[2] => app1 [3] => index.php )

Which can be used to remove the path and script name from the URI.
Note: As you can see the explode method leaves an empty array member at the first position. This will be fixed by the following code.

$requestURI = explode('/', $_SERVER['REQUEST_URI']);
$scriptName = explode('/',$_SERVER['SCRIPT_NAME']);
for($i= 0;$i < sizeof($scriptName);$i++)
{
if ($requestURI[$i] == $scriptName[$i])
{
unset($requestURI[$i]);
}
}
$command = array_values($requestURI);

After the code above $command would contain.

Array ( [0] => command [1] => parameter1 [2] => parameter2  [3] => )

Dispatching the command

Now that we have a command with its parameters stored in an array it is trivial to handle them via a switch statement. The following is a short example.

switch($command[0])
{
case 'commandOne' :
echo 'You entered command: '.$command[0];
break;
case 'commandTwo' :
echo 'You entered command: '.$command[0];
break;
default:
echo 'That command does not exist.';
break;
}

Try it out

You can visit examples.phpaddiction.com/urlrouter/part_1/ to see it in action and download the sample code.

Next up

The next part in the series will focus on moving the URL router into a class and out of the global namespace.

Update I've updated the .htaccess per the comment made by DrBacchus.

Yet another PHP framework

Doug Hill — Tue, 13 Mar 2007 09:13:15 +0000

Call it NIH, re-inventing the wheel, narcissism, or any number of other terms that come to mind, but I've always wanted to write my own PHP framework. Simple time constraints usually stop this self destructive urge in its tracks, but I've decided that I'm tired of saying to myself "Framework PHPxyz would be great if only it had ABC.". So it is time to Just Do It.

No matter how much this project screams ego, my real objective is to learn and share with my fellow PHP addicts. I intend to chronicle the project here on phpaddiction.com as part of an experimental development process. I haven't thought of a buzzword for this process yet but you know its coming! All egomaniacs who impose new frameworks on the world instead of working on an existing one must coin new buzzwords to help justify their pet project and I don't intend to be left out.

Oh and hopefully we all learn something too.