Question

I am working on a new PHP project now, this time I want to get the basics right at the beginning. Previously I’ve found requiring/including files in php a bit of pain, please consider the following structure:

/application_root/index.php
                 /js/...
                 /css/...
                 /php/...
                 /conf/...
                 ...

In the index.php I can certainly use something like:

<link rel="stylesheet" href="css/sample.css" ... />
<script type="text/javascript" src="js/sample.js"></script>

To refer to the included css and js, or even php snippets. However, this would only work in the index.php which resides under the root of my application folder. I reckon this is no good.

I came across Java application configuration file “web.xml” where you can define application scope variables that you can simply refer to. .NET with C# has a similar thing. How to achieve this in simple php code so that from any php file in my app, I can type:

<?php echo "<link href='".$application_root_url."/php/sample.css' ..."; ?>

And it will evaluate to the right location?

I am thinking to use:

• Global variables <== bad practice as violation to OOP? I stop doing this since c programming;
• set_include_path <== so php will look for it, requires unique name and proper naming convention?
• load variables from ini files? <== how to make this happen?
• any new thoughts?

Answer 1

You don’t want to use global variables because they break encapsulation.

set_include_path will do no good especially if you are using those variables in HTML, because the include_path is relative to the application’s filesystem path and not to its base url.

Determining the application base paths is generally not done from a configuration file, as it easy to detect when your application has a gateway script. Since those are constant values, it makes sense to define a constant:

define('APP_ROOT', dirname(__FILE__));
define('APP_URL', dirname($_SERVER['PHP_SELF']));

If you want to parse INI files however, you could use parse_ini_file, or parse_ini_string (>=5.3.0):

$config = parse_ini_file(APP_ROOT.'/'.CONFIG_DIR.'/database.ini');
echo $config['host'];