How can I tell my application about a base path?

In some environments, your application may be running in a subdirectory of your web root. For example:

var/
|- www/
|  |- wordpress/
|  |- expressive/
|  |  |- public/
|  |  |  |- index.php

where /var/www is the web root, and your Expressive application is in the expressive/ subdirectory. How can you make your application work correctly in this environment?

.htaccess in the application root.

If you are using Apache, your first step is to add an .htaccess file to your application root, with directives for rewriting to the public/ directory:

RewriteEngine On
RewriteRule (.*) ./public/$1

Using other web servers

If you are using a web-server other than Apache, and know how to do a similar rewrite, we'd love to know! Please submit ideas/instructions to our issue tracker!

Use middleware to rewrite the path

The above step ensures that clients can hit the website. Now we need to ensure that the application can route to middleware!

To do this, we will add pipeline middleware to intercept the request, and rewrite the URL accordingly.

At the time of writing, we have two suggestions:

los/basepath

To use los/basepath, install it via Composer, copy the configuration files to your application, and then edit the configuration.

To install and copy the configuration:

$ composer require los/basepath
$ cp vendor/los/basepath/config/los-basepath.global.php.dist config/autoload/los-basepath.global.php

We recommend copying the global configuration to a local configuration file as well; this allows you to have the production settings in your global configuration, and development settings in a local configuration (which is excluded from git by default):

$ cp config/autoload/los-basepath.global.php config/autoload/los-basepath.local.php

Then edit one or both, to change the los_basepath settings:

return [
    'los_basepath' => '<base path here>',
    /* ... */
];

The base path should be the portion of the web root leading up to the index.php of your application. In the above example, this would be /expressive.

mtymek/blast-base-url

To use mtymek/blast-base-url, install it via Composer, and register some configuration.

To install it:

$ composer require mtymek/blast-base-url

To configure it, update the file config/autoload/middleware-pipeline.global.php, with the following contents:

return [
    'dependencies' => [
        'factories' => [
            Blast\BaseUrl\BaseUrlMiddleware::class => Blast\BaseUrl\BaseUrlMiddlewareFactory::class,
            /* ... */
        ],
        /* ... */
    ],
    'middleware_pipeline' => [
        [ 'middleware' => [ Blast\BaseUrl\BaseUrlMiddleware::class ], 'priority' => 1000 ],
        /* ... */
        'routing' => [
            'middleware' => [
                Zend\Expressive\Container\ApplicationFactory::ROUTING_MIDDLEWARE,
                Zend\Expressive\Helper\UrlHelperMiddleware::class,
                Zend\Expressive\Container\ApplicationFactory::DISPATCH_MIDDLEWARE,
            ],
            'priority' => 1,
        ],
        /* ... */
    ],
];

At this point, the middleware will take care of the rewriting for you. No configuration is necessary, as it does auto-detection of the base path based on the request URI and the operating system path to the application.

The primary advantage of mtymek/blast-base-url is in its additional features:

To enable these features, we'll add some configuration to config/autoload/dependencies.global.php file:

return [
    'dependencies' => [
        'invokables' => [
            Blast\BaseUrl\BasePathHelper::class => Blast\BaseUrl\BasePathHelper::class,
            /* ... */
        ],
    ],
];

Finally, if you're using zend-view, you can register a new "basePath" helper in your config/autoload/templates.global.php:

return [
    /* ... */
    'view_helpers' => [
        'factories' => [
            'basePath' => Blast\BaseUrl\BasePathViewHelperFactory::class,
            /* ... */
        ],
        /* ... */
    ],
];

Usage of the BasePath helper is as follows:

// where $basePathHelper is an instance of Blast\BaseUrl\BasePathHelper
// as pulled from your container:
echo $basePathHelper('/icons/favicon.ico');

// or, from zend-view's PhpRenderer:
echo $this->basePath('/icons/favicon.ico');