Framework Documentation - Application Package

Configuration

The application owns a Joomla\Registry\Registry instance. Everything the application and its
listeners need to know about the environment lives there.

Reading and writing

$app->get('key');                 // null if unset
$app->get('key', 'default');
$app->get('database.host');       // dot notation traverses nested data

$previous = $app->set('key', 'value');   // returns the value that was there before
$app->setConfiguration($registry);       // replace the whole registry, fluent

AbstractApplication::get() delegates to Registry::get(). Two behaviours of the registry are
worth knowing because they surprise people:

An empty string reads back as the default. Registry::get() treats '' like "not set", so
$app->set('prefix', ''); $app->get('prefix', 'jos_'); returns 'jos_', not ''. If you need to
express "deliberately empty", use a sentinel value or read $registry->exists() instead.
The separator is . by default. A key that itself contains a dot cannot be addressed.

Supplying configuration

Pass a registry to the constructor:

$app = new MyApplication(input: null, config: new Registry($data));

Or load it from a file — the registry supports JSON, INI, XML, YAML and PHP:

use Joomla\Registry\Registry;

$config = new Registry();
$config->loadFile(__DIR__ . '/config/app.json', 'JSON');

Registry::loadFile() does not check whether the file could be read. A missing or unreadable
file yields an empty registry, not an error. Check the path yourself before loading, or the
application will silently start with every setting on its default.

Keys the package writes

These are set by the application itself; treat them as read-only.

Key	Set by	Contents
`execution.datetime`	`AbstractApplication::__construct()`	`gmdate('Y-m-d H:i:s')` at boot
`execution.timestamp`	`AbstractApplication::__construct()`	`time()` at boot
`execution.microtimestamp`	`AbstractApplication::__construct()`	`microtime(true)` at boot
`uri.request`	`loadSystemUris()`	Full URI of the current request
`uri.base.full`	`loadSystemUris()`	Scheme, host, port and base path, with trailing slash
`uri.base.host`	`loadSystemUris()`	Scheme, host and port only
`uri.base.path`	`loadSystemUris()`	Base path only, with trailing slash
`uri.route`	`loadSystemUris()`	`uri.request` minus `uri.base.full` — this is what you route on
`uri.media.full`	`loadSystemUris()`	Absolute URI of the media folder
`uri.media.path`	`loadSystemUris()`	Path of the media folder

uri.route is only set when uri.request actually starts with uri.base.full. Behind a rewriting
proxy that changes the path, it can be missing — WebApplication::doExecute() then routes on null.

Keys the package reads

Key	Read by	Effect
`gzip`	`AbstractWebApplication::execute()`	When truthy, and neither `zlib.output_compression` nor `ob_gzhandler` is active, the body is compressed with gzip or deflate depending on `Accept-Encoding`
`site_uri`	`loadSystemUris()`	Overrides base URI detection. Set this whenever the application runs behind a proxy or in a sub-directory — detection uses `SCRIPT_NAME`/`PHP_SELF` and gets it wrong often enough to be worth pinning
`media_uri`	`loadSystemUris()`	Overrides the media folder location. A value containing `://` is used verbatim, otherwise it is treated as a path below `uri.base.host`

Public properties that act as configuration

AbstractWebApplication exposes four public properties rather than config keys. They are read
during respond():

$app->charSet     = 'utf-8';      // appended to the Content-Type header
$app->mimeType    = 'text/html';  // the Content-Type header
$app->httpVersion = '1.1';        // used in the status line
$app->modifiedDate = new DateTime('2026-01-01');  // Last-Modified, only when caching is allowed

Set mimeType before the response is sent, for example in a controller:

$app->mimeType = 'application/json';
$app->setBody(json_encode($data, JSON_THROW_ON_ERROR));

A worked example

use Joomla\Registry\Registry;

$configFile = __DIR__ . '/config/app.json';

if (!is_readable($configFile)) {
    throw new RuntimeException(sprintf('Configuration file "%s" is not readable.', $configFile));
}

$config = (new Registry())->loadFile($configFile, 'JSON');

// Pin the base URI instead of relying on detection.
$config->set('site_uri', 'https://example.com/app/');
$config->set('media_uri', 'https://cdn.example.com/assets/');
$config->set('gzip', true);

$app = new MyApplication(null, $config);