How can I programmatically install a plugin?

Question

How could you do programmatically what Joomla does when you install a plugin? Let's say, for simplicity's sake, that you have a plugin package file local with your Joomla instance.

A solution might look like one of:

• a) You make a POST request to a Joomla endpoint with the package file that installs the plugin.

• b) You write a shell script that both installs the package file's contents in the correct folder, and writes the required data to the db (more brittle this way).

Answer 1

Use Install model.

if (!defined('_JEXEC'))
{
    define('_JEXEC', 1);
    define('JPATH_BASE', realpath(__DIR__));
    require_once JPATH_BASE . '/includes/defines.php';
    require_once JPATH_BASE . '/includes/framework.php';
}

JModelLegacy::addIncludePath(JPATH_ADMINISTRATOR . '/components/com_installer/models', 'InstallerModel');
$input = JFactory::getApplication('site')->input;
$input->set('installtype', 'folder');
$input->set('install_directory', $path);
$model = JModelLegacy::getInstance('Install', 'InstallerModel', array('ignore_request' => true));
$model->install();

Where $path is path to extension installation files.