Symphony.

Does anybody know if there is a standard method in the Symphony core to check if a certain extension is installed? I like to check if JIT image manipulation is installed and enabled.

Use this code to see if JIT image manipulation is enabled (which means it is installed, or not?):

$extensionManager = new ExtensionManager($this->_Parent);

if($extensionManager->fetchStatus('jit_image_manipulation') == 'EXTENSION_ENABLED') {
    // Your code here
}

To grab a list of all installed extensions, use $extensionManager->listInstalledHandles();

Thanks carsten, this is very helpful!