Magento 2: More on Setting Area Codes

Reader Vinai Kopp (of Mage2Katas fame) wrote in with a interesting bit of functionality in the MagentoFrameworkAppState class we talked about in the Fixing Area code Not Set Exceptions quickie.

Specifically, Vinai had a bit of code that was shared between a command line context, and a web context, and if he tried setting the area code during the web context, Magento would throw a different exception

Area code is already set

That’s because of the following guard clause

#File: vendor/magento/framework/App/State.php
public function setAreaCode($code)
{
    if (isset($this->_areaCode)) {
        throw new MagentoFrameworkExceptionLocalizedException(
            new MagentoFrameworkPhrase('Area code is already set')
        );
    }
    $this->_configScope->setCurrentScope($code);
    $this->_areaCode = $code;
}

The MagentoFrameworkAppState object will only let you set a value once – after that, the area for a specific request/cli-run is immutable. Vinai was kind enough to share his solution

public function __construct(
    MagentoFrameworkAppState $appState,
    $name=null
) {
    try {
        $appState->setAreaCode('frontend');
    } catch (MagentoFrameworkExceptionLocalizedException $e) {
        // intentionally left empty
    }
    parent::__construct($name);
}

By catching the exception Magento throws and silently ignoring it, Vinai was able to ensure his class/object worked in both a command line context, and in a web context.