StackFormation\ValueResolver\Stage\ProfileSwitcher::invoke PHP Method

    public function invoke($string)
    {
        $string = preg_replace_callback('/\\[profile:([^:\\]\\[]+?):([^\\]\\[]+?)\\]/', function ($matches) {
            // [profile:...] ignores AWS_UNSET_PROFILE. Backup up value here
            $unsetProfileBackup = getenv('AWS_UNSET_PROFILE');
            putenv('AWS_UNSET_PROFILE');
            // recursively create another ValueResolver, but this time with a different profile
            $subValueResolver = new \StackFormation\ValueResolver\ValueResolver($this->valueResolver->getDependencyTracker(), $this->valueResolver->getProfileManager(), $this->valueResolver->getConfig(), $matches[1]);
            $value = $subValueResolver->resolvePlaceholders($matches[2], $this->sourceBlueprint, $this->sourceType, $this->sourceKey);
            // restoring AWS_UNSET_PROFILE value if it was set before
            if ($unsetProfileBackup) {
                putenv('AWS_UNSET_PROFILE=1');
            }
            return $value;
        }, $string);
        return $string;
    }