Extending / Basics / Configuration

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It is very useful to allow users of your application control over how it behaves.

Bolt uses configuration files in the YAML format, and the same is true for extensions.

Should you wish to provide a configuration file for your extension users, you need to create the template as config/config.yml.dist. Upon installation, that file will be copied to Bolt's app/config/extensions/ directory and be renamed to the lower-case version of extension_name.vendor_name.yml

Configuration Files¶

The layout of YAML configuration files needs to adhere to the Symfony YAML format.

pets:
    kittens: 11
    puppies: 12
    turtles: 13

Providing Defaults¶

Sometimes things are accidentally removed, or even added to the extension and older configuration files not updated.

To cope with this, Bolt extensions can define a getDefaultConfig() function that returns an array of parameters that will have user specified parameters merged over the top of.

An example of this would look like:

    /**
     * {@inheritdoc}
     */
    protected function getDefaultConfig()
    {
        return [
            'pets' => [
                'kittens' => 10,
                'puppies' => 20,
                'turtles' => 30,
            ]
        ];
    }

In the above example, puppies would have a default value of 20, unless a value was specificed in the configuration file, in that case the provided value would override this default.

Accessing Configuration Values¶

An extension's configuration array can simply be accessed with the getConfig() function.

$config = $this->getConfig();

echo 'We are configured to pat ' . $config['pets']['kittens'] . ' kittens.';

NOTES:

• Configuration files are lazy loaded, so the $config class parameter is private and can not be directly accessed.
• The getConfig() function is protected to prevent leaking of configuration data. Should you need your configuration data to be shared, you can either:
  • Pass in the configuration array from $this->getConfig() to class constructors
  • Extend getConfig() and call return parent::getConfig();