Feature Flags

All new features should be released behind Feature Flags.

We have a plugin called FeatureFlags that does all the heavy lifting for you. All you have to do is call it to find out if the new fancy code should be executed or not.

Dashboard

You can access the Feature Flags Dashboard by clicking Admin -> Feature Flags in the left hand nav menu of any client interface.

Best Practices

Feature Flags should be affirimative in enabling a new feature. For example the flag to turn on the sending of notifications is called notification_sending_enabled and it must be postitive rather than notification_sending_disabled and it must be negative.

This is because all unset flags default to false. This allows us to roll out new code with no functional or visible changes until we enable that feature. If something goes wrong with the feature we can disable it and everything goes back to how it used to be.

Helper

The most commonly used bit is the helper.

Displaying feature flag status

echo $this->FeatureFlags->getStatusBadge("notification_sending_enabled")

Getting flag value for use in a conditional

$notification_sending_enabled = $this->FeatureFlags->getFlagValue("notification_sending_enabled")

echo $this->FeatureFlags->getToggleLink("notification_sending_enabled")

Behavior

If you need to access Feature Flags within a model's tabel, just include the behavior in the Tabel's initialize function $this->addBehavior('FeatureFlags.FeatureFlags');

Now you can query flags directly $notifications_enabled = $this->getFeatureFlagValue("notification_sending_enabled");

Component

If you need to access Feature Flags within a Controller, you can use the Component that is included in all Controllers by default via AppController::initialize.

You can query flags from controllers like so $home_screen_enabled = $this->FeatureFlags->getFlagValue("home_screen")