Custom Strategies

Implementing a custom strategy

• Set up a custom strategy in Unleash. Note down the name - you’ll need this exact value to ensure we’re loading the custom strategy correctly.

• Create a custom strategy object by sub-classing the Strategy object.

from UnleashClient.strategies.Strategies import Strategy

class CatTest(Strategy):
    def load_provisioning(self) -> list:
        return [x.strip() for x in self.parameters["sound"].split(',')]

    def apply(self, context: dict = None) -> bool:
        """
        Turn on if I'm a cat.

        :return:
        """
        default_value = False

        if "sound" in context.keys():
            default_value = context["sound"] in self.parsed_provisioning

        return default_value

• Create a dictionary where the key is the name of the custom strategy. Note: The key must match the name of the custom strategy created on the Unleash server exactly (including capitalization!).

my_custom_strategies = {"amIACat": CatTest}

• When initializing UnleashClient, provide the custom strategy dictionary.

unleash_client = UnleashClient(URL, APP_NAME, custom_strategies=my_custom_strategies)

• Fire up Unleash! You can now use the “amIACat” strategy in a feature toggle.

Migrating your custom strategies from Strategy from v2.x.x to v3.x.x (for fun and profit)

To get support for for constraints in your custom strategy, take the following steps:

• Instead of overriding the __call__() method, override the apply() method. (In practice, you can just rename the method!)

• ???

• Profit!