Concepts: Rules Engine Filter

Rules Engine Filter

Using the custom filter and operators, you can only configure simple expressions (like In, Equals, Greater than, etc.). Another drawback is joining expressions. If you configure multiple filters for a feature flag, the flag will be evaluated to true even if 1 of the filter conditions is evaluated to true. Hence you evaluate the final result by combining results from multiple filters.

For such complex scenarios you can use RulesEngine filter. RulesEngine is an open-source library that can create JSON-based workflows to evaluate rules and complex conditions. You can check the details of Rules Engine in its GitHub repository.

Integration

For utilizing Rules Engine, you will need to create a filter of type RulesEngine, and configure the name of the Workflow/JSON file which contains the rule. The JSON file is kept in an Azure Storage Blob. Tenants who are interested in using Rules Engine filter must provide the Storage Connection String (with Read permission) and the name of the Container where the JSON files will be kept.

Each workflow in a rule engine can have multiple Rules, the feature flag will be evaluated to true only if all the rules passes.

Additional Operators