Trait Feature 

pub trait Feature {
    // Required methods
    fn get_name(&self) -> Result<String>;
    fn is_enabled(&self) -> Result<bool>;
    fn get_value(&self, entity: &impl Entity) -> Result<Value>;
    fn get_value_into<T: TryFrom<Value, Error = Error>>(
        &self,
        entity: &impl Entity,
    ) -> Result<T>;
}

Access to data and evaluation of IBM AppConfiguration features

Required Methods

fn get_name(&self) -> Result<String>

Returns the full name of the feature.

fn is_enabled(&self) -> Result<bool>

Returns if the feature is enabled or not.

An enabled feature should be evaluated for each Entity to get the corresponding value. However, disabled features won’t be evaluated and will always return the disabled value.

fn get_value(&self, entity: &impl Entity) -> Result<Value>

Evaluates a feature for the given Entity and returns a Value.

Use the methods available in Value to return the actual primitive value. If all you want is the primitive value, you can use the method get_value_into instead.

Examples

    let feature = client.get_feature("my_feature")?;
    let value: Value = feature.get_value(entity)?;

    match value {
        Value::Float64(v) => println!("f64 with value {v}"),
        Value::UInt64(v) => println!("u64 with value {v}"),
        Value::Int64(v) => println!("i64 with value {v}"),
        Value::String(v) => println!("String with value {v}"),
        Value::Boolean(v) => println!("bool with value {v}"),
    }

fn get_value_into<T: TryFrom<Value, Error = Error>>( &self, entity: &impl Entity, ) -> Result<T>

Evaluates a feature for the given Entity and returns its value converted (if possible) to the given type.

Examples

    let feature = client.get_feature("my_f64_feature")?;
    let value: f64 = feature.get_value_into(entity)?;

    // an f64 cannot be returned as u64
    let failed: Result<u64> = feature.get_value_into(entity);
    assert!(failed.is_err());

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors