Struct EvaluationContext

pub struct EvaluationContext {
    pub targeting_key: Option<String>,
    pub custom_fields: HashMap<String, EvaluationContextFieldValue>,
}

The evaluation context provides ambient information for the purposes of flag evaluation. Contextual data may be used as the basis for targeting, including rule-based evaluation, overrides for specific subjects, or fractional flag evaluation.

The context might contain information about the end-user, the application, the host, or any other ambient data that might be useful in flag evaluation. For example, a flag system might define rules that return a specific value based on the user’s email address, locale, or the time of day. The context provides this information. The context can be optionally provided at evaluation, and mutated in before hooks.

Fields

targeting_key: Option<String>

The targeting key uniquely identifies the subject (end-user, or client service) of a flag evaluation. Providers may require this field for fractional flag evaluation, rules, or overrides targeting specific users. Such providers may behave unpredictably if a targeting key is not specified at flag resolution.

custom_fields: HashMap<String, EvaluationContextFieldValue>

The evaluation context MUST support the inclusion of custom fields, having keys of type string, and values of type boolean | string | number | datetime | structure.

Implementations

impl EvaluationContext

pub fn with_targeting_key(self, targeting_key: impl Into<String>) -> Self

Set the targeting_key of the evaluation context.

pub fn with_custom_field( self, key: impl Into<String>, value: impl Into<EvaluationContextFieldValue>, ) -> Self

Add key and value to the custom field of evaluation context.

pub fn add_custom_field( &mut self, key: impl Into<String>, value: impl Into<EvaluationContextFieldValue>, )

Add key and value to the custom field of evaluation context.

pub fn merge_missing(&mut self, other: &Self)

Merge other into self if corresponding field is not set. Meaning values set into self has higher precedence.

Trait Implementations

impl Clone for EvaluationContext

fn clone(&self) -> EvaluationContext

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for EvaluationContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for EvaluationContext

fn default() -> EvaluationContext

Returns the “default value” for a type.

impl PartialEq for EvaluationContext

fn eq(&self, other: &EvaluationContext) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for EvaluationContext