Struct ObserverDefinition 

pub struct ObserverDefinition {
    pub name: String,
    pub entity: String,
    pub event: String,
    pub condition: Option<String>,
    pub actions: Vec<Value>,
    pub retry: RetryConfig,
}

Observer definition - database change event listener.

Observers trigger actions (webhooks, notifications) when database changes occur, enabling event-driven architectures.

Example

use fraiseql_core::schema::{ObserverDefinition, RetryConfig};

let observer = ObserverDefinition {
    name: "onHighValueOrder".to_string(),
    entity: "Order".to_string(),
    event: "INSERT".to_string(),
    condition: Some("total > 1000".to_string()),
    actions: vec![
        serde_json::json!({
            "type": "webhook",
            "url": "https://api.example.com/high-value-orders"
        }),
    ],
    retry: RetryConfig {
        max_attempts: 3,
        backoff_strategy: "exponential".to_string(),
        initial_delay_ms: 1000,
        max_delay_ms: 60000,
    },
};

Fields

name: String

Observer name (unique identifier).

entity: String

Entity type to observe (e.g., “Order”, “User”).

event: String

Event type: INSERT, UPDATE, or DELETE.

condition: Option<String>

Optional condition expression in FraiseQL DSL. Example: “total > 1000” or “status.changed() and status == ‘shipped’”

actions: Vec<Value>

Actions to execute when observer triggers. Each action is a JSON object with a “type” field (webhook, slack, email).

retry: RetryConfig

Retry configuration for action execution.

Implementations

impl ObserverDefinition

pub fn new( name: impl Into<String>, entity: impl Into<String>, event: impl Into<String>, ) -> Self

Create a new observer definition.

pub fn with_condition(self, condition: impl Into<String>) -> Self

Set the condition expression.

pub fn with_action(self, action: Value) -> Self

Add an action to this observer.

pub fn with_actions(self, actions: Vec<Value>) -> Self

Add multiple actions to this observer.

pub fn with_retry(self, retry: RetryConfig) -> Self

Set the retry configuration.

pub const fn has_condition(&self) -> bool

Check if this observer has a condition.

pub const fn action_count(&self) -> usize

Get the number of actions.

Trait Implementations

impl Clone for ObserverDefinition

fn clone(&self) -> ObserverDefinition

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ObserverDefinition

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ObserverDefinition

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ObserverDefinition

fn eq(&self, other: &ObserverDefinition) -> 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 Serialize for ObserverDefinition

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for ObserverDefinition

impl StructuralPartialEq for ObserverDefinition