Struct MessageEvent 

pub struct MessageEvent {
    pub code: i32,
    pub numeric: f64,
    pub text: String,
    pub payload: Option<String>,
    pub synchronous: bool,
    pub execution_id: Option<i32>,
}

One message, flattened into something that can cross a thread or a wire.

The COM objects a UIMessage refers to are bound to the engine’s apartment and cannot leave it, so what travels is the data a consumer actually needs.

Fields

code: i32

The raw message code.

numeric: f64

The numeric payload.

Serialized so a non-finite value never reaches the wire as null: JSON has no NaN or infinity, and a strictly typed reader that expects a number cannot accept one.

text: String

The string payload.

payload: Option<String>

The object payload, as JSON.

A message’s third slot holds an ActiveX reference, which is how a sequence hands over a whole container instead of packing fields into text. That reference is bound to the engine’s process and cannot be sent anywhere, so what survives here is the tree walked into data. None means the slot was empty or the policy declined it.

synchronous: bool

Whether the posting thread was blocked awaiting acknowledgement.

Informational by the time a subscriber sees it: the host has already acknowledged the message, because holding it would stall the sequence.

execution_id: Option<i32>

The execution that posted it, when there was one.

Implementations

impl MessageEvent

pub const fn is_from_sequence(&self) -> bool

Whether a sequence posted this, rather than the engine.

pub fn engine_code(&self) -> Option<UIMessageCode>

The engine’s name for the code, when it has one.

pub fn from_ui_message( message: &UIMessage, policy: PayloadPolicy, ) -> Result<Self, Error>

Flattens a live message into something that can leave this process.

This is the boundary. Everything a UIMessage refers to is bound to the engine’s apartment; everything on this side of the call is data, and can go to another thread, another process, or a socket.

All three payload slots are carried, including the object one, which is the slot that makes the difference: a sequence can put a container in it and a receiver gets the whole structure without either side agreeing on a text format. policy decides when that is worth the cost.

Errors

Error if a COM call fails or the object cannot be walked.

Trait Implementations

impl Clone for MessageEvent

fn clone(&self) -> MessageEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MessageEvent

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MessageEvent

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for MessageEvent

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for MessageEvent

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for MessageEvent